jiaoyu/backend/services/ai_service.py

import json
import re
import html as html_lib
import httpx
import logging
import time
import base64
from config import get_settings

settings = get_settings()
logger = logging.getLogger(__name__)


class AIService:
    # Shared circuit-breaker timestamp: all instances share one breaker so a
    # single AI outage trips the breaker globally across every router.
    _ai_unavailable_until: float = 0.0

    def __init__(self):
        self.api_key = settings.AI_API_KEY
        self.api_base = settings.AI_API_BASE.rstrip("/")
        self.model = settings.AI_MODEL
        self.client = httpx.AsyncClient(
            base_url=self.api_base,
            headers={"Authorization": f"Bearer {self.api_key}"},
            timeout=httpx.Timeout(connect=10.0, read=120.0, write=15.0, pool=10.0),
        )

    async def _chat(self, messages: list[dict], temperature: float = 0.7, max_tokens: int = 8192) -> str:
        if time.monotonic() < AIService._ai_unavailable_until:
            logger.warning("AI provider skipped (circuit breaker active for %.0fs more)", AIService._ai_unavailable_until - time.monotonic())
            raise RuntimeError("AI_PROVIDER_UNAVAILABLE")
        try:
            response = await self.client.post(
                "/chat/completions",
                json={
                    "model": self.model,
                    "messages": messages,
                    "temperature": temperature,
                    "max_tokens": max_tokens,
                    # glm-5.x is a reasoning model: without disabling
                    # thinking it burns the entire token budget on
                    # chain-of-thought and returns EMPTY content
                    # (finish_reason=length), forcing every feature to
                    # fall back to static templates. Disable for real output.
                    "enable_thinking": False,
                    "thinking": {"type": "disabled"},
                },
            )
            response.raise_for_status()
        except httpx.ConnectError as exc:
            # Connection-level failure: server likely down. Short breaker so we retry sooner.
            logger.error("AI provider connect failed: %s: %s", type(exc).__name__, exc)
            AIService._ai_unavailable_until = time.monotonic() + 20
            raise RuntimeError("AI_PROVIDER_CONNECT_ERROR") from exc
        except httpx.TimeoutException as exc:
            # Timeout (connect/read): server slow or unreachable. Short breaker.
            logger.error("AI provider timeout: %s: %s", type(exc).__name__, exc)
            AIService._ai_unavailable_until = time.monotonic() + 20
            raise RuntimeError("AI_PROVIDER_TIMEOUT") from exc
        except httpx.HTTPStatusError as exc:
            # HTTP error (4xx/5xx): server is up but rejected the request.
            logger.error("AI provider HTTP %s: %s", exc.response.status_code, str(exc.response.text)[:200])
            breaker = 30 if exc.response.status_code >= 500 else 120
            AIService._ai_unavailable_until = time.monotonic() + breaker
            raise RuntimeError("AI_PROVIDER_HTTP_ERROR") from exc
        except Exception as exc:
            logger.error("AI provider request failed: %s: %s", type(exc).__name__, exc)
            AIService._ai_unavailable_until = time.monotonic() + 30
            raise RuntimeError("AI_PROVIDER_UNAVAILABLE") from exc
        data = response.json()
        content = data["choices"][0]["message"]["content"] or ""
        # Reasoning models may return empty content if thinking consumed the token budget
        if not content.strip():
            logger.warning("AI provider returned empty content (finish=%s, model=%s) - reasoning budget likely exhausted", data["choices"][0].get("finish_reason","?"), self.model)
            raise RuntimeError("AI_PROVIDER_EMPTY_RESPONSE")
        finish_reason = data["choices"][0].get("finish_reason", "")
        if finish_reason == "length":
            content = content + '..."}'
        return content

    async def _chat_json(self, messages: list[dict], temperature: float = 0.3, max_tokens: int = 8192) -> dict:
        content = await self._chat(messages, temperature, max_tokens)
        return self._extract_json(content)


    async def ocr_image(self, image_bytes: bytes, filename: str = "") -> str:
        """Extract text from an image using the AI model's vision capability."""
        if not self.api_key or self.api_key == "change-me-in-production":
            raise RuntimeError("AI_PROVIDER_UNAVAILABLE")
        if time.monotonic() < AIService._ai_unavailable_until:
            raise RuntimeError("AI_PROVIDER_UNAVAILABLE")

        b64 = base64.b64encode(image_bytes).decode("ascii")
        ext = "png"
        lower_name = (filename or "").lower()
        if lower_name.endswith((".jpg", ".jpeg")):
            ext = "jpeg"
        elif lower_name.endswith(".webp"):
            ext = "webp"
        elif lower_name.endswith(".gif"):
            ext = "gif"

        messages = [
            {
                "role": "user",
                "content": [
                    {
                        "type": "text",
                        "text": (
                            "请仔细识别这张图片中的所有文字内容，包括题目、公式、表格和标注。"
                            "完整提取文字，保持原有结构和层次。"
                            "如果是题目，请保留题号和选项格式。"
                            "数学公式用可读文本表示（例如 a² + b² = c²）。"
                            "只输出识别到的文字内容，不要添加解释或说明。"
                            "如果图片中没有文字或无法识别，请回复：[无法识别文字内容]"
                        ),
                    },
                    {
                        "type": "image_url",
                        "image_url": {"url": f"data:image/{ext};base64,{b64}"},
                    },
                ],
            }
        ]

        try:
            response = await self.client.post(
                "/chat/completions",
                json={
                    "model": self.model,
                    "messages": messages,
                    "temperature": 0.1,
                    "max_tokens": 4096,
                    "enable_thinking": False,
                    "thinking": {"type": "disabled"},
                },
            timeout=httpx.Timeout(connect=10.0, read=90.0, write=15.0, pool=10.0),
            )
            response.raise_for_status()
        except Exception as exc:
            logger.error("Vision OCR request failed: %s", exc)
            AIService._ai_unavailable_until = time.monotonic() + 60
            raise RuntimeError("AI_PROVIDER_UNAVAILABLE") from exc

        data = response.json()
        return data["choices"][0]["message"]["content"].strip()

    def _extract_json(self, content: str) -> dict:
        content = content.strip()

        # Strip markdown code fences
        import re as _re
        content = _re.sub(r'^```\w*\n?', '', content)
        content = _re.sub(r'\n?```$', '', content)
        content = content.strip()

        first_brace = content.find('{')
        if first_brace == -1:
            return {"raw_content": content}

        last_brace = content.rfind('}')
        if last_brace <= first_brace:
            return {"raw_content": content}

        # Try the full span first
        candidate = content[first_brace:last_brace + 1]
        try:
            result = json.loads(candidate)
            if isinstance(result, dict):
                return result
        except json.JSONDecodeError:
            pass

        # Try auto-fixing truncated JSON by closing open structures
        fixed = self._try_fix_truncated_json(candidate)
        if fixed:
            return fixed

        # Try replacing HTML double quotes with single quotes inside the html field
        fixed2 = _re.sub(r'(style|onclick|onchange)=\\?"([^"]*?)\\?"', r"\1='\2'", candidate)
        if fixed2 != candidate:
            try:
                result = json.loads(fixed2)
                if isinstance(result, dict):
                    return result
            except json.JSONDecodeError:
                pass

        # Find all '}' positions from end to start
        pos = last_brace
        while pos > first_brace:
            if content[pos] == '}':
                try:
                    result = json.loads(content[first_brace:pos + 1])
                    if isinstance(result, dict):
                        return result
                except json.JSONDecodeError:
                    pass
            pos -= 1

        # Last resort: try to extract html field via regex
        html_match = _re.search(r'"html"\s*:\s*"((?:[^"\\]|\\.)*)"', content, _re.DOTALL)
        if html_match:
            try:
                html_val = json.loads('"' + html_match.group(1) + '"')
                return {"title": "动画", "description": "", "html": html_val}
            except:
                pass

        # All attempts failed - save debug info
        try:
            with open("debug_json_fail.txt", "w", encoding="utf-8") as f:
                f.write(f"Content length: {len(content)}\n")
                f.write(f"First 500 chars:\n{content[:500]}\n\n")
                f.write(f"Last 500 chars:\n{content[-500:]}\n\n")
                f.write(f"Full content:\n{content}\n")
        except:
            pass

        return {"raw_content": content}

    def _try_fix_truncated_json(self, candidate: str) -> dict | None:
        """Try to fix truncated JSON by closing open strings/brackets."""
        import re as _re
        # Count brackets
        opens = candidate.count('{') - candidate.count('}')
        opens_bracket = candidate.count('[') - candidate.count(']')

        # Check if we're inside a string
        in_string = False
        escape = False
        for ch in candidate:
            if escape:
                escape = False
                continue
            if ch == '\\':
                escape = True
                continue
            if ch == '"':
                in_string = not in_string

        fixed = candidate
        if in_string:
            fixed += ''
        # Close open string if inside one
        if in_string:
            fixed += '"'
        # Close open brackets
        for _ in range(max(0, opens_bracket)):
            fixed += ']'
        for _ in range(max(0, opens)):
            fixed += '}'

        try:
            result = json.loads(fixed)
            if isinstance(result, dict):
                # If html field exists, this is usable
                if 'html' in result:
                    return result
        except json.JSONDecodeError:
            pass

        # Try simpler fix: just close the outermost object
        if in_string:
            # Find last complete key-value pair before truncation
            # Try: add closing quote, skip to end of object
            for suffix in ['"}', '"}]}', '"}]}', '"]}', '"}' ]:
                try:
                    result = json.loads(candidate + suffix)
                    if isinstance(result, dict):
                        return result
                except json.JSONDecodeError:
                    continue

        return None

    async def chat_teaching(self, history: list[dict], user_message: str, subject: str = "", grade: str = "") -> str:
        """General-purpose conversational teaching assistant (multi-turn)."""
        context_bits = []
        if subject:
            context_bits.append(f"任教学科：{subject}")
        if grade:
            context_bits.append(f"教学学段/年级：{grade}")
        context_line = ("；".join(context_bits) + "。") if context_bits else ""

        system_prompt = (
            "你是“智教助手”，一位经验丰富、耐心细致的 K12 全学科教学顾问与备课搭档。"
            "你的任务是帮助一线教师解决真实的教学问题：备课思路、知识点讲解、活动设计、"
            "课堂提问、学情诊断、家校沟通、教法选择等。\n"
            "回答要求：\n"
            "1. 用简体中文回答，语气专业、亲切、可落地，避免空话套话。\n"
            "2. 结构清晰，善用标题、要点、表格和示例，必要时分步骤说明。\n"
            "3. 紧扣中国课程标准和一线课堂实际，给出可直接使用的内容（如完整提问、活动脚本、讲解话术）。\n"
            "4. 遇到模糊请求时主动追问关键信息（年级、学科、目标、时长）再给出方案。\n"
            "5. 对学生的易错点、认知难点要有针对性提醒；涉及数值/事实要准确。\n"
            f"{context_line}"
        )

        messages: list[dict] = [{"role": "system", "content": system_prompt}]
        for turn in (history or []):
            role = turn.get("role")
            content = (turn.get("content") or "").strip()
            if role in {"user", "assistant"} and content:
                messages.append({"role": role, "content": content})
        messages.append({"role": "user", "content": user_message})
        try:
            return await self._chat(messages, temperature=0.6, max_tokens=8192)
        except RuntimeError:
            return self._fallback_chat(history or [], user_message, subject, grade)

    async def generate_mindmap(self, topic: str, subject: str = "综合", grade: str = "") -> dict:
        """生成知识思维导图，返回层级节点结构。"""
        topic = self._repair_text(topic)
        grade_hint = f"，适用学段：{grade}" if grade else ""
        system_prompt = f"""你是一位资深学科教学专家，擅长梳理知识结构。根据教师给出的主题，生成一份层次清晰、内容专业的知识思维导图。

要求：
- 围绕主题梳理 4 到 6 个一级分支（核心知识维度）
- 每个一级分支下展开 2 到 4 个二级子节点
- 节点标题用精炼短语（4 到 14 字），不要长句
- 内容要符合学科规范与教学逻辑，覆盖该主题的核心知识脉络（学科：{subject}{grade_hint}）
- 如果主题偏小众，也尽量给出合理、可教学的结构

直接输出JSON（不要markdown代码块，不要其他文字）：
{{"title":"主题名","nodes":[{{"title":"一级分支标题","color":"#00a870","children":[{{"title":"二级子节点标题","children":[{{"title":"可展开的细节要点"}}]}}]}}]}}"""
        try:
            result = await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": topic},
            ], temperature=0.5, max_tokens=8192)
            return self._normalize_mindmap_result(result, topic, subject)
        except RuntimeError:
            return self._fallback_mindmap(topic, subject)

    def _normalize_mindmap_result(self, result: dict, topic: str, subject: str) -> dict:
        topic = self._repair_text(topic)
        nodes = result.get("nodes")
        if not isinstance(nodes, list) or not nodes:
            return self._fallback_mindmap(topic, subject)
        palette = ["#00a870", "#2563eb", "#d97706", "#db2777", "#7c3aed", "#0891b2", "#4f46e5", "#ea580c"]
        clean: list = []
        for i, branch in enumerate(nodes):
            if not isinstance(branch, dict) or not str(branch.get("title", "")).strip():
                continue
            color = branch.get("color") or palette[i % len(palette)]
            children = self._collect_mindmap_children(branch.get("children"))
            if not children:
                continue
            clean.append({"title": str(branch["title"]).strip()[:30], "color": color, "children": children})
        if len(clean) < 2:
            return self._fallback_mindmap(topic, subject)
        return {"title": str(result.get("title") or topic)[:80], "nodes": clean[:8]}

    def _collect_mindmap_children(self, raw) -> list:
        if not isinstance(raw, list):
            return []
        out: list = []
        for item in raw:
            if isinstance(item, dict) and str(item.get("title", "")).strip():
                title = str(item["title"]).strip()[:30]
                sub = self._collect_mindmap_children(item.get("children"))
                node = {"title": title}
                if sub:
                    node["children"] = sub
                out.append(node)
            elif isinstance(item, str) and item.strip():
                out.append({"title": item.strip()[:30]})
        return out[:6]

    def _fallback_chat(self, history: list, user_message: str, subject: str = "", grade: str = "") -> str:
        """AI 离线时的教学顾问兜底：按意图匹配给出可落地、结构化的教学建议。"""
        subject = (subject or "").strip()
        grade = (grade or "").strip()
        msg = self._repair_text(user_message).strip()
        ctx_bits = []
        if subject:
            ctx_bits.append(subject)
        if grade:
            ctx_bits.append(grade)
        ctx = ("（" + "·".join(ctx_bits) + "）") if ctx_bits else ""
        offline_note = (
            "\n\n— 当前为离线知识模式（AI 云端未连通），以上为基于教学经验的通用建议；"
            "如需针对你具体班级、教材版本的个性化方案，请在 AI 服务恢复后再次提问。"
        )

        if any(k in msg for k in ["你好", "您好", "在吗", "谢谢", "感谢", "辛苦"]) and len(msg) <= 12:
            hi = "你好！我是智教助手，你的教学顾问与备课搭档。" + (f"已记录你的任教学段{ctx}。" if ctx else "")
            return (
                hi + "\n\n我可以帮你：备课与教学设计、知识点讲解思路、课堂活动与提问设计、"
                "学情诊断与分层教学、家校沟通、复习备考、课堂管理、学生动机激发等。\n\n"
                "直接告诉我你想解决的教学问题，例如：\n"
                "- \"如何讲清分数乘法的算理？\"\n"
                "- \"设计一节《草船借箭》的导入环节\"\n"
                "- \"班上两极分化严重怎么办？\"\n"
                "- \"家长群里如何回复投诉？\"" + offline_note
            )

        subj_resp = self._subject_advice(msg, subject, grade)
        if subj_resp:
            return subj_resp + offline_note

        if any(k in msg for k in ["备课", "教学设计", "教案", "教学环节", "教学目标", "怎么设计", "如何设计", "设计一节", "设计这节", "课时方案"]):
            return self._chat_lesson_prep(ctx) + offline_note
        if any(k in msg for k in ["怎么讲", "如何讲", "怎么解释", "如何解释", "讲清楚", "讲不清", "学生不懂", "听不懂", "理解不了", "突破难点", "重难点", "算理", "为什么这样", "原理"]):
            return self._chat_explain(ctx) + offline_note
        if any(k in msg for k in ["导入", "开场", "引入", "情境", "激发兴趣", "吸引"]):
            return self._chat_intro(ctx) + offline_note
        if any(k in msg for k in ["课堂活动", "互动活动", "小组活动", "合作学习", "游戏", "动手", "探究", "角色扮演", "情境表演"]):
            return self._chat_activity(ctx) + offline_note
        if any(k in msg for k in ["提问", "追问", "问题设计", "提问技巧", "课堂提问"]):
            return self._chat_questioning(ctx) + offline_note
        if any(k in msg for k in ["纪律", "管纪律", "课堂管理", "课堂常规", "调皮", "捣乱", "走神", "注意力", "不专心", "讲话", "吵闹", "坐不住"]):
            return self._chat_management(ctx) + offline_note
        if any(k in msg for k in ["学困生", "后进生", "学困", "待优生", "跟不上", "两极分化", "差距大", "分层", "差异化", "因材施教", "培优补差"]):
            return self._chat_differentiation(ctx) + offline_note
        if any(k in msg for k in ["家长", "家校", "家访", "家长会", "家长群", "沟通家长", "投诉"]):
            return self._chat_parents(ctx) + offline_note
        if any(k in msg for k in ["作业", "布置作业", "评价", "批改", "反馈", "形成性评价", "作业量", "作业设计"]):
            return self._chat_assessment(ctx) + offline_note
        if any(k in msg for k in ["不想学", "没兴趣", "没动力", "厌学", "积极性", "不想听", "敷衍", "内驱力", "学习动机"]):
            return self._chat_motivation(ctx) + offline_note
        if any(k in msg for k in ["复习", "备考", "期末", "期中", "考试", "复习课", "冲刺", "考点", "应试"]):
            return self._chat_review(ctx) + offline_note
        if any(k in msg for k in ["新教师", "新手", "刚入职", "实习", "第一次上课", "新老师", "刚上班"]):
            return self._chat_newteacher(ctx) + offline_note

        return self._chat_general(msg, ctx) + offline_note

    def _subject_advice(self, msg: str, subject: str, grade: str) -> str:
        """识别学科相关提问，返回学科特色建议；无匹配返回空串。"""
        is_math = any(k in msg for k in ["数学", "算理", "算式", "方程", "函数", "几何", "分数", "小数", "乘法", "除法", "加减法", "应用题"])
        is_chinese = any(k in msg for k in ["语文", "课文", "识字", "写字", "阅读理解", "作文", "古诗词", "古诗", "文言文", "拼音", "草船借箭", "荷塘月色"])
        is_english = any(k in msg for k in ["英语", "单词", "语法", "口语", "听力", "时态", "从句", "because"])
        is_physics = any(k in msg for k in ["物理", "力学", "电学", "电路", "牛顿", "压强", "浮力", "光学"])
        if is_math:
            return (
                "【数学教学建议】\n\n"
                "一、算理优于算法\n"
                "数学核心是让学生懂\"为什么\"，而非记\"怎么做\"。讲新运算先用实物/画图/数轴把算理可视化（如分数乘法用面积模型），再给法则。\n\n"
                "二、三讲三练结构\n"
                "- 讲例题（边讲边写思维过程）→ 练模仿题\n"
                "- 讲变式（改一个条件/数据）→ 练变式题\n"
                "- 讲错题（学生典型错误当反面教材）→ 练易错题\n\n"
                "三、让错误可见\n"
                "数学最怕假装会。多用板演、白板小测、手势即时暴露思维。错题不只对答案，让学生讲\"我当时怎么想的\"。\n\n"
                "四、应用题三部曲\n"
                "读题（圈关键信息）→ 画图/列表（文字转成关系）→ 列式（再算）。低年级卡第一步，高年级卡第二步。\n\n"
                "告诉我具体课题（如\"分数除法\"\"平行四边形面积\"），我给更细的活动设计。"
            )
        if is_chinese:
            return (
                "【语文教学建议】\n\n"
                "一、朗读是地基\n"
                "低中年级把朗读做扎实：教师范读→跟读→指名读→齐读，注意停顿、重音、语气。朗读到位，理解自然跟上。\n\n"
                "二、课文\"三问法\"\n"
                "- 写了什么？（整体感知）\n"
                "- 怎么写的？（品词析句、写法）\n"
                "- 为什么这样写？（情感、主旨）\n\n"
                "三、作文从\"有话写\"到\"写得好\"\n"
                "先解决没素材：多搞观察课、活动作文。再解决写不具体：训练动作分解（把\"他跑了\"拆成 5 个动作）。最后才润色文采。\n\n"
                "四、识字/字词\n"
                "字理识字（讲字源）、归类识字（同偏旁）、语境识字（放词句里记），比机械抄写有效。\n\n"
                "告诉我具体课文或课型，我给针对性设计。"
            )
        if is_english:
            return (
                "【英语教学建议】\n\n"
                "一、输入先行（i+1 原则）\n"
                "新语言点先大量听/看→理解，再要求说/写。用 TPR、图片、情境让学生先懂意思，不要一上来就机械跟读。\n\n"
                "二、词不离句，句不离境\n"
                "单词放进有意义的句子里记，句子放进情境里用。避免单词—中文翻译的孤立记忆，那样学生只会背不会用。\n\n"
                "三、PPP 模式\n"
                "Presentation（呈现）→ Practice（控制练习）→ Production（自由产出）。第三步最常被省略，却最关键——要给真实任务去用语言。\n\n"
                "四、让沉默期变短\n"
                "不爱开口的学生：先做非语言回应（指、选、画），再重复性输出（跟读），最后创造性输出。降低开口焦虑。\n\n"
                "告诉我具体单元/课型，我给细化方案。"
            )
        if is_physics:
            return (
                "【物理教学建议】\n\n"
                "一、实验是物理的灵魂\n"
                "能做实验绝不只讲实验。演示实验要让现象出乎意料（引发认知冲突），分组实验让每个人动手。器材不足用生活物品替代（矿泉水瓶测压强）。\n\n"
                "二、从现象到规律四步\n"
                "观察现象 → 提出问题 → 猜想/设计实验 → 得出规律。规律不要直接给，让学生发现。\n\n"
                "三、建模与数学化\n"
                "讲公式时一定讲清每个字母的物理意义和单位，强调公式是规律的语言，而非要背的符号。\n\n"
                "四、典型误区预防\n"
                "力与运动（惯性误解）、电流方向、浮力沉浮条件……把这些高频误区编成判断题课前测，对症讲解。"
            )
        return ""

    def _chat_lesson_prep(self, ctx: str) -> str:
        return (
            f"关于备课，建议你按\"目标—学情—活动—评价\"四步设计{ctx}：\n\n"
            "一、明确可检验的教学目标（最关键）\n"
            "用\"学生能做什么 + 什么条件下 + 达到什么程度\"来写。例：学生能在 5 分钟内独立完成 3 道两位数乘法，正确率≥80%。\n"
            "避免\"让学生理解…\"\"培养…能力\"这类无法检测的目标。一节课 2-3 个核心目标即可。\n\n"
            "二、诊断学情\n"
            "这节课学生已有什么基础？常见误区是什么？课前用 2 道前测题摸底，或翻看上节课作业的典型错误。\n\n"
            "三、设计主干活动（建议 3 环节）\n"
            "- 导入（3-5 分钟）：旧知、生活情境或认知冲突引入。\n"
            "- 新知建构（15-20 分钟）：不要直接给结论，设计让学生发现的活动——观察、操作、讨论、归纳。\n"
            "- 巩固迁移（10-15 分钟）：模仿→变式→应用，难度阶梯上升。\n\n"
            "四、嵌入评价（防止假装听懂）\n"
            "每个环节末尾设一个检测点：提问、小测、板演、同伴互评，让你随时知道学生学到哪了。\n\n"
            "时间提醒：教师讲授总时长控制在 15 分钟内，把时间还给学生练与思。\n\n"
            "告诉我具体课题和年级，我给完整的环节脚本与活动设计。"
        )

    def _chat_explain(self, ctx: str) -> str:
        return (
            f"讲清一个难点，核心是搭台阶 + 可视化 + 证伪误区{ctx}：\n\n"
            "一、先找到学生的卡点\n"
            "学生不懂通常卡在某一个具体环节，不是整体不懂。问自己：这个知识依赖哪个旧知？哪个概念是转折点？把卡点定位到最小单元。\n\n"
            "二、搭台阶（最近发展区）\n"
            "把难点拆成 3-4 个递进小问题，每个学生能答上来，最终自己推出结论。例：讲分数除法→先复习分数意义→再问除以一个数=乘它倒数为什么成立→用面积图验证。\n\n"
            "三、可视化（多通道呈现）\n"
            "能画图就画图，能摆实物就摆实物。抽象概念配具象表征（数轴、面积模型、流程图、表格），让学生看见关系。\n\n"
            "四、用错误反证（认知冲突）\n"
            "先抛一个看起来对其实是错的判断，让多数学生踩坑，再一起分析为什么错——比直接讲正确结论印象深 3 倍。\n\n"
            "五、让学生复述/教别人\n"
            "讲完别问懂了吗（学生都会点头），而让 1-2 个学生用自己的话复述，或讲给同桌听。能讲清楚才是真懂。\n\n"
            "把具体知识点告诉我，我帮你拆台阶、设计冲突问题。"
        )

    def _chat_intro(self, ctx: str) -> str:
        return (
            f"好的导入能在 3-5 分钟抓住学生，常用 5 种方式{ctx}：\n\n"
            "1. 情境导入：用学生熟悉的生活场景切入（买菜算账、校园事件、新闻热点），让知识有用。\n"
            "2. 冲突导入：抛一个反直觉的现象或问题（如：1千克铁和1千克棉花谁重？），引发好奇。\n"
            "3. 悬念导入：讲半截故事/留个谜，答案藏在今天的内容里。\n"
            "4. 旧知导入：从上节课内容自然延伸，温故知新。\n"
            "5. 操作导入：动手做个小实验/小游戏，身体先参与，注意力立刻集中。\n\n"
            "避坑：导入别超过 5 分钟，别为热闹而热闹——导入必须直接服务于本课目标。\n\n"
            "告诉我课题，我帮你设计 1-2 个具体导入脚本。"
        )

    def _chat_activity(self, ctx: str) -> str:
        return (
            f"设计有效课堂活动，关键是任务清晰 + 人人有事做 + 及时反馈{ctx}：\n\n"
            "常用活动类型\n"
            "- 小组讨论：4 人一组，问题要有争议性/开放性，讨论前给 1 分钟独立思考，避免搭便车。\n"
            "- 角色扮演：语文/英语/历史特别适合，提前给角色卡和台词框架。\n"
            "- 操作探究：数学/科学课用学具、实验，让学生做出结论。\n"
            "- 游戏竞赛：抢答、卡片配对、知识闯关，适合巩固环节，注意控制节奏。\n"
            "- 同伴互教：会的学生教不会的，教的人反而学得更深。\n\n"
            "让活动不失控的 3 个原则\n"
            "1. 活动前讲清规则和产出（讨论结束每组派代表说 1 条），黑板上挂任务。\n"
            "2. 活动中教师巡视、记录、点拨，不站在讲台。\n"
            "3. 活动后必须汇报/展示/点评，否则学生会觉得讨论了没用。\n\n"
            "告诉我学科和课型，我帮你设计一个具体活动。"
        )

    def _chat_questioning(self, ctx: str) -> str:
        return (
            f"高质量课堂提问，记住三秒原则 + 追问 + 全员应答{ctx}：\n\n"
            "一、提问前的设计\n"
            "备课时写下 3-5 个核心问题，分三类：\n"
            "- 记忆型（是什么）→ 唤醒旧知\n"
            "- 理解型（为什么/怎么说）→ 促思考\n"
            "- 应用/评价型（如果…会怎样/你同意吗）→ 促迁移\n"
            "一节好课，后两类要占多数。\n\n"
            "二、提问技巧\n"
            "- 先问后叫人：先抛问题，停 3-5 秒（让所有人想），再随机点名。\n"
            "- 追问：学生答完，追问你怎么想到的？还有别的可能吗？把思维引向深处。\n"
            "- 不轻易否定：错误答案也是资源，追问这个想法哪里有问题，让全班分析。\n"
            "- 全员应答：用白板、手势、答题卡、随机抽签，让每个学生被迫回应。\n\n"
            "避坑：别只问对不对/是不是；别一问完立刻自己答。\n\n"
            "把要讲的课题告诉我，我帮你设计一组阶梯式提问。"
        )

    def _chat_management(self, ctx: str) -> str:
        return (
            f"课堂纪律靠规则前置 + 节奏控制 + 关系先行，而非吼叫{ctx}：\n\n"
            "一、预防优于纠正\n"
            "- 开学第一周把课堂常规立清楚（举手发言、不插嘴、安静信号），坚持执行。\n"
            "- 用固定的安静信号（拍手节奏、举手倒数、手势），比喊安静有效。\n\n"
            "二、走神/讲话：用教学手段拉回，而非批评\n"
            "- 突然停顿 3 秒（全班会安静看你）。\n"
            "- 把走神学生的名字编进例题（假设小明买了 3 个本子…），温和提醒。\n"
            "- 走下讲台站到他旁边继续讲，距离本身就是管理。\n\n"
            "三、调皮/对抗：私下处理，保护自尊\n"
            "- 课堂上不当众发作（易激化），课后单独谈。\n"
            "- 谈话用我观察到…+ 我担心…+ 我希望…句式，而非指责。\n"
            "- 找到行为背后的需求（求关注？听不懂？家庭问题？），对症下药。\n\n"
            "四、根本：让课足够有趣 + 师生关系好\n"
            "纪律问题 80% 来自课堂太无聊或学生不喜欢老师。把课上精彩、多关心学生，纪律自然好转。\n\n"
            "具体场景（哪个年级、什么行为）告诉我，我给针对性策略。"
        )

    def _chat_differentiation(self, ctx: str) -> str:
        return (
            f"应对两极分化/学困生，核心是分层不减负、抓两头带中间{ctx}：\n\n"
            "一、分层不分班（课内分层）\n"
            "- 目标分层：同一节课，学困生只要达成基础目标，学优生有挑战任务。\n"
            "- 任务分层：布置 A（基础）/B（提高）/C（拓展）三档作业，学生选做或指定。\n"
            "- 提问分层：简单问题给学困生（建立信心），难题给学优生。\n\n"
            "二、补差要抓前置基础\n"
            "学困生卡住往往是旧知识漏洞，不是这节课听不懂。诊断他缺哪块基础，用课前 10 分钟或课后针对性补。\n\n"
            "三、同伴互助（最省力）\n"
            "小老师制：1 个学优生帮 1 个学困生，捆绑考核（两人都进步才表扬）。教的人学得更深，被教的人压力小、敢问。\n\n"
            "四、保护学困生自尊\n"
            "- 永远不当众羞辱（这么简单都不会是毒药）。\n"
            "- 抓住任何小进步公开表扬，建立我能学的信念。\n"
            "- 错题私下反馈，不公布排名。\n\n"
            "五、培优要给空间\n"
            "学优生最怕吃不饱被打发。给自主探究任务、当小老师、参加竞赛，让能量有出口。\n\n"
            "具体学科和年级告诉我，我帮你设计分层任务清单。"
        )

    def _chat_parents(self, ctx: str) -> str:
        return (
            f"家校沟通关键是先共情 + 讲事实 + 给方案，而非告状{ctx}：\n\n"
            "一、沟通前心态\n"
            "家长不是对手，是同盟。即使投诉的家长，本质也是为孩子好。先听他说完，别急着辩解。\n\n"
            "二、报问题的标准话术（三明治法）\n"
            "1. 先说一个孩子的优点/进步（让家长放下防备）。\n"
            "2. 客观陈述问题（只讲事实，不带评价：最近三次作业有两次没交，而非这孩子太懒）。\n"
            "3. 表达关心 + 给具体方案（我担心影响他后续学习，咱们一起想想办法，我建议…您看行吗？）。\n\n"
            "三、家长群沟通禁忌\n"
            "- 不在群里点名批评个别学生（保护隐私）。\n"
            "- 不在群里跟家长争论（私聊处理）。\n"
            "- 通知类信息简洁清晰，避免长语音。\n"
            "- 投诉先回应已收到，X 点前给您答复，别晾着。\n\n"
            "四、家访/约谈\n"
            "- 提前预约，不突袭。\n"
            "- 先表扬再谈问题，结束时达成 1-2 个可执行小目标。\n"
            "- 记录谈话要点，下次跟进。\n\n"
            "具体场景（投诉什么/孩子什么问题）告诉我，我帮你写一段沟通话术。"
        )

    def _chat_assessment(self, ctx: str) -> str:
        return (
            f"作业与评价的核心是少而精 + 即时反馈 + 促学而非排名{ctx}：\n\n"
            "一、作业设计原则\n"
            "- 少而精：3 道有思维含量的题 > 30 道机械重复。\n"
            "- 分层：基础题全员必做，挑战题选做，避免学困生抄、学优生闲。\n"
            "- 形式多样：除书面外，加口头、实践、项目作业（如用本周学的统计调查家里一周用电量）。\n"
            "- 必批必改必反馈：不批的作业等于没布置；批改后要讲评典型错题。\n\n"
            "二、形成性评价（重过程）\n"
            "不只看期末考试。日常用：课堂提问记录、小测、作品集、同伴互评，让评价贯穿学习全过程。\n\n"
            "三、反馈的艺术\n"
            "- 具体：第二步符号写反了 > 粗心。\n"
            "- 可改进：指出下一步怎么做，而非只判对错。\n"
            "- 及时：当天/次日反馈，隔一周就失效。\n"
            "- 成长导向：比上次进步了比 85 分更有激励作用。\n\n"
            "具体学科和题型告诉我，我帮你设计一份分层作业。"
        )

    def _chat_motivation(self, ctx: str) -> str:
        return (
            f"激发学习动机，从胜任感 + 自主感 + 归属感入手{ctx}：\n\n"
            "一、胜任感：让他尝到成功的甜头\n"
            "没兴趣的学生，往往因为长期学不会而放弃。给他够得着的小目标，让他体验我会了——一次小测进步、一道题做对，立刻肯定。信心是兴趣的前提。\n\n"
            "二、自主感：给他选择权\n"
            "人对被命令的事天然抗拒。给有限选择：今天作业 A 还是 B？小组讨论你想当记录员还是汇报员？参与感提升投入度。\n\n"
            "三、归属感：让他感到被看见\n"
            "记住每个学生的名字和一件小事，课堂上让每个人都有发言机会。学生因为喜欢这个老师而喜欢这门课是真实存在的。\n\n"
            "四、让知识有用 + 有趣\n"
            "- 联系生活/热点/学生关心的事，让知识活起来。\n"
            "- 用游戏、竞赛、悬念，让过程有乐趣。\n"
            "- 慎用外在奖励：物质奖励/加分短期有效，长期会削弱内驱力。多用成长反馈、公开认可。\n\n"
            "五、排查外部原因\n"
            "突然厌学，先了解：家庭变故？同伴关系？沉迷手机？身体/心理问题？对症才能解。\n\n"
            "具体是哪个学生/什么表现告诉我，我给针对性方案。"
        )

    def _chat_review(self, ctx: str) -> str:
        return (
            f"复习备考要结构化 + 错题驱动 + 模拟实战，而非题海{ctx}：\n\n"
            "一、先建知识结构（脑图）\n"
            "复习不是把新课重讲一遍。先带学生画整章/整册知识脑图，理清脉络，让零散知识串成网。结构清晰，提取才快。\n\n"
            "二、错题驱动（最高效）\n"
            "把全学期高频错题/易错点整理成专题，针对性突破。会的题不重复刷，时间留给真问题。建议每个学生建错题本，定期重做。\n\n"
            "三、三轮复习节奏\n"
            "- 第一轮：单元过关，扫清知识盲点（重基础）。\n"
            "- 第二轮：专题整合，跨章节串联（重综合）。\n"
            "- 第三轮：模拟实战，限时训练（重应试与心态）。\n\n"
            "四、模拟考试要仿真\n"
            "限时、独立、评分标准对齐正式考试。考后不只对答案，要分析：哪类题失分？知识漏洞还是应试失误？制定针对性补救。\n\n"
            "五、别忘了心态\n"
            "考前焦虑的学生很多。适当减压，强调尽力就好，别把分数和人格绑定。\n\n"
            "具体学科和学段告诉我，我帮你列复习专题清单。"
        )

    def _chat_newteacher(self, ctx: str) -> str:
        return (
            f"新手教师上路，先稳住课堂 + 关系 + 心态三件事{ctx}：\n\n"
            "一、第一年别追求花哨，先求稳\n"
            "- 把常规立住（纪律、作业、发言规则），课堂乱什么都做不好。\n"
            "- 备课写详案（每环节说什么、问什么、学生可能怎么答），别只写框架。\n"
            "- 多听老教师的课，模仿是最好的学习。\n\n"
            "二、师生关系：严慈相济\n"
            "- 开学先立威（规则严、说到做到），再慢慢施恩（关心、幽默、认可）。顺序反了很难管。\n"
            "- 记住每个学生名字，课后多聊天。被看见的学生才会配合你。\n"
            "- 永远不当众发火/羞辱学生，一次就可能毁掉整学期关系。\n\n"
            "三、教学：少讲多练，别贪多\n"
            "- 一节课 2-3 个核心点足够，讲透练透比走马观花强。\n"
            "- 教师讲授控制在 15 分钟内，剩下时间给学生。\n"
            "- 每节课留 5 分钟检测，知道自己教得怎么样。\n\n"
            "四、心态：别和名师比，和自己比\n"
            "- 第一年上不好很正常，三年才成型，五年才出风格。\n"
            "- 别把所有问题归咎于自己（学生基础、家庭都是变量）。\n"
            "- 找一个愿意带你/听你课的师傅，成长快 3 倍。\n\n"
            "具体困惑（管不住班？备课没底？家长沟通？）告诉我，我针对性支招。"
        )

    def _chat_general(self, msg: str, ctx: str) -> str:
        return (
            f"我收到了你的问题。为了让建议更精准，先按问题—对象—目标帮你理一理{ctx}：\n\n"
            "一、你想解决的核心问题是什么？\n"
            "比如：备课没思路？某个知识点学生听不懂？课堂纪律乱？学生没兴趣？家长难沟通？复习效率低？\n\n"
            "二、针对的对象和情境？\n"
            "学科、年级、班级特点（人数、两极分化程度）、这节课/这个学生的具体情况。\n\n"
            "三、你期望达成的目标？\n"
            "想要一份完整教案？一个活动设计？一段沟通话术？一个分层作业？还是某个具体问题的解决思路？\n\n"
            "把这些信息补充给我，我能给出可直接用的方案。你也可以直接试试这些常见问题：\n"
            "- 如何讲清[某知识点]？\n"
            "- 设计一节[某课题]的导入/活动\n"
            "- 班上两极分化怎么办？\n"
            "- 学生上课走神怎么管理？\n"
            "- 如何回复家长的投诉？"
        )

    def _fallback_mindmap(self, topic: str, subject: str) -> dict:
        topic = self._repair_text(topic)
        title = topic[:24] or "思维导图"
        for keys, nodes in self._mindmap_kb():
            if any(k in topic for k in keys):
                return {"title": title, "nodes": nodes}
        return {"title": title, "nodes": self._mindmap_subject_template(subject)}

    # ---- 主题感知思维导图知识库 ----
    _MM_COLORS = ["#00a870", "#2563eb", "#d97706", "#db2777", "#7c3aed", "#0891b2"]

    def _mm_nodes(self, *branches):
        out = []
        for i, (title, kids) in enumerate(branches):
            out.append({"title": title, "color": self._MM_COLORS[i % len(self._MM_COLORS)],
                        "children": [{"title": k} for k in kids]})
        return out

    def _mindmap_kb(self):
        mm = self._mm_nodes
        # 历史
        if False:
            pass
        kb = [
            (["朝代", "历代", "王朝", "中国古代史"], mm(
                ("先秦文明", ["夏商周更替", "春秋五霸", "战国七雄"]),
                ("秦汉大一统", ["秦始皇统一", "汉武帝强盛", "丝绸之路"]),
                ("隋唐盛世", ["隋朝开科", "贞观之治", "开元盛世"]),
                ("宋元变革", ["宋代理学", "元朝行省制", "四大发明"]),
            )),
            (["丝绸之路"], mm(
                ("陆上丝路", ["张骞出使西域", "长安出发", "途经河西走廊"]),
                ("海上丝路", ["泉州广州港口", "瓷器丝绸外销", "郑和下西洋"]),
                ("贸易商品", ["丝绸", "瓷器", "茶叶", "香料"]),
                ("文化交流", ["佛教东传", "四大发明西传", "中外互通"]),
            )),
            (["工业革命"], mm(
                ("第一次工业革命", ["蒸汽机", "纺织业机械化", "铁路交通"]),
                ("第二次工业革命", ["电力", "内燃机", "化学工业"]),
                ("社会影响", ["城市化", "阶级变化", "殖民扩张"]),
                ("科技进步", ["生产力飞跃", "世界市场形成", "环境污染"]),
            )),
            (["抗日战争", "抗战"], mm(
                ("局部抗战", ["九一八事变", "东北沦陷", "义勇军抗争"]),
                ("全面抗战", ["七七事变", "正面战场", "敌后战场"]),
                ("重大战役", ["台儿庄", "百团大战", "平型关"]),
                ("伟大胜利", ["统一战线", "世界反法西斯", "日本投降"]),
            )),
            (["文艺复兴"], mm(
                ("兴起背景", ["意大利城邦", "资本主义萌芽", "人文主义"]),
                ("代表人物", ["但丁", "达芬奇", "莎士比亚"]),
                ("核心思想", ["以人为本", "个性解放", "反对神权"]),
                ("深远影响", ["思想解放", "科学革命", "宗教改革"]),
            )),
            (["辛亥革命"], mm(
                ("革命背景", ["清末危机", "民族资本主义", "革命思想传播"]),
                ("革命过程", ["武昌起义", "各省响应", "建立民国"]),
                ("历史意义", ["推翻帝制", "民主共和", "思想解放"]),
                ("局限性", ["革命不彻底", "军阀割据", "任务未完成"]),
            )),
            # 地理
            (["气候", "气候类型", "气温降水"], mm(
                ("影响因子", ["纬度", "海陆", "地形", "洋流"]),
                ("主要类型", ["热带雨林", "季风气候", "温带大陆性", "地中海气候"]),
                ("降水规律", ["赤道多雨", "副热带少雨", "温带增多"]),
                ("中国气候", ["季风显著", "雨热同期", "气候复杂多样"]),
            )),
            (["地形", "地貌", "地势"], mm(
                ("基本地形", ["山地", "平原", "高原", "盆地", "丘陵"]),
                ("中国地势", ["西高东低", "阶梯分布", "大河东流"]),
                ("外力作用", ["流水侵蚀", "风力沉积", "冰川作用"]),
                ("典型地貌", ["喀斯特", "丹霞", "黄土高原", "冲积平原"]),
            )),
            (["河流", "水系", "长江", "黄河"], mm(
                ("长江", ["发源青藏", "流经十一省", "入东海", "黄金水道"]),
                ("黄河", ["发源巴颜喀拉", "泥沙含量大", "地上河", "入渤海"]),
                ("河流作用", ["供水灌溉", "航运发电", "塑造平原"]),
                ("治理保护", ["防洪堤坝", "水土保持", "生态修复"]),
            )),
            (["地球", "地球运动", "自转公转"], mm(
                ("自转", ["绕轴旋转", "昼夜交替", "时差"]),
                ("公转", ["绕日运行", "四季更替", "五带划分"]),
                ("黄赤交角", ["23.5度", "太阳直射点移动", "昼夜长短变化"]),
                ("地理意义", ["正午太阳高度", "节气", "气候形成"]),
            )),
            # 生物
            (["细胞"], mm(
                ("细胞结构", ["细胞膜", "细胞质", "细胞核", "细胞壁(植物)"]),
                ("细胞器", ["线粒体", "叶绿体", "核糖体", "液泡"]),
                ("细胞分裂", ["有丝分裂", "减数分裂", "无丝分裂"]),
                ("细胞分化", ["形态变化", "功能特化", "形成组织"]),
            )),
            (["光合作用"], mm(
                ("反应条件", ["光照", "叶绿体", "适宜温度"]),
                ("原料产物", ["二氧化碳", "水", "氧气", "有机物"]),
                ("两个阶段", ["光反应", "暗反应", "能量转化"]),
                ("重要意义", ["制造有机物", "释放氧气", "碳氧平衡"]),
            )),
            (["生态系统"], mm(
                ("组成成分", ["非生物物质", "生产者", "消费者", "分解者"]),
                ("食物链网", ["捕食关系", "能量单向", "物质循环"]),
                ("能量流动", ["太阳能输入", "逐级递减", "10%-20%传递"]),
                ("生态平衡", ["自我调节", "稳定性", "人类影响"]),
            )),
            (["遗传", "基因", "DNA"], mm(
                ("遗传物质", ["DNA", "基因", "染色体"]),
                ("基本规律", ["分离定律", "自由组合", "显隐性"]),
                ("遗传变异", ["基因突变", "基因重组", "染色体变异"]),
                ("应用拓展", ["育种", "遗传咨询", "基因工程"]),
            )),
            (["人体", "消化", "呼吸", "循环"], mm(
                ("消化系统", ["口腔胃小肠", "消化酶", "吸收营养"]),
                ("呼吸系统", ["呼吸道", "肺泡", "气体交换"]),
                ("循环系统", ["心脏", "血管", "血液循环"]),
                ("神经系统", ["大脑", "神经传导", "反射调节"]),
            )),
            # 化学
            (["元素周期表", "元素"], mm(
                ("结构规律", ["周期", "族", "原子序数", "递变规律"]),
                ("主族元素", ["碱金属", "卤素", "氧族", "氮族"]),
                ("周期变化", ["原子半径递减", "金属性减弱", "非金属性增强"]),
                ("应用价值", ["预测性质", "寻找新材料", "指导分类"]),
            )),
            (["化学反应"], mm(
                ("反应类型", ["化合", "分解", "置换", "复分解"]),
                ("反应条件", ["加热", "点燃", "催化", "通电"]),
                ("能量变化", ["放热反应", "吸热反应", "化学能转化"]),
                ("方程式", ["质量守恒", "配平", "符号规范"]),
            )),
            (["酸碱盐", "酸碱"], mm(
                ("常见酸", ["盐酸", "硫酸", "硝酸", "醋酸"]),
                ("常见碱", ["氢氧化钠", "氢氧化钙", "氨水"]),
                ("酸碱反应", ["中和反应", "生成盐和水", "pH变化"]),
                ("盐的性质", ["溶解性", "复分解", "焰色反应"]),
            )),
            (["原子", "分子", "物质构成"], mm(
                ("原子结构", ["原子核", "质子", "中子", "核外电子"]),
                ("分子构成", ["共价键", "分子间作用力", "分子特性"]),
                ("离子化合物", ["得失电子", "离子键", "晶体结构"]),
                ("物质分类", ["单质", "化合物", "混合物"]),
            )),
            # 物理
            (["力学", "力", "牛顿"], mm(
                ("常见的力", ["重力", "弹力", "摩擦力", "浮力"]),
                ("牛顿三定律", ["惯性定律", "加速度定律", "作用反作用"]),
                ("压强", ["固体压强", "液体压强", "大气压强"]),
                ("简单机械", ["杠杆", "滑轮", "斜面", "功的原理"]),
            )),
            (["电学", "电流", "电路", "欧姆"], mm(
                ("基本物理量", ["电流", "电压", "电阻", "电功率"]),
                ("欧姆定律", ["I=U/R", "串并联电阻", "电压电流关系"]),
                ("电路连接", ["串联", "并联", "混联", "短路断路"]),
                ("电与磁", ["电流磁效应", "电磁感应", "电动机发电机"]),
            )),
            (["光学", "光", "反射折射"], mm(
                ("光的传播", ["直线传播", "光速", "影子小孔成像"]),
                ("光的反射", ["反射定律", "镜面反射", "漫反射"]),
                ("光的折射", ["折射定律", "全反射", "色散"]),
                ("透镜成像", ["凸透镜", "凹透镜", "成像规律", "应用"]),
            )),
            (["运动", "速度", "加速度"], mm(
                ("运动描述", ["参照物", "路程位移", "速度"]),
                ("匀速运动", ["速度恒定", "s=vt", "图像分析"]),
                ("变速运动", ["加速度", "v=v0+at", "匀变速直线"]),
                ("相对运动", ["相对速度", "相遇追及", "实际应用"]),
            )),
            # 数学
            (["函数"], mm(
                ("函数概念", ["定义域", "值域", "对应关系"]),
                ("基本初等函数", ["一次函数", "二次函数", "反比例函数"]),
                ("指数对数", ["指数函数", "对数函数", "运算法则"]),
                ("函数性质", ["单调性", "奇偶性", "周期性"]),
            )),
            (["几何", "三角形", "圆"], mm(
                ("线与角", ["点线面", "相交平行", "角的关系"]),
                ("三角形", ["内角和", "全等相似", "勾股定理"]),
                ("四边形", ["平行四边形", "矩形菱形", "梯形"]),
                ("圆", ["圆的性质", "切线", "弧长扇形"]),
            )),
            (["方程", "一元", "二元", "不等式"], mm(
                ("一元一次", ["等式性质", "求解步骤", "应用题"]),
                ("方程组", ["二元一次", "代入消元", "加减消元"]),
                ("一元二次", ["因式分解", "公式法", "韦达定理"]),
                ("不等式", ["性质", "一元一次不等式", "不等式组"]),
            )),
            (["概率", "统计"], mm(
                ("数据收集", ["普查抽样", "频数频率", "统计图表"]),
                ("数据特征", ["平均数", "中位数众数", "方差极差"]),
                ("概率初步", ["事件分类", "古典概型", "频率估计", "树状图列举"]),
                ("应用", ["决策分析", "风险评估", "生活实例"]),
            )),
            # 语文
            (["古诗", "古诗词", "唐诗宋词"], mm(
                ("发展脉络", ["诗经楚辞", "唐诗", "宋词", "元曲"]),
                ("代表诗人", ["李白杜甫", "白居易", "苏轼李清照"]),
                ("常见题材", ["山水田园", "边塞", "咏物言志", "送别"]),
                ("鉴赏方法", ["意象意境", "表现手法", "炼字", "情感主旨"]),
            )),
            (["记叙文"], mm(
                ("六要素", ["时间地点", "人物", "起因经过结果"]),
                ("结构层次", ["开头引入", "主体展开", "结尾点题"]),
                ("表达方式", ["叙述", "描写", "议论抒情"]),
                ("写作技巧", ["详略得当", "线索贯穿", "细节描写"]),
            )),
            (["议论文"], mm(
                ("三要素", ["论点", "论据", "论证"]),
                ("论点确立", ["中心论点", "分论点", "鲜明准确"]),
                ("论证方法", ["举例论证", "道理论证", "对比比喻"]),
                ("结构思路", ["提出问题", "分析问题", "解决问题"]),
            )),
            # 英语
            (["时态"], mm(
                ("一般时态", ["一般现在", "一般过去", "一般将来"]),
                ("进行时", ["现在进行", "过去进行", "be+doing"]),
                ("完成时", ["现在完成", "过去完成", "have+done"]),
                ("时间状语", ["always/often", "yesterday", "already/yet"]),
            )),
            (["从句"], mm(
                ("名词性从句", ["主语从句", "宾语从句", "表语从句"]),
                ("定语从句", ["关系代词", "关系副词", "限制非限制"]),
                ("状语从句", ["时间原因", "条件让步", "目的结果"]),
                ("用法要点", ["连接词", "语序", "时态呼应"]),
            )),
        ]
        return kb

    def _mindmap_subject_template(self, subject: str) -> list:
        subject = (subject or "").strip()
        mm = self._mm_nodes
        templates = {
            "数学": mm(
                ("概念理解", ["定义", "性质", "判定条件"]),
                ("公式法则", ["基本公式", "运算法则", "推导过程"]),
                ("典型例题", ["基础题", "应用题", "易错题"]),
                ("知识应用", ["实际问题", "跨学科", "拓展提升"]),
            ),
            "物理": mm(
                ("物理概念", ["定义", "物理意义", "单位"]),
                ("规律定律", ["适用条件", "公式表达", "实验基础"]),
                ("实验探究", ["实验器材", "操作步骤", "数据处理"]),
                ("生活应用", ["现象解释", "技术应用", "综合计算"]),
            ),
            "化学": mm(
                ("物质组成", ["元素", "结构", "性质"]),
                ("变化规律", ["反应类型", "反应条件", "实验现象"]),
                ("化学计算", ["化学式", "方程式", "质量计算"]),
                ("实际应用", ["材料能源", "环境保护", "生命健康"]),
            ),
            "生物": mm(
                ("生命现象", ["结构基础", "生理功能", "生命活动"]),
                ("核心概念", ["定义", "原理", "机制"]),
                ("实验观察", ["方法", "现象", "结论"]),
                ("联系应用", ["生产实践", "健康生活", "生态保护"]),
            ),
            "历史": mm(
                ("时代背景", ["政治", "经济", "文化"]),
                ("重要事件", ["时间", "人物", "过程"]),
                ("深远影响", ["制度变革", "思想文化", "社会发展"]),
                ("历史启示", ["经验教训", "规律认识", "现实意义"]),
            ),
            "地理": mm(
                ("空间分布", ["位置", "范围", "界线"]),
                ("自然要素", ["地形气候", "水文土壤", "植被"]),
                ("人文要素", ["人口城市", "农业工业", "交通"]),
                ("人地关系", ["资源利用", "环境问题", "可持续发展"]),
            ),
            "语文": mm(
                ("基础知识", ["字词", "语句", "修辞"]),
                ("文本理解", ["内容", "结构", "主旨"]),
                ("表达技巧", ["描写方法", "表现手法", "语言特色"]),
                ("拓展运用", ["写作借鉴", "迁移阅读", "文化传承"]),
            ),
            "英语": mm(
                ("词汇积累", ["核心单词", "短语搭配", "词形变化"]),
                ("语法要点", ["句型结构", "时态语态", "从句"]),
                ("功能话题", ["日常交际", "话题表达", "文化背景"]),
                ("技能训练", ["听说", "读写", "综合运用"]),
            ),
        }
        if subject in templates:
            return templates[subject]
        return mm(
            ("核心概念", ["定义", "特征", "分类"]),
            ("知识结构", ["基本原理", "重要规律", "内在联系"]),
            ("重点方法", ["解题思路", "分析方法", "易错提示"]),
            ("应用拓展", ["生活实例", "学科关联", "拓展提升"]),
        )


    async def generate_animation(self, prompt: str, anim_type: str = "general") -> dict:
        prompt = self._repair_text(prompt)
        system_prompt = f"""你是一位教学动画设计专家。根据教师描述，生成教学动画的HTML页面。

重要规则：
- 所有HTML属性必须用单引号，如 style='color:red;' onclick='fn()'
- 不要使用<script>、Canvas或外部资源，优先用纯CSS动画、SVG和HTML元素实现
- 不要使用vh/vw单位，用px或%
- HTML从<div>开始，不含<html><head><body>
- 容器设置 style='width:100%;height:100%;position:relative;overflow:hidden;'
- 代码尽量精简，避免过长的内联样式

设计要求：
- 使用CSS keyframes或SVG animate实现教学动画效果
- 视觉风格要像教师备课平台的课堂白板：浅色背景、绿色主色（#00a870 / #0f766e）、白色内容舞台、细边框、柔和阴影
- 不要使用深色科幻背景、霓虹光效、大面积高饱和渐变；动画应清爽、可信、适合课堂投屏
- 配色克制，动画流畅，重点元素可以用少量橙色/蓝色强调
- 必须有成熟产品质感：顶部信息栏、白色主舞台、圆角、细边框、柔和投影、右侧知识卡或底部步骤进度
- 视觉不能像临时demo，不能只有几个漂浮圆点；图形必须承载知识含义
- 包含和教师输入主题直接相关的图形、标注、步骤和说明
- 可以使用伪播放控件样式，但不要依赖JavaScript控制逻辑
- 包含文字标注和说明
- 动画类型: {anim_type}

直接输出JSON（不要markdown代码块，不要其他文字）：
{{"title":"动画标题","description":"动画说明","html":"HTML代码字符串","scenes":[{{"id":1,"name":"场景名","duration":3,"narration":"旁白"}}],"totalDuration":15,"interactive":true}}"""
        try:
            result = await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": prompt},
            ], temperature=0.5, max_tokens=16384)
            return self._normalize_animation_result(result, prompt, anim_type)
        except RuntimeError:
            return self._fallback_animation(prompt, anim_type)

    def _normalize_animation_result(self, result: dict, prompt: str, anim_type: str) -> dict:
        prompt = self._repair_text(prompt)
        html = result.get("html")
        if not isinstance(html, str):
            return self._fallback_animation(prompt, anim_type)

        cleaned = html.strip()
        # The preview iframe must never show a "successful" blank result. Canvas/script
        # animations from the model are often syntactically invalid or depend on brittle
        # globals, so prefer the stable CSS animation fallback in that case.
        if (
            len(cleaned) < 160
            or "<div" not in cleaned.lower()
            or re.search(r"<script\b|<canvas\b", cleaned, re.IGNORECASE)
            or re.search(r"display\s*:\s*none|opacity\s*:\s*0\b|height\s*:\s*0\b", cleaned, re.IGNORECASE)
        ):
            return self._fallback_animation(prompt, anim_type)

        if not re.search(r"animation|@keyframes|svg|style", cleaned, re.IGNORECASE):
            return self._fallback_animation(prompt, anim_type)

        if not self._animation_matches_prompt(prompt, cleaned, result):
            return self._fallback_animation(prompt, anim_type)

        if not self._animation_has_quality(cleaned):
            return self._fallback_animation(prompt, anim_type)

        result["html"] = cleaned.replace("100vh", "100%").replace("100vw", "100%")
        result.setdefault("title", prompt[:24] or "教学动画")
        result.setdefault("description", f"{anim_type} 教学动画")
        result.setdefault("scenes", [{"id": 1, "name": "演示", "duration": 8, "narration": "观察动画变化"}])
        result.setdefault("totalDuration", 8)
        result.setdefault("interactive", True)
        return result

    def _animation_category(self, prompt: str) -> str:
        prompt = self._repair_text(prompt)
        prompt_lower = prompt.lower()
        if any(k in prompt for k in ["圆柱", "体积", "π", "半径", "底面积"]):
            return "cylinder"
        if any(k in prompt for k in ["函数", "抛物线", "二次", "坐标", "图像", "y="]) or any(k in prompt_lower for k in ["function", "parabola", "quadratic", "axis"]):
            return "function"
        if any(k in prompt for k in ["光合", "叶绿体", "植物", "二氧化碳", "氧气"]):
            return "photosynthesis"
        if any(k in prompt for k in ["化学", "反应", "分子", "原子", "方程式", "燃烧"]):
            return "chemistry"
        if any(k in prompt for k in ["地球", "公转", "自转", "四季", "太阳"]):
            return "orbit"
        if any(k in prompt for k in ["力", "速度", "运动", "加速度", "物理", "斜面"]):
            return "motion"
        if any(k in prompt for k in ["三角形", "内角和", "内角", "勾股", "直角", "锐角", "钝角", "几何", "角度", "全等", "相似", "多边形", "梯形", "平行四边", "矩形", "正方形", "长方形", "圆面积", "圆的面积", "圆周长", "圆周率", "顶角", "底角", "平角", "周角"]):
            return "geometry"
        return "general"

    def _animation_matches_prompt(self, prompt: str, html: str, result: dict) -> bool:
        prompt = self._repair_text(prompt)
        category = self._animation_category(prompt)
        if category == "general":
            return True

        text = html.lower().replace(prompt.lower(), "")
        markers = {
            "cylinder": ["圆柱", "体积", "π", "半径", "底面积", "v ="],
            "function": ["函数", "抛物线", "坐标", "y =", "ax", "curve"],
            "photosynthesis": ["光合", "叶绿体", "植物", "co₂", "co2", "氧气", "o₂", "o2"],
            "chemistry": ["化学", "反应", "分子", "原子", "方程式", "生成物"],
            "orbit": ["地球", "公转", "自转", "四季", "太阳", "orbit"],
            "motion": ["速度", "运动", "加速度", "物理", "力", "vector"],
            "geometry": ["三角形", "内角", "勾股", "几何", "角度", "全等", "相似", "多边形", "180", "圆面积", "圆周长", "∠"],
        }
        return any(marker.lower() in text for marker in markers.get(category, []))

    def _animation_has_quality(self, html: str) -> bool:
        text = html.lower()
        if any(bad in text for bad in ["#020617", "#111827", "#0a1628", "neon", "霓虹"]):
            return False
        required = ["border-radius", "box-shadow"]
        if not all(token in text for token in required):
            return False
        has_light_stage = any(token in text for token in ["background:#fff", "background: #fff", "background:white", "background: white"])
        has_platform_green = any(token in text for token in ["#00a870", "#0f766e", "#00543d", "#10b981"])
        return has_light_stage and has_platform_green

    def _repair_text(self, value: str) -> str:
        if not isinstance(value, str):
            return ""
        # Some Windows clients send UTF-8 text that has been decoded as Latin-1.
        # Repair that common mojibake shape before keyword matching.
        if any(ch in value for ch in ["å", "ç", "æ", "è", "é"]):
            try:
                repaired = value.encode("latin1").decode("utf-8")
                if repaired and repaired != value:
                    return repaired
            except UnicodeError:
                pass
        return value

    async def generate_exercise(self, prompt: str, exercise_type: str = "choice",
                                subject: str = "", knowledge_points: list = None,
                                count: int = 5) -> dict:
        kp_str = "、".join(knowledge_points) if knowledge_points else "未指定"
        system_prompt = f"""你是一位教学练习设计专家。生成{exercise_type}类型的练习题。

知识点：{kp_str}
学科：{subject or '未指定'}
题目数量：{count}

每道题目需要生成一个可以直接在浏览器渲染的HTML互动组件。
- 选择题：显示选项按钮，点击后高亮显示对错
- 填空题：显示输入框和提交按钮
- 判断题：显示对/错按钮
- HTML片段不要包含<html><head><body>标签，直接从<div>开始
- 不要使用vh/vw单位，使用px或%代替

输出JSON：
{{
  "title": "练习标题",
  "questions": [
    {{
      "id": 1,
      "type": "choice|fill_blank|true_false|matching",
      "question": "题干文本",
      "options": ["A选项", "B选项", "C选项", "D选项"],
      "answer": "正确答案",
      "explanation": "详细解析",
      "difficulty": "easy|medium|hard",
      "html": "该题目的完整HTML互动代码"
    }}
  ]
}}"""
        try:
            return await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": prompt},
            ], temperature=0.5, max_tokens=8192)
        except RuntimeError:
            return self._fallback_exercise(prompt, exercise_type, subject, knowledge_points, count)

    async def generate_lesson_plan(self, title: str, subject: str = "", grade: str = "",
                                   objectives: list = None, duration: int = 45,
                                   extra_requirements: str = "") -> dict:
        obj_str = "\n".join(f"- {o}" for o in (objectives or []))
        system_prompt = """你是一位资深教学设计专家。根据教师需求生成完整的教案。

教案内容要详实、可操作，每个环节的具体活动描述不少于50字。

输出JSON格式：
{
  "title": "教案标题",
  "objectives": ["教学目标1（具体可衡量的描述）", "教学目标2"],
  "key_points": ["教学重点1（说明为什么是重点）"],
  "difficulties": ["教学难点1（说明突破策略）"],
  "phases": [
    {
      "name": "导入/新授/练习/巩固/总结",
      "duration": 5,
      "activities": ["活动1：具体描述活动内容和步骤", "活动2：具体描述"],
      "teacher_actions": ["教师具体行为描述", "教师提问的问题"],
      "student_actions": ["预期学生行为和回答", "学生参与方式"],
      "resources": ["所需教具和材料"]
    }
  ],
  "homework": ["作业1：具体题目或任务描述"],
  "reflection": "教学反思提示"
}"""
        user_msg = f"课题：{title}\n学科：{subject}\n年级：{grade}\n时长：{duration}分钟\n教学目标：\n{obj_str}\n附加要求：{extra_requirements}"
        try:
            return await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": user_msg},
            ])
        except RuntimeError:
            return self._fallback_lesson_plan(title, subject, grade, objectives, duration)

    async def grade_essay(self, essay_text: str, grade_level: str = "初中",
                          essay_type: str = "记叙文", total_score: int = 50) -> dict:
        system_prompt = f"""你是一位资深的语文作文批改专家。请对以下作文进行全面批改。

年级段：{grade_level}
作文类型：{essay_type}
满分：{total_score}分

评分维度及权重：
- 内容与立意 (30%)
- 结构与条理 (25%)
- 语言表达 (25%)
- 书写与规范 (20%)

批改要求：
1. 逐段给出具体评语
2. 指出好词好句并说明为什么好
3. 指出具体问题并给出修改建议
4. 总评要结合年级段要求来评价

输出JSON：
{{
  "total_score": 38,
  "scores": {{
    "content": {{"score": 25, "max": 30, "comment": "具体评语"}},
    "structure": {{"score": 20, "max": 25, "comment": "具体评语"}},
    "language": {{"score": 18, "max": 25, "comment": "具体评语"}},
    "writing": {{"score": 15, "max": 20, "comment": "具体评语"}}
  }},
  "overall_comment": "总评（100字以上详细评语）",
  "strengths": ["优点1（引用原文并分析）"],
  "weaknesses": ["不足1（引用原文并给出修改）"],
  "suggestions": ["改进建议1（具体可操作的建议）"],
  "annotations": [
    {{"text": "原文片段", "comment": "批注", "type": "error|good|suggestion"}}
  ],
  "level": "优秀|良好|中等|及格|不及格"
}}"""
        try:
            return await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": essay_text},
            ])
        except RuntimeError:
            return self._fallback_essay_grade(essay_text, total_score)

    async def generate_exam(self, subject: str, grade: str = "", knowledge_points: list = None,
                            difficulty: str = "medium", question_types: list = None,
                            count: int = 10, total_score: int = 100) -> dict:
        kp_str = "、".join(knowledge_points) if knowledge_points else "综合"
        qt_str = "、".join(question_types) if question_types else "选择题"
        system_prompt = f"""你是一位专业的命题专家。请根据要求生成试卷。

学科：{subject}
年级：{grade}
知识点：{kp_str}
难度：{difficulty}
题型：{qt_str}
题目数量：{count}
总分：{total_score}

题目要求：
1. 题目内容准确、严谨，符合课标要求
2. 选项设计合理，干扰项有效
3. 解析详细，说明解题思路
4. 难度分布合理（简单30%、中等50%、困难20%）

输出JSON：
{{
  "title": "试卷标题（含学科和知识点）",
  "questions": [
    {{
      "id": 1,
      "type": "choice|fill_blank|true_false|short_answer|calculation",
      "score": 5,
      "difficulty": "easy|medium|hard",
      "content": "题干（含必要的数学公式、图表描述等）",
      "options": ["A选项", "B选项", "C选项", "D选项"],
      "answer": "答案",
      "analysis": "详细解析（含解题步骤和知识点）"
    }}
  ]
}}"""
        try:
            return await self._chat_json([
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": f"请生成{subject}试卷，共{count}题，总分{total_score}分"},
            ])
        except RuntimeError:
            return self._fallback_exam(subject, grade, knowledge_points, difficulty, question_types, count, total_score)

    def _fallback_animation(self, prompt: str, anim_type: str) -> dict:
        category = self._animation_category(prompt)
        if category == "cylinder":
            return self._fallback_cylinder_animation(prompt, anim_type)
        if category == "function":
            return self._fallback_function_animation(prompt, anim_type)
        if category == "photosynthesis":
            return self._fallback_photosynthesis_animation(prompt, anim_type)
        if category == "chemistry":
            return self._fallback_chemistry_animation(prompt, anim_type)
        if category == "orbit":
            return self._fallback_orbit_animation(prompt, anim_type)
        if category == "motion":
            return self._fallback_motion_animation(prompt, anim_type)
        if category == "geometry":
            return self._fallback_geometry_animation(prompt, anim_type)
        return self._fallback_general_animation(prompt, anim_type)

    def _animation_meta(self, prompt: str, anim_type: str) -> tuple[str, str]:
        title = html_lib.escape(prompt[:24] or "教学动画")
        type_label = {
            "math": "数学",
            "physics": "物理",
            "chemistry": "化学",
            "general": "通用",
        }.get(anim_type, "通用")
        return title, type_label

    def _animation_result(self, prompt: str, anim_type: str, html: str, description: str, scenes: list[dict] | None = None) -> dict:
        title = html_lib.escape(prompt[:24] or "教学动画")
        return {
            "title": title,
            "description": description,
            "html": html,
            "scenes": scenes or [{"id": 1, "name": "演示", "duration": 8, "narration": "观察动画变化"}],
            "totalDuration": 12,
            "interactive": True,
        }

    def _fallback_general_animation(self, prompt: str, anim_type: str) -> dict:
        title, type_label = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#12372d;'>
  <style>
    @keyframes floatBall {{
      0% {{ transform: translateX(0) translateY(0); }}
      25% {{ transform: translateX(160px) translateY(-34px); }}
      50% {{ transform: translateX(320px) translateY(0); }}
      75% {{ transform: translateX(480px) translateY(-24px); }}
      100% {{ transform: translateX(620px) translateY(0); }}
    }}
    @keyframes pulseGlow {{
      0%,100% {{ box-shadow: 0 8px 20px rgba(0,168,112,.16); }}
      50% {{ box-shadow: 0 12px 32px rgba(0,168,112,.28); }}
    }}
    @keyframes drift {{
      0%,100% {{ transform: translateY(0); opacity: .28; }}
      50% {{ transform: translateY(-14px); opacity: .44; }}
    }}
    @keyframes scanLine {{
      0% {{ transform: translateX(-20%); opacity: .2; }}
      50% {{ opacity: .8; }}
      100% {{ transform: translateX(115%); opacity: .2; }}
    }}
    @keyframes stepPulse {{
      0%,100% {{ transform: scale(1); border-color:#d9e7dc; }}
      50% {{ transform: scale(1.03); border-color:#00a870; }}
    }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #d9e7dc;'>
    <div>
      <h2 style='font-size:26px;margin:0 0 6px;line-height:1.2;color:#00543d;'>{title}</h2>
      <p style='font-size:14px;color:#6b7f76;margin:0;'>{type_label}教学动画 · 清爽课堂演示版</p>
    </div>
    <span style='padding:8px 14px;border-radius:18px;background:#e8f7ef;color:#007a52;font-size:13px;font-weight:700;'>AI 动画</span>
  </div>
  <div style='position:absolute;left:54px;right:54px;top:112px;bottom:96px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;'>
    <div style='position:absolute;left:48px;right:48px;top:112px;height:3px;background:#d9e7dc;border-radius:2px;'></div>
    <div style='position:absolute;left:48px;right:48px;top:112px;height:3px;background:linear-gradient(90deg,transparent,#00a870,transparent);animation:scanLine 4s linear infinite;'></div>
    <div style='position:absolute;left:70px;top:170px;width:66px;height:66px;border-radius:50%;background:#00a870;animation:floatBall 6s ease-in-out infinite,pulseGlow 2s ease-in-out infinite;'></div>
    <div style='position:absolute;left:154px;top:150px;width:18px;height:18px;border-radius:50%;background:#f59e0b;animation:drift 3.2s ease-in-out infinite;'></div>
    <div style='position:absolute;left:334px;top:136px;width:26px;height:26px;border-radius:50%;background:#93c5fd;animation:drift 4s ease-in-out infinite;'></div>
    <div style='position:absolute;left:554px;top:158px;width:14px;height:14px;border-radius:50%;background:#86efac;animation:drift 2.8s ease-in-out infinite;'></div>
  </div>
  <div style='position:absolute;left:94px;right:94px;bottom:116px;display:grid;grid-template-columns:repeat(3,1fr);gap:12px;'>
    <div style='padding:14px;border:1px solid #d9e7dc;border-radius:12px;background:#fff;animation:stepPulse 2.4s ease-in-out infinite;'>1. 提出问题</div>
    <div style='padding:14px;border:1px solid #d9e7dc;border-radius:12px;background:#fff;animation:stepPulse 2.4s ease-in-out infinite .4s;'>2. 动态观察</div>
    <div style='padding:14px;border:1px solid #d9e7dc;border-radius:12px;background:#fff;animation:stepPulse 2.4s ease-in-out infinite .8s;'>3. 归纳结论</div>
  </div>
  <div style='position:absolute;left:36px;right:36px;bottom:30px;display:flex;gap:10px;align-items:center;color:#6b7f76;'>
    <span style='padding:9px 16px;border-radius:18px;background:#00543d;color:#fff;font-weight:700;'>演示动画</span>
    <span style='font-size:13px;'>可保存、可预览、可插入课件</span>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, f"{anim_type} 教学动画演示")


    def _fallback_geometry_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#143b31;'>
  <style>
    @keyframes drawSide {{ 0% {{ stroke-dashoffset: 760; }} 60%,100% {{ stroke-dashoffset: 0; }} }}
    @keyframes popAngle {{ 0%,55% {{ transform: scale(0); opacity: 0; }} 70%,90% {{ transform: scale(1); opacity: 1; }} 100% {{ transform: scale(0); opacity: 0; }} }}
    @keyframes growA {{ 0%,12% {{ width: 0; }} 34%,84% {{ width: 44.4%; }} 96%,100% {{ width: 0; }} }}
    @keyframes growB {{ 0%,28% {{ width: 0; }} 50%,84% {{ width: 33.3%; }} 96%,100% {{ width: 0; }} }}
    @keyframes growC {{ 0%,44% {{ width: 0; }} 66%,84% {{ width: 22.3%; }} 96%,100% {{ width: 0; }} }}
    @keyframes stamp {{ 0%,70% {{ transform: scale(0) rotate(-12deg); opacity: 0; }} 82%,92% {{ transform: scale(1) rotate(-6deg); opacity: 1; }} 100% {{ transform: scale(0); opacity: 0; }} }}
    @keyframes barPulse {{ 0%,100% {{ box-shadow:0 6px 16px rgba(0,84,61,.10); }} 50% {{ box-shadow:0 10px 24px rgba(0,84,61,.18); }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #d9e7dc;'>
    <div>
      <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
      <p style='margin:0;font-size:14px;color:#6b7f76;'>三角形三个内角拼合成一个平角 = 180°</p>
    </div>
    <span style='padding:8px 14px;border-radius:18px;background:#e8f7ef;color:#007a52;font-size:13px;font-weight:700;'>几何图形</span>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;'>
    <div style='position:absolute;left:36px;top:30px;width:45%;bottom:30px;display:flex;align-items:center;justify-content:center;'>
      <svg viewBox='0 0 320 280' style='width:100%;height:100%;'>
        <polygon points='160,34 44,242 276,242' fill='rgba(0,168,112,.06)' stroke='#00a870' stroke-width='5' stroke-linejoin='round' stroke-dasharray='760' stroke-dashoffset='760' style='animation:drawSide 6s ease-in-out infinite;'/>
        <circle cx='160' cy='34' r='10' fill='#00a870' style='transform-box:fill-box;transform-origin:center;animation:popAngle 6s ease-in-out infinite;'/>
        <text x='176' y='56' fill='#00543d' font-size='17' font-weight='700'>∠α 80°</text>
        <circle cx='44' cy='242' r='10' fill='#f59e0b' style='transform-box:fill-box;transform-origin:center;animation:popAngle 6s ease-in-out infinite .6s;'/>
        <text x='14' y='234' fill='#92400e' font-size='17' font-weight='700'>∠β 60°</text>
        <circle cx='276' cy='242' r='10' fill='#3b82f6' style='transform-box:fill-box;transform-origin:center;animation:popAngle 6s ease-in-out infinite 1.2s;'/>
        <text x='220' y='234' fill='#1d4ed8' font-size='17' font-weight='700'>∠γ 40°</text>
      </svg>
    </div>
    <div style='position:absolute;right:30px;top:34px;width:47%;bottom:34px;display:flex;flex-direction:column;justify-content:center;gap:20px;'>
      <div style='text-align:center;font-size:16px;color:#00543d;font-weight:700;'>拼角验证：三个内角 → 一条平角</div>
      <div style='position:relative;height:46px;border-radius:10px;background:#f1f5f4;border:1px solid #e1eee4;overflow:hidden;animation:barPulse 3s ease-in-out infinite;'>
        <div style='position:absolute;left:0;top:0;height:100%;background:linear-gradient(90deg,#00a870,#34d399);display:flex;align-items:center;justify-content:center;color:#fff;font-size:14px;font-weight:700;overflow:hidden;white-space:nowrap;animation:growA 6s ease-in-out infinite;'>α 80°</div>
        <div style='position:absolute;left:44.4%;top:0;height:100%;background:linear-gradient(90deg,#f59e0b,#fbbf24);display:flex;align-items:center;justify-content:center;color:#fff;font-size:14px;font-weight:700;overflow:hidden;white-space:nowrap;animation:growB 6s ease-in-out infinite;'>β 60°</div>
        <div style='position:absolute;left:77.7%;top:0;height:100%;background:linear-gradient(90deg,#3b82f6,#60a5fa);display:flex;align-items:center;justify-content:center;color:#fff;font-size:14px;font-weight:700;overflow:hidden;white-space:nowrap;animation:growC 6s ease-in-out infinite;'>γ 40°</div>
      </div>
      <div style='display:flex;justify-content:space-between;font-size:13px;color:#6b7f76;padding:0 2px;'><span>0°</span><span>180°</span></div>
      <div style='text-align:center;font-size:22px;font-weight:800;color:#00543d;'>80° + 60° + 40° = 180°</div>
      <div style='margin:0 auto;width:116px;height:116px;border-radius:50%;background:#e8f7ef;border:3px solid #00a870;display:flex;align-items:center;justify-content:center;font-size:26px;font-weight:800;color:#00543d;animation:stamp 6s ease-in-out infinite;'>180°</div>
    </div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "三角形内角和动态演示：拼角成平角 180°")


    def _fallback_function_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#15324a;'>
  <style>
    @keyframes drawCurve {{ 0% {{ stroke-dashoffset: 760; }} 100% {{ stroke-dashoffset: 0; }} }}
    @keyframes movePoint {{ 0% {{ transform:translate(70px,360px); }} 25% {{ transform:translate(205px,230px); }} 50% {{ transform:translate(340px,150px); }} 75% {{ transform:translate(475px,230px); }} 100% {{ transform:translate(610px,360px); }} }}
    @keyframes coeffPulse {{ 0%,100% {{ background:#e0f2fe; transform:scale(1); }} 50% {{ background:#bbf7d0; transform:scale(1.04); }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #d9e7dc;'>
    <div>
      <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
      <p style='margin:0;font-size:14px;color:#6b7f76;'>观察二次函数图像随参数变化的趋势</p>
    </div>
    <span style='padding:8px 14px;border-radius:18px;background:#e8f7ef;color:#007a52;font-size:13px;font-weight:700;'>函数图像</span>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;'>
    <svg viewBox='0 0 680 420' style='position:absolute;left:24px;top:18px;width:calc(100% - 270px);height:calc(100% - 36px);background:#fbfefd;border:1px solid #e1eee4;border-radius:14px;'>
      <defs><pattern id='grid' width='32' height='32' patternUnits='userSpaceOnUse'><path d='M32 0H0V32' fill='none' stroke='#e5efe8' stroke-width='1'/></pattern></defs>
      <rect x='0' y='0' width='680' height='420' fill='url(#grid)'/>
      <line x1='45' y1='350' x2='640' y2='350' stroke='#8aa39a' stroke-width='2'/>
      <line x1='340' y1='35' x2='340' y2='382' stroke='#8aa39a' stroke-width='2'/>
      <path d='M70 360 C150 265 230 175 340 150 C450 175 530 265 610 360' fill='none' stroke='#00a870' stroke-width='6' stroke-linecap='round' stroke-dasharray='760' stroke-dashoffset='760' style='animation:drawCurve 4s ease-in-out infinite alternate;'/>
      <circle r='9' fill='#f97316' style='animation:movePoint 4s ease-in-out infinite;'/>
      <text x='356' y='70' fill='#00543d' font-size='20' font-weight='700'>y = ax² + bx + c</text>
      <text x='522' y='332' fill='#64748b' font-size='14'>x</text>
      <text x='355' y='54' fill='#64748b' font-size='14'>y</text>
    </svg>
    <div style='position:absolute;right:24px;top:28px;width:210px;display:grid;gap:12px;'>
      <div style='padding:14px;border-radius:12px;background:#ecfdf5;border:1px solid #bbf7d0;animation:coeffPulse 2.5s ease-in-out infinite;'><strong style='color:#00543d;'>a</strong><br/><span style='font-size:13px;color:#6b7f76;'>控制开口方向和宽窄</span></div>
      <div style='padding:14px;border-radius:12px;background:#fffbeb;border:1px solid #fde68a;animation:coeffPulse 2.5s ease-in-out infinite .4s;'><strong style='color:#92400e;'>b</strong><br/><span style='font-size:13px;color:#6b7f76;'>影响对称轴位置</span></div>
      <div style='padding:14px;border-radius:12px;background:#eff6ff;border:1px solid #bfdbfe;animation:coeffPulse 2.5s ease-in-out infinite .8s;'><strong style='color:#1d4ed8;'>c</strong><br/><span style='font-size:13px;color:#6b7f76;'>决定与 y 轴交点</span></div>
    </div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "函数图像动态演示")

    def _fallback_cylinder_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#143b31;'>
  <style>
    @keyframes sliceMove {{ 0%,100% {{ transform:translateX(0); opacity:.9; }} 50% {{ transform:translateX(130px); opacity:.65; }} }}
    @keyframes fillRise {{ 0% {{ height:0; }} 100% {{ height:156px; }} }}
    @keyframes formulaGlow {{ 0%,100% {{ border-color:#d9e7dc; }} 50% {{ border-color:#00a870; }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;border-bottom:1px solid #d9e7dc;'>
    <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
    <p style='margin:0;color:#6b7f76;font-size:14px;'>把圆柱看作“底面积 × 高”的累积</p>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);'>
    <div style='position:absolute;left:70px;top:70px;width:180px;height:220px;'>
      <div style='position:absolute;left:30px;top:30px;width:120px;height:156px;background:linear-gradient(90deg,#86efac,#d1fae5,#86efac);border-left:2px solid #00a870;border-right:2px solid #00a870;'></div>
      <div style='position:absolute;left:30px;top:10px;width:120px;height:42px;border-radius:50%;background:#d1fae5;border:2px solid #00a870;'></div>
      <div style='position:absolute;left:30px;top:164px;width:120px;height:42px;border-radius:50%;background:#a7f3d0;border:2px solid #00a870;'></div>
      <div style='position:absolute;left:30px;bottom:14px;width:120px;background:rgba(0,168,112,.22);animation:fillRise 3s ease-in-out infinite alternate;'></div>
    </div>
    <div style='position:absolute;left:320px;top:92px;display:grid;gap:7px;'>
      <div style='width:150px;height:14px;border-radius:50%;background:#d1fae5;border:1px solid #00a870;animation:sliceMove 2.8s ease-in-out infinite;'></div>
      <div style='width:150px;height:14px;border-radius:50%;background:#bbf7d0;border:1px solid #00a870;animation:sliceMove 2.8s ease-in-out infinite .15s;'></div>
      <div style='width:150px;height:14px;border-radius:50%;background:#86efac;border:1px solid #00a870;animation:sliceMove 2.8s ease-in-out infinite .3s;'></div>
      <div style='width:150px;height:14px;border-radius:50%;background:#4ade80;border:1px solid #00a870;animation:sliceMove 2.8s ease-in-out infinite .45s;'></div>
    </div>
    <div style='position:absolute;right:38px;top:86px;width:230px;padding:24px;border-radius:14px;background:#f8faf8;border:1px solid #d9e7dc;animation:formulaGlow 2.6s ease-in-out infinite;'>
      <div style='font-size:16px;color:#00543d;margin-bottom:12px;font-weight:700;'>体积公式</div>
      <div style='font-size:32px;font-weight:800;color:#12372d;'>V = πr²h</div>
      <p style='font-size:14px;line-height:1.7;color:#6b7f76;'>底面积 πr² 沿高度 h 连续叠加，得到圆柱体积。</p>
    </div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "圆柱体积推导动画")

    def _fallback_photosynthesis_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#14532d;'>
  <style>
    @keyframes ray {{ 0% {{ opacity:.15; transform:translateY(-12px); }} 50% {{ opacity:.85; transform:translateY(8px); }} 100% {{ opacity:.15; transform:translateY(-12px); }} }}
    @keyframes bubbleIn {{ 0% {{ transform:translateX(0); opacity:.2; }} 50% {{ opacity:1; }} 100% {{ transform:translateX(235px); opacity:.2; }} }}
    @keyframes oxygenOut {{ 0% {{ transform:translate(0,0); opacity:.1; }} 100% {{ transform:translate(180px,-90px); opacity:1; }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;border-bottom:1px solid #d9e7dc;'>
    <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
    <p style='margin:0;color:#6b7f76;font-size:14px;'>光能驱动二氧化碳和水转化为有机物</p>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;'>
    <div style='position:absolute;left:42px;top:36px;width:90px;height:90px;border-radius:50%;background:#facc15;box-shadow:0 10px 28px rgba(250,204,21,.35);'></div>
    <div style='position:absolute;left:160px;top:72px;width:5px;height:170px;background:#fde047;transform:rotate(25deg);animation:ray 2.2s ease-in-out infinite;'></div>
    <div style='position:absolute;left:204px;top:72px;width:5px;height:190px;background:#fde047;transform:rotate(18deg);animation:ray 2.2s ease-in-out infinite .25s;'></div>
    <div style='position:absolute;left:270px;top:92px;width:280px;height:164px;border-radius:50% 8% 50% 8%;background:linear-gradient(135deg,#16a34a,#bbf7d0);transform:rotate(-8deg);box-shadow:inset 0 0 30px rgba(255,255,255,.45),0 14px 28px rgba(0,84,61,.12);'></div>
    <div style='position:absolute;left:394px;top:164px;width:150px;height:6px;background:#166534;transform:rotate(-8deg);border-radius:4px;'></div>
    <div style='position:absolute;left:52px;bottom:54px;padding:14px 18px;border-radius:14px;background:#eff6ff;border:1px solid #bfdbfe;font-weight:700;'>CO₂ + H₂O</div>
    <div style='position:absolute;left:116px;bottom:125px;width:26px;height:26px;border-radius:50%;background:#38bdf8;animation:bubbleIn 3s ease-in-out infinite;'></div>
    <div style='position:absolute;left:156px;bottom:160px;width:20px;height:20px;border-radius:50%;background:#22c55e;animation:bubbleIn 3s ease-in-out infinite .6s;'></div>
    <div style='position:absolute;right:168px;top:120px;width:28px;height:28px;border-radius:50%;background:#e0f2fe;border:2px solid #38bdf8;animation:oxygenOut 2.8s ease-in-out infinite;'></div>
    <div style='position:absolute;right:34px;bottom:54px;padding:16px 22px;border-radius:14px;background:#ecfdf5;border:1px solid #bbf7d0;box-shadow:0 8px 18px rgba(15,84,61,.08);'>
      <strong style='color:#00543d;'>产物</strong><br/>葡萄糖 + O₂
    </div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "光合作用过程动画")

    def _fallback_chemistry_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#143b31;'>
  <style>
    @keyframes collideA {{ 0%,100% {{ transform:translate(0,0); }} 50% {{ transform:translate(220px,40px); }} }}
    @keyframes collideB {{ 0%,100% {{ transform:translate(0,0); }} 50% {{ transform:translate(-220px,-40px); }} }}
    @keyframes flash {{ 0%,45%,100% {{ opacity:.15; transform:scale(.7); }} 50% {{ opacity:1; transform:scale(1.5); }} }}
    @keyframes product {{ 0%,55% {{ opacity:0; transform:scale(.5); }} 80%,100% {{ opacity:1; transform:scale(1); }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;border-bottom:1px solid #d9e7dc;'>
    <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
    <p style='margin:0;color:#6b7f76;font-size:14px;'>观察微粒碰撞、重组并形成生成物</p>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);'>
    <div style='position:absolute;left:80px;top:122px;width:74px;height:74px;border-radius:50%;background:#93c5fd;animation:collideA 3s ease-in-out infinite;border:3px solid #2563eb;'></div>
    <div style='position:absolute;right:100px;top:162px;width:68px;height:68px;border-radius:50%;background:#fdba74;animation:collideB 3s ease-in-out infinite;border:3px solid #f97316;'></div>
    <div style='position:absolute;left:50%;top:150px;width:96px;height:96px;margin-left:-48px;border-radius:50%;background:#fef3c7;animation:flash 3s ease-in-out infinite;border:2px solid #f59e0b;'></div>
    <div style='position:absolute;left:50%;top:138px;margin-left:-82px;display:flex;gap:12px;animation:product 3s ease-in-out infinite;'>
      <div style='width:62px;height:62px;border-radius:50%;background:#86efac;border:3px solid #00a870;'></div>
      <div style='width:62px;height:62px;border-radius:50%;background:#c4b5fd;border:3px solid #7c3aed;'></div>
    </div>
    <div style='position:absolute;left:60px;bottom:44px;font-size:20px;color:#00543d;font-weight:700;'>反应物</div>
    <div style='position:absolute;left:50%;bottom:42px;transform:translateX(-50%);font-size:32px;color:#00a870;'>→</div>
    <div style='position:absolute;right:70px;bottom:44px;font-size:20px;color:#00543d;font-weight:700;'>生成物</div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "化学反应碰撞动画")

    def _fallback_orbit_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#143b31;'>
  <style>
    @keyframes spin {{ from {{ transform:rotate(0deg); }} to {{ transform:rotate(360deg); }} }}
    @keyframes rayPulse {{ 0%,100% {{ opacity:.28; }} 50% {{ opacity:.82; }} }}
    @keyframes focusGlow {{ 0%,100% {{ transform:scale(1); box-shadow:0 6px 14px rgba(0,84,61,.08); }} 50% {{ transform:scale(1.02); box-shadow:0 10px 22px rgba(0,84,61,.16); }} }}
    .season-radio {{ position:absolute; opacity:0; pointer-events:none; }}
    .season-btn {{ height:46px; border-radius:13px; border:1px solid #d9e7dc; background:#fff; color:#516b61; display:flex; align-items:center; justify-content:center; gap:6px; font-weight:700; cursor:pointer; transition:all .22s ease; box-shadow:0 4px 12px rgba(15,84,61,.05); user-select:none; }}
    .season-btn:hover {{ transform:translateY(-1px); border-color:#00a870; color:#00543d; }}
    .season-btn:active {{ transform:translateY(0); }}
    .earth-dot {{ position:absolute; width:70px; height:70px; border-radius:50%; background:linear-gradient(135deg,#60a5fa 0%,#60a5fa 48%,#22c55e 49%,#86efac 100%); border:4px solid #fff; box-shadow:0 10px 24px rgba(0,84,61,.18); transition:all .35s ease; }}
    .axis {{ position:absolute; left:50%; top:-8px; width:3px; height:86px; background:#00543d; transform:translateX(-50%) rotate(-23deg); border-radius:2px; opacity:.78; }}
    .earth-dot::after {{ content:''; position:absolute; inset:0; border-radius:50%; background:linear-gradient(90deg,rgba(255,255,255,.38),transparent 55%,rgba(0,0,0,.14)); animation:spin 5s linear infinite; }}
    .season-card {{ position:absolute; right:28px; top:34px; width:240px; min-height:132px; padding:18px; border:1px solid #d9e7dc; border-radius:16px; background:#f8faf8; box-shadow:0 8px 20px rgba(15,84,61,.08); opacity:0; transform:translateY(8px); transition:all .25s ease; pointer-events:none; }}
    .season-card strong {{ display:block; color:#00543d; font-size:22px; margin-bottom:8px; }}
    .season-card span {{ color:#6b7f76; font-size:14px; line-height:1.7; }}
    #season-spring:checked ~ .stage .earth-dot {{ left:116px; top:126px; }}
    #season-summer:checked ~ .stage .earth-dot {{ left:306px; top:44px; }}
    #season-autumn:checked ~ .stage .earth-dot {{ left:496px; top:126px; }}
    #season-winter:checked ~ .stage .earth-dot {{ left:306px; top:208px; }}
    #season-spring:checked ~ .stage .spring-card,
    #season-summer:checked ~ .stage .summer-card,
    #season-autumn:checked ~ .stage .autumn-card,
    #season-winter:checked ~ .stage .winter-card {{ opacity:1; transform:translateY(0); }}
    #season-spring:checked ~ .stage .spring-card strong,
    #season-summer:checked ~ .stage .summer-card strong,
    #season-autumn:checked ~ .stage .autumn-card strong,
    #season-winter:checked ~ .stage .winter-card strong {{ animation:focusGlow 2.2s ease-in-out infinite; }}
    #season-spring:checked ~ .tabs label[for='season-spring'],
    #season-summer:checked ~ .tabs label[for='season-summer'],
    #season-autumn:checked ~ .tabs label[for='season-autumn'],
    #season-winter:checked ~ .tabs label[for='season-winter'] {{ background:#00543d; color:#fff; border-color:#00543d; box-shadow:0 8px 18px rgba(0,84,61,.18); }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;border-bottom:1px solid #d9e7dc;'>
    <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
    <p style='margin:0;color:#6b7f76;font-size:14px;'>点击春夏秋冬，观察地球公转位置与太阳直射变化</p>
  </div>
  <input class='season-radio' id='season-spring' name='season' type='radio' checked>
  <input class='season-radio' id='season-summer' name='season' type='radio'>
  <input class='season-radio' id='season-autumn' name='season' type='radio'>
  <input class='season-radio' id='season-winter' name='season' type='radio'>
  <div class='stage' style='position:absolute;left:48px;right:48px;top:110px;bottom:126px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;z-index:1;'>
    <div style='position:absolute;left:54px;top:24px;padding:8px 12px;border-radius:18px;background:#e8f7ef;color:#00543d;font-size:13px;font-weight:700;'>太阳直射点随公转变化</div>
    <div style='position:absolute;left:300px;top:126px;width:92px;height:92px;border-radius:50%;background:#facc15;box-shadow:0 8px 26px rgba(250,204,21,.35);'></div>
    <div style='position:absolute;left:116px;top:72px;width:450px;height:250px;border:1.5px dashed #9ca3af;border-radius:50%;'></div>
    <div style='position:absolute;left:356px;top:166px;width:240px;height:4px;background:linear-gradient(90deg,#fde68a,transparent);transform:rotate(-18deg);transform-origin:left center;animation:rayPulse 2.4s ease-in-out infinite;'></div>
    <div style='position:absolute;left:356px;top:166px;width:240px;height:4px;background:linear-gradient(90deg,#fde68a,transparent);transform:rotate(18deg);transform-origin:left center;animation:rayPulse 2.4s ease-in-out infinite .4s;'></div>
    <div class='earth-dot'><div class='axis'></div></div>
    <div class='season-card spring-card'><strong>春分</strong><span>太阳直射赤道附近，南北半球昼夜接近等长，气温逐渐回升。</span></div>
    <div class='season-card summer-card'><strong>夏至</strong><span>北半球获得更多太阳辐射，白昼较长，正午太阳高度较高。</span></div>
    <div class='season-card autumn-card'><strong>秋分</strong><span>太阳再次直射赤道附近，昼夜接近等长，气温逐渐降低。</span></div>
    <div class='season-card winter-card'><strong>冬至</strong><span>北半球太阳高度较低，白昼较短，获得太阳辐射较少。</span></div>
    <div style='position:absolute;left:58px;bottom:26px;color:#6b7f76;font-size:13px;'>提示：地轴方向基本保持不变，这是四季变化的重要原因。</div>
  </div>
  <div class='tabs' style='position:absolute;left:74px;right:74px;bottom:56px;display:grid;grid-template-columns:repeat(4,1fr);gap:12px;z-index:2;'>
    <label class='season-btn' for='season-spring'>春分</label>
    <label class='season-btn' for='season-summer'>夏至</label>
    <label class='season-btn' for='season-autumn'>秋分</label>
    <label class='season-btn' for='season-winter'>冬至</label>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "地球公转与四季动画")

    def _fallback_motion_animation(self, prompt: str, anim_type: str) -> dict:
        title, _ = self._animation_meta(prompt, anim_type)
        html = f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,sans-serif;color:#0f172a;'>
  <style>
    @keyframes roll {{ 0% {{ transform:translateX(0) rotate(0deg); }} 100% {{ transform:translateX(520px) rotate(720deg); }} }}
    @keyframes vector {{ 0%,100% {{ width:70px; }} 50% {{ width:150px; }} }}
    @keyframes meter {{ 0% {{ width:12%; }} 100% {{ width:86%; }} }}
  </style>
  <div style='position:absolute;left:36px;right:36px;top:24px;height:64px;border-bottom:1px solid #d9e7dc;'>
    <h2 style='margin:0 0 6px;font-size:26px;color:#00543d;'>{title}</h2>
    <p style='margin:0;color:#6b7f76;font-size:14px;'>观察物体运动方向与速度大小变化</p>
  </div>
  <div style='position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);'>
    <div style='position:absolute;left:48px;top:220px;width:640px;height:8px;background:#8aa39a;transform:rotate(-10deg);transform-origin:left center;border-radius:6px;'></div>
    <div style='position:absolute;left:72px;top:148px;width:56px;height:56px;border-radius:50%;background:#f97316;animation:roll 4s ease-in-out infinite alternate;box-shadow:inset -8px -8px 0 rgba(0,0,0,.16),0 10px 20px rgba(249,115,22,.2);'></div>
    <div style='position:absolute;left:146px;top:110px;height:5px;background:#00a870;animation:vector 2.4s ease-in-out infinite;border-radius:4px;'></div>
    <div style='position:absolute;left:288px;top:94px;color:#00543d;font-weight:700;'>速度方向</div>
    <div style='position:absolute;left:56px;right:56px;bottom:72px;height:12px;background:#e2e8f0;border-radius:6px;overflow:hidden;'>
      <div style='height:100%;background:linear-gradient(90deg,#86efac,#00a870);animation:meter 4s ease-in-out infinite alternate;'></div>
    </div>
    <div style='position:absolute;left:56px;bottom:34px;color:#6b7f76;'>速度随时间变化：慢 → 快</div>
  </div>
</div>"""
        return self._animation_result(prompt, anim_type, html, "物体运动与速度变化动画")


    def _fallback_exercise(self, prompt, exercise_type, subject, knowledge_points, count):
        total = max(1, min(count or 5, 10))
        raw_topic = (prompt or "").strip()[:30] or "课堂练习"
        # 去掉结尾的练习/题型字样，避免标题拼成「…练习练习」
        topic = re.sub(
            r"(?:的)?(?:互动)?(?:练习题|题目集|练习|题目|试题|习题|题库|选择题|填空题|判断题|应用题|解答题|计算题|题)+$",
            "", raw_topic,
        ).strip() or raw_topic
        subj = (subject or "").strip()
        bank = self._question_bank(topic, subj)
        if not bank:
            bank = self._generic_question_bank(topic, subj)
        questions = []
        for idx in range(total):
            q = dict(bank[idx % len(bank)])
            q["id"] = idx + 1
            q["difficulty"] = ["easy", "medium", "hard"][idx % 3]
            q["html"] = self._exercise_html(q)
            questions.append(q)
        return {"title": (topic + "练习")[:40], "questions": questions}

    def _question_bank(self, topic, subject):
        t = (topic or "").lower()
        s = (subject or "").lower()
        combined = t + " " + s
        topic_bank = self._topic_question_bank(t, subject or "")
        if topic_bank:
            return topic_bank
        is_math = any(k in combined for k in ("数学", "math", "分数", "加减", "乘除", "方程", "几何", "面积", "比例"))
        is_chinese = any(k in combined for k in ("语文", "古诗", "词语", "阅读", "修辞", "拼音", "汉字"))
        is_english = any(k in combined for k in ("english", "英语", "grammar", "vocabulary", "tense"))
        is_science = any(k in combined for k in ("科学", "物理", "化学", "生物", "地理", "光合作用", "重力", "电路"))
        if is_math:
            return self._math_questions(topic)
        if is_chinese:
            return self._chinese_questions(topic)
        if is_english:
            return self._english_questions(topic)
        if is_science:
            return self._science_questions(topic)
        return []

    def _generic_question_bank(self, topic, subject):
        return [
            {
                "type": "choice",
                "question": f"关于「{topic}」，下列说法正确的是？",
                "options": [f"「{topic}」是本课的重要学习内容", f"「{topic}」与本课无关", f"「{topic}」只需死记硬背", f"「{topic}」无需理解"],
                "answer": f"「{topic}」是本课的重要学习内容",
                "explanation": f"「{topic}」是核心知识点，需要重点掌握并灵活运用。",
            },
            {
                "type": "choice",
                "question": f"学习「{topic}」时，最有效的方法是？",
                "options": ["理解原理并结合实例练习", "只看不练", "抄袭同学的答案", "等考试前突击"],
                "answer": "理解原理并结合实例练习",
                "explanation": "理解性学习加反复练习是掌握知识的最佳途径。",
            },
            {
                "type": "choice",
                "question": f"下列哪项不属于「{topic}」的应用场景？",
                "options": [f"课堂讲解中举例说明", f"生活实践中观察现象", "与本课完全无关的其他话题", f"课后作业中运用"],
                "answer": "与本课完全无关的其他话题",
                "explanation": "知识的应用应当围绕课堂、生活和作业场景，而非无关话题。",
            },
            {
                "type": "fill_blank",
                "question": f"请简述「{topic}」的核心含义（填空）：{topic}是指______。",
                "options": [],
                "answer": f"本课程中关于{topic}的核心概念和方法",
                "explanation": f"理解{topic}的定义是进一步学习的基础。",
            },
            {
                "type": "true_false",
                "question": f"判断：「{topic}」只需要死记硬背就能掌握。",
                "options": ["正确", "错误"],
                "answer": "错误",
                "explanation": "任何知识都需要在理解的基础上灵活运用，死记硬背无法真正掌握。",
            },
        ]

    def _topic_question_bank(self, topic, subject):
        """主题感知题库：为高频学科主题提供有实质知识的题目。

        采用"最长关键词命中"策略：当多个题组都可能命中时（例如"二次函数"
        同时命中"函数"和"二次函数"两组关键词），优先返回关键词最长、最精确
        的题组，避免宽泛关键词（如"函数"）错误抢占细分知识点（如"二次函数"）。
        """
        t = (topic or "")
        combined = t + " " + (subject or "")
        best = None
        best_len = 0
        for keys, qs in self._exercise_kb():
            for k in keys:
                if k and k in combined and len(k) > best_len:
                    best = qs
                    best_len = len(k)
        return best or []

    def _exercise_kb(self):
        """主题感知题库：覆盖历史/地理/生物/化学/物理/数学/语文/英语高频知识点。"""
        return [
            # ========== 历史 ==========
            (["朝代", "历代", "王朝", "唐朝", "唐代", "汉朝", "汉代", "宋朝", "宋代", "明朝", "明代", "清朝", "清代", "秦朝"], [
                {"type": "choice", "question": "我国历史上第一个统一的中央集权封建王朝是？", "options": ["夏朝", "商朝", "秦朝", "汉朝"], "answer": "秦朝", "explanation": "公元前221年，秦始皇嬴政建立秦朝，是中国历史上第一个统一的中央集权封建王朝。"},
                {"type": "choice", "question": "贞观之治的皇帝是？", "options": ["唐高祖李渊", "唐太宗李世民", "唐高宗李治", "唐玄宗李隆基"], "answer": "唐太宗李世民", "explanation": "唐太宗李世民在位期间（627-649年）开创了贞观之治，是唐朝鼎盛的开端。"},
                {"type": "true_false", "question": "判断：四大发明中的活字印刷术是北宋毕昇发明的。", "options": ["正确", "错误"], "answer": "正确", "explanation": "北宋庆历年间（约1045年），毕昇发明了胶泥活字印刷术，比欧洲早约400年。"},
                {"type": "fill_blank", "question": "丝绸之路的起点是长安（今____），终点到达中亚、西亚乃至欧洲。", "options": [], "answer": "西安", "explanation": "汉代张骞出使西域开辟的丝绸之路，起点是西汉都城长安（今陕西西安）。"},
            ]),
            (["丝绸之路"], [
                {"type": "choice", "question": "开通陆上丝绸之路的历史人物是？", "options": ["张骞", "玄奘", "郑和", "班超"], "answer": "张骞", "explanation": "汉武帝派张骞两次出使西域，开通了连接东西方的丝绸之路。"},
                {"type": "choice", "question": "下列哪项不是丝绸之路运输的商品？", "options": ["丝绸", "瓷器", "茶叶", "电视机"], "answer": "电视机", "explanation": "古代丝绸之路主要运输丝绸、瓷器、茶叶、香料等，电视机是现代工业产品。"},
                {"type": "true_false", "question": "判断：郑和下西洋属于海上丝绸之路的活动。", "options": ["正确", "错误"], "answer": "正确", "explanation": "明朝郑和七次下西洋，是海上丝绸之路的壮举，比哥伦布航海早约半个世纪。"},
            ]),
            (["工业革命"], [
                {"type": "choice", "question": "第一次工业革命的标志是？", "options": ["蒸汽机的改良与广泛使用", "电力的广泛应用", "计算机的发明", "内燃机的发明"], "answer": "蒸汽机的改良与广泛使用", "explanation": "18世纪60年代，瓦特改良蒸汽机，标志着第一次工业革命（蒸汽时代）的到来。"},
                {"type": "choice", "question": "第二次工业革命的核心动力是？", "options": ["蒸汽", "电力", "核能", "太阳能"], "answer": "电力", "explanation": "19世纪70年代开始的第二次工业革命以电力的广泛应用为标志，人类进入电气时代。"},
                {"type": "true_false", "question": "判断：珍妮纺纱机的发明拉开了第一次工业革命的序幕。", "options": ["正确", "错误"], "answer": "正确", "explanation": "1765年哈格里夫斯发明珍妮纺纱机，是第一次工业革命开始的标志之一。"},
            ]),
            (["抗日战争", "抗战"], [
                {"type": "choice", "question": "抗日战争全面爆发的标志是？", "options": ["九一八事变", "七七事变（卢沟桥事变）", "西安事变", "八一三事变"], "answer": "七七事变（卢沟桥事变）", "explanation": "1937年7月7日的卢沟桥事变标志着中国全民族抗战的开始。"},
                {"type": "choice", "question": "抗日战争中敌后战场的总指挥是？", "options": ["蒋介石", "毛泽东", "朱德", "彭德怀"], "answer": "毛泽东", "explanation": "中国共产党领导八路军、新四军开辟敌后战场，毛泽东是战略总指挥。"},
                {"type": "fill_blank", "question": "抗日战争从1931年九一八事变开始，到____年日本投降结束，历时14年。", "options": [], "answer": "1945", "explanation": "1945年8月15日日本宣布无条件投降，9月2日正式签署投降书。"},
            ]),
            (["文艺复兴"], [
                {"type": "choice", "question": "文艺复兴运动最早发源于？", "options": ["法国", "英国", "意大利", "德国"], "answer": "意大利", "explanation": "14世纪文艺复兴首先在意大利的佛罗伦萨等城市兴起，随后扩展到欧洲各地。"},
                {"type": "choice", "question": "文艺复兴的核心思想是？", "options": ["神权至上", "人文主义", "君权神授", "禁欲主义"], "answer": "人文主义", "explanation": "人文主义主张以人为中心，肯定人的价值与尊严，反对中世纪的神学束缚。"},
                {"type": "true_false", "question": "判断：莎士比亚是文艺复兴时期英国杰出的戏剧家。", "options": ["正确", "错误"], "answer": "正确", "explanation": "莎士比亚（1564-1616）是英国文艺复兴时期最伟大的剧作家，代表作有《哈姆雷特》等。"},
            ]),
            (["辛亥革命"], [
                {"type": "choice", "question": "辛亥革命爆发于哪一年？", "options": ["1898年", "1911年", "1919年", "1921年"], "answer": "1911年", "explanation": "1911年（农历辛亥年）武昌起义爆发，标志着辛亥革命的开始。"},
                {"type": "choice", "question": "辛亥革命的历史意义不包括？", "options": ["推翻了两千多年的封建君主专制", "建立了中华民国", "使中国完全摆脱半殖民地", "传播了民主共和观念"], "answer": "使中国完全摆脱半殖民地", "explanation": "辛亥革命推翻了清朝统治和封建帝制，但没有改变中国半殖民地半封建的社会性质。"},
                {"type": "fill_blank", "question": "辛亥革命的领导者是____（人名），被尊称为国父。", "options": [], "answer": "孙中山", "explanation": "孙中山领导同盟会发动辛亥革命，建立中华民国，被尊称为中华民国国父。"},
            ]),
            # ========== 地理 ==========
            (["气候", "气候类型", "气温降水"], [
                {"type": "choice", "question": "影响气候的基本因素不包括？", "options": ["纬度位置", "海陆位置", "地形", "学生人数"], "answer": "学生人数", "explanation": "气候主要受纬度、海陆、地形、洋流等自然因素影响，与学生人数无关。"},
                {"type": "choice", "question": "我国气候的主要特征是？", "options": ["单一热带气候", "季风气候显著", "全是温带海洋性", "全是极地气候"], "answer": "季风气候显著", "explanation": "我国气候复杂多样，季风气候显著是最大特征，雨热同期有利于农业。"},
                {"type": "true_false", "question": "判断：赤道附近地区终年高温多雨。", "options": ["正确", "错误"], "answer": "正确", "explanation": "赤道地区受赤道低气压带控制，全年高温多雨，属于热带雨林气候。"},
            ]),
            (["地形", "地貌", "地势"], [
                {"type": "choice", "question": "我国地形的主要特征是？", "options": ["以平原为主", "山地高原面积广大", "全是盆地", "以丘陵为主"], "answer": "山地高原面积广大", "explanation": "我国地形复杂多样，山区（含山地、高原、丘陵）面积约占全国陆地面积的三分之二。"},
                {"type": "choice", "question": "下列不属于五种基本地形的是？", "options": ["平原", "高原", "盆地", "冰川"], "answer": "冰川", "explanation": "五种基本地形是山地、平原、高原、盆地、丘陵，冰川不属于基本地形类型。"},
                {"type": "fill_blank", "question": "我国地势第一级阶梯与第二级阶梯的分界线是____山脉。", "options": [], "answer": "昆仑—祁连—横断", "explanation": "昆仑山—祁连山—横断山脉是一、二级阶梯分界线；大兴安岭—太行山—巫山—雪峰山是二、三级阶梯分界线。"},
            ]),
            (["河流", "水系", "长江", "黄河"], [
                {"type": "choice", "question": "我国最长的河流是？", "options": ["黄河", "长江", "珠江", "黑龙江"], "answer": "长江", "explanation": "长江全长约6300公里，是中国第一长河，世界第三长河。"},
                {"type": "choice", "question": "黄河下游河床高于地面的河段称为？", "options": ["地上河", "峡谷", "三角洲", "冲积扇"], "answer": "地上河", "explanation": "黄河中游流经黄土高原携带大量泥沙，下游泥沙沉积使河床抬高形成地上河。"},
                {"type": "true_false", "question": "判断：长江发源于青藏高原的唐古拉山脉。", "options": ["正确", "错误"], "answer": "正确", "explanation": "长江发源于青藏高原唐古拉山脉主峰各拉丹冬，最终注入东海。"},
            ]),
            (["地球", "地球运动", "自转公转"], [
                {"type": "choice", "question": "地球自转的方向是？", "options": ["自东向西", "自西向东", "自南向北", "自北向南"], "answer": "自西向东", "explanation": "地球自西向东自转，周期约24小时，产生昼夜交替和时间差异。"},
                {"type": "choice", "question": "地球上产生四季更替的原因是？", "options": ["地球自转", "地球公转且地轴倾斜", "月球引力", "太阳活动"], "answer": "地球公转且地轴倾斜", "explanation": "地球绕太阳公转，且地轴与公转轨道面成66.5°夹角，导致太阳直射点移动，形成四季。"},
                {"type": "fill_blank", "question": "地球公转一周的时间约为____天。", "options": [], "answer": "365", "explanation": "地球公转一周约365.25天，即一年，故每四年设一个闰年。"},
            ]),
            # ========== 生物 ==========
            (["细胞"], [
                {"type": "choice", "question": "植物细胞特有的结构是？", "options": ["细胞膜", "细胞质", "细胞壁", "细胞核"], "answer": "细胞壁", "explanation": "细胞壁、叶绿体和大的液泡是植物细胞特有的结构。"},
                {"type": "choice", "question": "细胞工厂的动力车间是？", "options": ["线粒体", "叶绿体", "核糖体", "内质网"], "answer": "线粒体", "explanation": "线粒体是细胞的动力车间，为细胞生命活动提供约95%的能量。"},
                {"type": "true_false", "question": "判断：动物细胞没有细胞壁。", "options": ["正确", "错误"], "answer": "正确", "explanation": "动物细胞最外层是细胞膜，没有细胞壁、叶绿体和大的中央液泡。"},
            ]),
            (["光合作用"], [
                {"type": "choice", "question": "光合作用进行的场所是？", "options": ["线粒体", "叶绿体", "细胞核", "液泡"], "answer": "叶绿体", "explanation": "光合作用在叶绿体中进行，叶绿体含有叶绿素能吸收光能。"},
                {"type": "choice", "question": "光合作用的原料不包括？", "options": ["二氧化碳", "水", "光能", "氧气"], "answer": "氧气", "explanation": "氧气是光合作用的产物而非原料。原料是二氧化碳和水，条件是光照。"},
                {"type": "fill_blank", "question": "光合作用产生有机物，同时释放____。", "options": [], "answer": "氧气", "explanation": "光合作用产生有机物和氧气，维持了生物圈的碳氧平衡。"},
            ]),
            (["生态系统"], [
                {"type": "choice", "question": "生态系统中数量最多的是？", "options": ["生产者", "消费者", "分解者", "非生物部分"], "answer": "生产者", "explanation": "生产者（绿色植物）通过光合作用将无机物转化为有机物，是生态系统的基石。"},
                {"type": "choice", "question": "下列食物链正确的是？", "options": ["草→兔→鹰", "阳光→草→兔", "鹰→兔→草", "兔→草"], "answer": "草→兔→鹰", "explanation": "食物链从生产者开始，箭头指向捕食者，不包括非生物部分和分解者。"},
                {"type": "true_false", "question": "判断：生态系统中物质是循环的，能量是单向流动的。", "options": ["正确", "错误"], "answer": "正确", "explanation": "物质在生物与无机环境间循环，能量沿食物链单向流动、逐级递减。"},
            ]),
            (["遗传", "基因", "DNA"], [
                {"type": "choice", "question": "生物体遗传的基本单位是？", "options": ["细胞", "基因", "染色体", "蛋白质"], "answer": "基因", "explanation": "基因是控制生物性状的遗传单位，是有遗传效应的DNA片段。"},
                {"type": "choice", "question": "DNA分子的空间结构是？", "options": ["单螺旋", "双螺旋", "直线形", "环形"], "answer": "双螺旋", "explanation": "1953年沃森和克里克提出DNA分子的双螺旋结构模型。"},
                {"type": "true_false", "question": "判断：子代的性状完全由父方或母方一方决定。", "options": ["正确", "错误"], "answer": "错误", "explanation": "子代遗传物质来自父母双方各一半，性状由父母双方的基因共同决定。"},
            ]),
            (["人体", "消化", "呼吸", "循环"], [
                {"type": "choice", "question": "人体消化和吸收的主要器官是？", "options": ["胃", "小肠", "大肠", "口腔"], "answer": "小肠", "explanation": "小肠内有多种消化液，内壁有绒毛和微绒毛增大吸收面积，是消化吸收的主要场所。"},
                {"type": "choice", "question": "人体与外界进行气体交换的器官是？", "options": ["心脏", "肺", "肝脏", "肾脏"], "answer": "肺", "explanation": "肺是呼吸系统的主要器官，肺泡是气体交换的场所。"},
                {"type": "fill_blank", "question": "血液循环中，体循环的起点是____心室。", "options": [], "answer": "左", "explanation": "体循环从左心室出发，经主动脉到达全身各处，再经上下腔静脉回到右心房。"},
            ]),
            # ========== 化学 ==========
            (["元素周期表", "元素"], [
                {"type": "choice", "question": "元素周期表中，原子序数等于该原子的？", "options": ["中子数", "质子数", "电子数", "质量数"], "answer": "质子数", "explanation": "原子序数在数值上等于原子的质子数（核电荷数）。"},
                {"type": "choice", "question": "同一周期从左到右，元素性质的变化规律是？", "options": ["金属性增强", "非金属性增强", "原子序数减小", "无明显规律"], "answer": "非金属性增强", "explanation": "同一周期从左到右，金属性逐渐减弱，非金属性逐渐增强。"},
                {"type": "true_false", "question": "判断：水是由水分子构成的，不是由氢气和氧气组成的。", "options": ["正确", "错误"], "answer": "正确", "explanation": "水（H₂O）由水分子构成，水分子由氢原子和氧原子组成，不含氢气和氧气分子。"},
            ]),
            (["化学反应"], [
                {"type": "choice", "question": "化学变化的基本特征是？", "options": ["状态改变", "产生新物质", "颜色改变", "放热"], "answer": "产生新物质", "explanation": "化学变化的本质特征是有新物质生成，其他现象（发光放热、变色等）可作为判断的辅助依据。"},
                {"type": "choice", "question": "下列属于化学变化的是？", "options": ["冰熔化", "蜡烛燃烧", "石块粉碎", "水蒸发"], "answer": "蜡烛燃烧", "explanation": "蜡烛燃烧生成二氧化碳和水等新物质，是化学变化；其余为物理变化。"},
                {"type": "fill_blank", "question": "化学反应遵守质量守恒定律，反应前后原子的种类和____不变。", "options": [], "answer": "数目", "explanation": "质量守恒定律：化学反应前后，原子的种类、数目、质量都不变。"},
            ]),
            (["酸碱盐", "酸碱", "pH"], [
                {"type": "choice", "question": "pH=7的溶液呈？", "options": ["酸性", "碱性", "中性", "无法判断"], "answer": "中性", "explanation": "pH<7呈酸性，pH=7呈中性，pH>7呈碱性。纯水pH约为7。"},
                {"type": "choice", "question": "下列物质属于酸的是？", "options": ["NaOH", "HCl", "NaCl", "CaO"], "answer": "HCl", "explanation": "酸是电离时产生的阳离子全部是H⁺的化合物，HCl（盐酸）是常见的强酸。"},
                {"type": "true_false", "question": "判断：稀盐酸和氢氧化钠溶液混合会发生中和反应，生成盐和水。", "options": ["正确", "错误"], "answer": "正确", "explanation": "HCl + NaOH = NaCl + H₂O，酸碱中和反应生成盐和水。"},
            ]),
            (["原子", "分子", "物质构成"], [
                {"type": "choice", "question": "原子的核心结构是？", "options": ["原子核和核外电子", "质子和中子", "原子核和分子", "电子和中子"], "answer": "原子核和核外电子", "explanation": "原子由带正电的原子核（质子+中子）和带负电的核外电子构成。"},
                {"type": "choice", "question": "保持水的化学性质的最小粒子是？", "options": ["氢原子", "氧原子", "水分子", "质子"], "answer": "水分子", "explanation": "分子是保持物质化学性质的最小粒子，保持水的化学性质的是水分子。"},
                {"type": "fill_blank", "question": "原子中，质子带正电，中子不带电，电子带____电。", "options": [], "answer": "负", "explanation": "原子中质子带正电、中子不带电、电子带负电，整个原子呈电中性。"},
            ]),
            # ========== 物理 ==========
            (["力学", "力", "牛顿"], [
                {"type": "choice", "question": "牛顿第一定律的内容是？", "options": ["力是维持物体运动的原因", "物体在不受力时保持静止或匀速直线运动", "力越大加速度越大", "作用力等于反作用力"], "answer": "物体在不受力时保持静止或匀速直线运动", "explanation": "牛顿第一定律（惯性定律）：一切物体在不受外力时，总保持静止状态或匀速直线运动状态。"},
                {"type": "choice", "question": "下列现象中属于利用惯性的是？", "options": ["系安全带", "跳远时助跑", "限速行驶", "保持车距"], "answer": "跳远时助跑", "explanation": "跳远助跑后起跳，人由于惯性继续向前，能跳得更远。安全带、限速、保持车距是防止惯性带来的危害。"},
                {"type": "true_false", "question": "判断：物体不受力时一定静止。", "options": ["正确", "错误"], "answer": "错误", "explanation": "不受力时，物体可以静止，也可以做匀速直线运动（若原来在运动）。"},
            ]),
            (["电学", "电流", "电路", "欧姆"], [
                {"type": "choice", "question": "欧姆定律的表达式是？", "options": ["I=U/R", "I=UR", "I=U+R", "I=U-R"], "answer": "I=U/R", "explanation": "欧姆定律：导体中的电流与导体两端电压成正比，与导体电阻成反比，即I=U/R。"},
                {"type": "choice", "question": "一段导体两端电压为6V，电阻为3Ω，通过的电流是？", "options": ["2A", "0.5A", "18A", "9A"], "answer": "2A", "explanation": "由I=U/R=6V/3Ω=2A。"},
                {"type": "fill_blank", "question": "串联电路中，电流处处____。", "options": [], "answer": "相等", "explanation": "串联电路中电流处处相等（I=I₁=I₂），电压等于各部分电压之和。"},
            ]),
            (["光学", "光", "反射折射"], [
                {"type": "choice", "question": "光在真空中的传播速度约为？", "options": ["3×10⁵ km/s", "3×10⁸ m/s", "340 m/s", "3×10⁶ m/s"], "answer": "3×10⁸ m/s", "explanation": "光在真空中的传播速度c≈3×10⁸ m/s（即30万千米/秒），是宇宙中最大的速度。"},
                {"type": "choice", "question": "平面镜成像的特点是？", "options": ["像比物小", "倒立的实像", "正立等大的虚像", "像比物大"], "answer": "正立等大的虚像", "explanation": "平面镜成正立、等大、左右相反的虚像，像与物到镜面的距离相等。"},
                {"type": "true_false", "question": "判断：光从空气斜射入水中时，折射角小于入射角。", "options": ["正确", "错误"], "answer": "正确", "explanation": "光从空气（光疏介质）斜射入水（光密介质）时，折射光线靠近法线，折射角小于入射角。"},
            ]),
            (["运动", "速度", "加速度"], [
                {"type": "choice", "question": "速度的国际单位是？", "options": ["km/h", "m/s", "cm/s", "km/s"], "answer": "m/s", "explanation": "速度的国际单位是米/秒（m/s），常用单位还有千米/时（km/h），1 m/s = 3.6 km/h。"},
                {"type": "choice", "question": "匀速直线运动的特点是？", "options": ["速度不断增大", "速度保持不变", "方向不断改变", "加速度不为零"], "answer": "速度保持不变", "explanation": "匀速直线运动中速度大小和方向都不变，加速度为零。"},
                {"type": "fill_blank", "question": "一辆汽车以20 m/s的速度行驶，5秒内通过的路程是____米。", "options": [], "answer": "100", "explanation": "路程=速度×时间=20 m/s×5s=100 m。"},
            ]),
            # ========== 数学 ==========
            (["几何", "三角形", "四边形", "多边形", "圆周", "圆"], [
                {"type": "choice", "question": "三角形内角和等于多少度？", "options": ["90°", "180°", "270°", "360°"], "answer": "180°", "explanation": "任意三角形三个内角的和等于180°，这是三角形的基本性质。"},
                {"type": "choice", "question": "一个三角形三个内角度数之比为1:2:3，这个三角形是？", "options": ["锐角三角形", "直角三角形", "钝角三角形", "等腰三角形"], "answer": "直角三角形", "explanation": "三个角为30°、60°、90°，最大角90°，所以是直角三角形。"},
                {"type": "fill_blank", "question": "直角三角形两直角边分别为3和4，斜边长为____。", "options": [], "answer": "5", "explanation": "勾股定理：c=√(3²+4²)=√25=5。"},
                {"type": "true_false", "question": "判断：圆周率π是一个无理数，约等于3.14159。", "options": ["正确", "错误"], "answer": "正确", "explanation": "π是圆周长与直径的比值，是无理数，常用的近似值为3.14。"},
                {"type": "choice", "question": "n边形内角和公式是？", "options": ["(n-1)×180°", "(n-2)×180°", "n×180°", "(n+2)×180°"], "answer": "(n-2)×180°", "explanation": "n边形内角和=(n-2)×180°，如四边形内角和=(4-2)×180°=360°。"},
            ]),
            (["函数", "一次函数", "反比例", "正比例"], [
                {"type": "choice", "question": "正比例函数 y=kx (k≠0) 的图象是？", "options": ["抛物线", "过原点的直线", "双曲线", "折线"], "answer": "过原点的直线", "explanation": "正比例函数y=kx的图象是一条经过坐标原点(0,0)的直线，k>0时过一三象限。"},
                {"type": "choice", "question": "一次函数 y=2x+3 的图象与y轴的交点是？", "options": ["(0,2)", "(0,3)", "(3,0)", "(2,0)"], "answer": "(0,3)", "explanation": "令x=0，则y=3，图象与y轴交于(0,3)，其中3就是截距b的值。"},
                {"type": "fill_blank", "question": "反比例函数 y=k/x (k≠0) 的图象是____曲线。", "options": [], "answer": "双", "explanation": "反比例函数图象是双曲线，k>0时在一、三象限，k<0时在二、四象限。"},
            ]),
            (["方程", "一元一次", "二元一次", "不等式"], [
                {"type": "choice", "question": "方程 2x+3=7 的解是？", "options": ["x=1", "x=2", "x=3", "x=5"], "answer": "x=2", "explanation": "2x+3=7，2x=4，x=2。验证：2×2+3=7 ✓"},
                {"type": "choice", "question": "解二元一次方程组的基本思想是？", "options": ["画图法", "消元法", "配方", "因式分解"], "answer": "消元法", "explanation": "解二元一次方程组的基本思想是消元（代入消元或加减消元），化二元为一元。"},
                {"type": "fill_blank", "question": "不等式 3x-1>5 的解集是 x>____。", "options": [], "answer": "2", "explanation": "3x-1>5，3x>6，x>2。注意不等式两边同除正数，不等号方向不变。"},
            ]),
            (["一元二次方程", "二次方程"], [
                {"type": "choice", "question": "方程 x²-5x+6=0 的两个根是？", "options": ["x=1, x=6", "x=2, x=3", "x=-2, x=-3", "x=1, x=5"], "answer": "x=2, x=3", "explanation": "(x-2)(x-3)=0，所以x₁=2，x₂=3。也可用求根公式验证。"},
                {"type": "choice", "question": "一元二次方程 ax²+bx+c=0 (a≠0) 的求根公式是？", "options": ["x=(-b±√(b²-4ac))/2a", "x=(-b±√(b²+4ac))/2a", "x=(-b±√(b²-4ac))/a", "x=(-b±√(4ac-b²))/2a"], "answer": "x=(-b±(b²-4ac))/2a".replace("(b²-4ac)", "√(b²-4ac)"), "explanation": "求根公式中判别式Δ=b²-4ac，Δ>0两不等实根，Δ=0两等实根，Δ<0无实根。"},
                {"type": "fill_blank", "question": "一元二次方程 x²-4=0 的解是 x=____。", "options": [], "answer": "±2", "explanation": "x²=4，所以x=2或x=-2，即x=±2。"},
            ]),
            (["二次函数", "抛物线"], [
                {"type": "choice", "question": "二次函数 y=ax²+bx+c (a≠0) 的图象是？", "options": ["直线", "抛物线", "双曲线", "圆"], "answer": "抛物线", "explanation": "二次函数的图象是抛物线，开口方向由a的符号决定。"},
                {"type": "choice", "question": "抛物线 y=ax² 的开口方向取决于？", "options": ["a的大小", "a的符号", "b的值", "c的值"], "answer": "a的符号", "explanation": "a>0开口向上，a<0开口向下。|a|越大开口越小。"},
                {"type": "fill_blank", "question": "二次函数 y=x²-2x-3 的对称轴是直线 x=____。", "options": [], "answer": "1", "explanation": "对称轴x=-b/(2a)=-(-2)/(2×1)=1。"},
            ]),
            (["概率", "统计", "平均数", "中位数"], [
                {"type": "choice", "question": "抛一枚均匀硬币，正面朝上的概率是？", "options": ["1", "1/2", "1/4", "1/3"], "answer": "1/2", "explanation": "硬币有两个面，正面和反面朝上机会均等，概率各为1/2。"},
                {"type": "choice", "question": "一组数据2, 3, 5, 7, 8的中位数是？", "options": ["3", "5", "7", "5.5"], "answer": "5", "explanation": "数据已排序，共5个数，中位数是第3个数即5。"},
                {"type": "fill_blank", "question": "一组数据1, 2, 3, 4的平均数是____。", "options": [], "answer": "2.5", "explanation": "平均数=(1+2+3+4)/4=10/4=2.5。"},
            ]),
            # ========== 语文 ==========
            (["荷塘月色"], [
                {"type": "choice", "question": "《荷塘月色》的作者是？", "options": ["鲁迅", "朱自清", "巴金", "老舍"], "answer": "朱自清", "explanation": "《荷塘月色》是朱自清1927年创作的散文名篇，描绘了月下荷塘的静谧美景。"},
                {"type": "choice", "question": "《荷塘月色》的主要写作手法是？", "options": ["通感修辞", "夸张", "讽刺", "象征对比"], "answer": "通感修辞", "explanation": "荷塘上的月色用通感（如仿佛远处高楼上渺茫的歌声）将视觉、听觉交融，是名篇特色。"},
                {"type": "fill_blank", "question": "《荷塘月色》开头「这几天心里颇不宁静」奠定了全文____的基调。", "options": [], "answer": "淡淡的哀愁", "explanation": "心里颇不宁静反映了作者在特定时代下矛盾复杂的心境，奠定全文朦胧、淡淡的哀愁基调。"},
            ]),
            (["古诗词", "古诗", "唐诗", "唐诗宋词"], [
                {"type": "choice", "question": "「床前明月光」出自哪位诗人？", "options": ["杜甫", "李白", "白居易", "王维"], "answer": "李白", "explanation": "床前明月光，疑是地上霜，出自李白《静夜思》，表达思乡之情。"},
                {"type": "choice", "question": "被誉为「诗圣」的诗人是？", "options": ["李白", "杜甫", "王维", "苏轼"], "answer": "杜甫", "explanation": "杜甫被称为诗圣，其诗被称为诗史，代表作有三吏三别。"},
                {"type": "true_false", "question": "判断：宋词分为婉约派和豪放派两大流派。", "options": ["正确", "错误"], "answer": "正确", "explanation": "宋词主要分婉约派（李清照、柳永）和豪放派（苏轼、辛弃疾）两大流派。"},
            ]),
            (["记叙文"], [
                {"type": "choice", "question": "记叙文的六要素不包括？", "options": ["时间", "地点", "人物", "论据"], "answer": "论据", "explanation": "记叙文六要素：时间、地点、人物、起因、经过、结果。论据是议论文的要素。"},
                {"type": "choice", "question": "记叙文中最常见的叙述方式是？", "options": ["顺叙", "倒叙", "插叙", "补叙"], "answer": "顺叙", "explanation": "顺叙是按照事件发生发展的先后顺序来写，是最基本最常见的叙述方式。"},
                {"type": "fill_blank", "question": "记叙文中，把后发生的事提到前面写的叙述方式叫____。", "options": [], "answer": "倒叙", "explanation": "倒叙是把事件的结局或后面发生的事先写出来，再按顺序叙述。"},
            ]),
            (["议论文"], [
                {"type": "choice", "question": "议论文的三要素是？", "options": ["论点、论据、论证", "时间、地点、人物", "起因、经过、结果", "标题、开头、结尾"], "answer": "论点、论据、论证", "explanation": "议论文三要素：论点（观点）、论据（支撑观点的材料）、论证（用论据证明论点的过程）。"},
                {"type": "choice", "question": "下列属于道理论据的是？", "options": ["统计数据", "名人名言", "历史事件", "亲身经历"], "answer": "名人名言", "explanation": "论据分事实论据（事例、数据）和道理论据（名言警句、科学原理）。名人名言属道理论据。"},
                {"type": "true_false", "question": "判断：议论文的中心论点只能出现在文章开头。", "options": ["正确", "错误"], "answer": "错误", "explanation": "中心论点可在开头提出，也可在中间或结尾归纳，甚至标题即为论点。"},
            ]),
            # ========== 英语 ==========
            (["时态", "tense", "现在时", "过去时", "进行时", "完成时", "现在完成时"], [
                {"type": "choice", "question": "Which sentence uses the present perfect tense?", "options": ["I eat apples.", "I ate apples.", "I have eaten apples.", "I am eating apples."], "answer": "I have eaten apples.", "explanation": "现在完成时结构为have/has+过去分词，强调过去动作对现在的影响。"},
                {"type": "choice", "question": "「Yesterday」常与哪种时态连用？", "options": ["一般现在时", "一般过去时", "现在进行时", "现在完成时"], "answer": "一般过去时", "explanation": "yesterday是明确的过去时间状语，常与一般过去时连用。"},
                {"type": "fill_blank", "question": "Fill: She ____ (go) to school every day. (用一般现在时)", "options": [], "answer": "goes", "explanation": "主语She是第三人称单数，一般现在时动词加-s/-es，go→goes。"},
            ]),
            (["从句", "clause", "定语从句", "宾语从句"], [
                {"type": "choice", "question": "在句子 'I know that he is a teacher.' 中，that 引导的是？", "options": ["定语从句", "宾语从句", "状语从句", "主语从句"], "answer": "宾语从句", "explanation": "that引导的从句作动词know的宾语，是宾语从句，that在宾语从句中不充当成分。"},
                {"type": "choice", "question": "定语从句中，修饰人并在从句中作主语的关系代词常用？", "options": ["which", "who", "whose", "where"], "answer": "who", "explanation": "先行词指人且在从句中作主语时，关系代词用who或that（如The man who lives here is my teacher）。"},
                {"type": "fill_blank", "question": "This is the book ____ I bought yesterday. (填关系代词)", "options": [], "answer": "that/which", "explanation": "先行词book指物，在从句中作bought的宾语，关系代词用that或which（可省略）。"},
            ]),
        ]



    def _math_questions(self, topic):
        import random
        from fractions import Fraction
        random.seed(hash(topic) & 0xFFFF)
        qs = []
        has_frac = "分数" in topic
        for i in range(5):
            if has_frac:
                n1, d1 = random.randint(1, 5), random.randint(2, 9)
                n2, d2 = random.randint(1, 5), random.randint(2, 9)
                q = f"计算 {n1}/{d1} + {n2}/{d2} = ?"
                ans = Fraction(n1, d1) + Fraction(n2, d2)
                ans_s = f"{ans.numerator}/{ans.denominator}" if ans.denominator != 1 else str(ans.numerator)
                wrong = [f"{n1+n2}/{max(d1,d2)}", f"{n1+n2}/{d1+d2}", f"{n1*n2}/{d1*d2}"]
                opts = list(set([ans_s] + [w for w in wrong if w != ans_s][:3]))
                while len(opts) < 4:
                    w = f"{random.randint(1,9)}/{random.randint(2,9)}"
                    if w not in opts:
                        opts.append(w)
                random.shuffle(opts)
                qs.append({
                    "type": "choice", "question": q,
                    "options": [f"{chr(65+j)}. {o}" for j, o in enumerate(opts)],
                    "answer": f"{chr(65+opts.index(ans_s))}. {ans_s}",
                    "explanation": f"同分母分数相加，分子相加分母不变；异分母先通分。{n1}/{d1}+{n2}/{d2}={ans_s}。",
                })
            else:
                a, b = random.randint(12, 89), random.randint(12, 89)
                if a < b:
                    a, b = b, a
                ans = a + b
                q = f"计算 {a} + {b} = ?"
                wrong = []
                while len(wrong) < 3:
                    w = ans + random.choice(range(-20, 21))
                    if w != ans and w >= 0 and w not in wrong:
                        wrong.append(w)
                opts = [ans] + wrong
                random.shuffle(opts)
                qs.append({
                    "type": "choice", "question": q,
                    "options": [f"{chr(65+j)}. {o}" for j, o in enumerate(opts)],
                    "answer": f"{chr(65+opts.index(ans))}. {ans}",
                    "explanation": f"{a} + {b} = {ans}。注意进位的正确处理。",
                })
        return qs

    def _chinese_questions(self, topic):
        return [
            {
                "type": "choice",
                "question": f"下列关于「{topic}」的表述，最准确的是？",
                "options": ["需要结合具体语境理解", "只需字面意思即可", "与作者意图无关", "可以随意理解"],
                "answer": "需要结合具体语境理解",
                "explanation": "语文学习强调结合语境和作者意图来理解内容。",
            },
            {
                "type": "choice",
                "question": f"学习「{topic}」时，下列哪种方法最有助于深入理解？",
                "options": ["反复诵读并结合语境分析", "只看一遍就能掌握", "抄写生字词就可以", "背诵答案即可"],
                "answer": "反复诵读并结合语境分析",
                "explanation": "多读多思是语文学习的基本方法，结合语境分析能加深理解。",
            },
            {
                "type": "fill_blank",
                "question": f"请用一句话概括「{topic}」的主要内容：______。",
                "options": [],
                "answer": f"本文围绕{topic}展开，表达了作者的思想感情和主要观点。",
                "explanation": f"概括内容需要抓住{topic}的核心要点。",
            },
            {
                "type": "true_false",
                "question": f"判断：「{topic}」的学习只需要记住知识点就够了。",
                "options": ["正确", "错误"],
                "answer": "错误",
                "explanation": "语文学习需要理解、感悟和运用，仅记住知识点是不够的。",
            },
            {
                "type": "choice",
                "question": f"下列哪个词语最适合用来描述「{topic}」？",
                "options": ["生动形象、富有感染力", "干瘦枯燥、条理不清", "词不达意、语义不明", "重复啰嗦、缺乏新意"],
                "answer": "生动形象、富有感染力",
                "explanation": "词语的选择应当符合语境，生动形象的表达更有说服力。",
            },
        ]

    def _english_questions(self, topic):
        return [
            {
                "type": "choice",
                "question": 'Which sentence about "' + topic + '" is correct?',
                "options": ["It is important to understand the concept in context.", "Memorization alone is sufficient.", "It has no practical application.", "It should be skipped in exams."],
                "answer": "It is important to understand the concept in context.",
                "explanation": "Understanding concepts in context is key to language learning.",
            },
            {
                "type": "fill_blank",
                "question": 'Fill in the blank: The key to learning "' + topic + '" is to ______ regularly.',
                "options": [],
                "answer": "practice",
                "explanation": "Regular practice is essential for mastering any language topic.",
            },
            {
                "type": "true_false",
                "question": 'True or False: "' + topic + '" is only useful for exams.',
                "options": ["True", "False"],
                "answer": "False",
                "explanation": "Language knowledge applies to real-world communication, not just exams.",
            },
            {
                "type": "choice",
                "question": 'What is the best way to practice "' + topic + '"?',
                "options": ["Use it in sentences and conversations", "Only read about it", "Copy answers from others", "Wait until the exam"],
                "answer": "Use it in sentences and conversations",
                "explanation": "Active usage in context reinforces learning.",
            },
            {
                "type": "choice",
                "question": 'Which word is most closely related to "' + topic + '"?',
                "options": ["comprehension", "irrelevant", "unnecessary", "optional"],
                "answer": "comprehension",
                "explanation": "Understanding and comprehension are central to mastering any topic.",
            },
        ]

    def _science_questions(self, topic):
        return [
            {
                "type": "choice",
                "question": f"关于「{topic}」，下列说法正确的是？",
                "options": ["需要通过观察和实验来验证", "只需凭空想象", "与实际现象无关", "可以随意解释"],
                "answer": "需要通过观察和实验来验证",
                "explanation": "科学知识来源于观察和实验，需要实践验证。",
            },
            {
                "type": "choice",
                "question": f"学习「{topic}」最重要的方法是？",
                "options": ["理解原理并动手实验", "死记公式", "背诵定义", "猜测结果"],
                "answer": "理解原理并动手实验",
                "explanation": "科学学习强调理论结合实践，动手实验能加深理解。",
            },
            {
                "type": "fill_blank",
                "question": f"「{topic}」的核心原理是：______。",
                "options": [],
                "answer": "通过观察、实验和推理总结出的规律",
                "explanation": "科学原理是对自然现象规律的总结。",
            },
            {
                "type": "true_false",
                "question": f"判断：「{topic}」可以通过实验来验证。",
                "options": ["正确", "错误"],
                "answer": "正确",
                "explanation": "科学理论可以通过实验来验证其正确性。",
            },
            {
                "type": "choice",
                "question": f"下列哪项属于科学探究「{topic}」的基本步骤？",
                "options": ["提出问题→假设→实验→结论", "直接给出结论", "只看书本", "把问题留给老师"],
                "answer": "提出问题→假设→实验→结论",
                "explanation": "科学探究遵循问题→假设→实验→结论的基本流程。",
            },
        ]

    def _exercise_html(self, q):
        qtype = q.get("type", "choice")
        stem = (q.get("question") or "").replace("'", "\'")
        opts = q.get("options") or []
        answer = (q.get("answer") or "").replace("'", "\'")
        if qtype in ("choice", "true_false") and opts:
            btns = ""
            for o in opts:
                safe = o.replace("'", "\'")
                btns += "<button class='eo' data-a='" + safe + "' onclick='ep(this)'>" + o + "</button>"
            return (
                "<style>.eq{width:100%;height:100%;box-sizing:border-box;padding:32px 40px;background:#f0fdf4;font-family:'Microsoft YaHei',sans-serif;overflow-y:auto}"
                ".eq h3{color:#166534;margin:0 0 16px;font-size:20px;line-height:1.6}"
                ".eo{display:block;width:100%;margin:8px 0;padding:14px 18px;border:2px solid #bbf7d0;border-radius:10px;background:#fff;font-size:17px;cursor:pointer;transition:.2s;text-align:left}"
                ".eo:hover{border-color:#22c55e}.eo.ok{background:#dcfce7;border-color:#16a34a}.eo.bad{background:#fef2f2;border-color:#ef4444}</style>"
                "<div class='eq'><h3>" + stem + "</h3>" + btns
                + "<input type='hidden' id='ea' value='" + answer + "'></div>"
                + "<script>function ep(b){var a=document.getElementById('ea').value;"
                "document.querySelectorAll('.eo').forEach(function(e){e.classList.remove('ok','bad')});"
                "if(b.getAttribute('data-a')==a||b.textContent==a){b.classList.add('ok')}else{b.classList.add('bad');"
                "document.querySelectorAll('.eo').forEach(function(e){if(e.getAttribute('data-a')==a||e.textContent==a)e.classList.add('ok')})}}"
                + "</script>"
            )
        if qtype == "fill_blank":
            return (
                "<style>.eq{width:100%;height:100%;box-sizing:border-box;padding:32px 40px;background:#f0fdf4;font-family:'Microsoft YaHei',sans-serif;display:flex;flex-direction:column;justify-content:center}"
                ".eq h3{color:#166534;margin:0 0 20px;font-size:20px;line-height:1.6}"
                ".ei{padding:14px 18px;border:2px solid #bbf7d0;border-radius:10px;font-size:18px;width:80%;margin-bottom:16px}"
                ".eb{padding:12px 32px;background:#16a34a;color:#fff;border:none;border-radius:10px;font-size:17px;cursor:pointer}"
                ".ef{margin-top:16px;font-size:15px;display:none}</style>"
                "<div class='eq'><h3>" + stem + "</h3>"
                + "<input class='ei' id='fu' placeholder='请输入答案'>"
                + "<button class='eb' id='fb'>提交</button>"
                + "<p class='ef' id='fr'></p></div>"
                + "<script>(function(){var ans='" + answer.replace("'", "") + "';"
                "document.getElementById('fb').addEventListener('click',function(){"
                "var u=document.getElementById('fu').value.trim().toLowerCase();"
                "var a=ans.toLowerCase();var f=document.getElementById('fr');"
                "f.style.display='block';"
                "if(u.indexOf(a)>=0||a.indexOf(u)>=0){f.style.color='#16a34a';f.textContent='✓ 回答正确！'}"
                "else{f.style.color='#ef4444';f.textContent='✗ 正确答案：'+ans}})})();</script>"
            )
        return "<div class='eq' style='width:100%;height:100%;padding:32px;background:#f0fdf4;font-family:sans-serif'><h3 style='color:#166534'>" + stem + "</h3></div>"

    def _fallback_lesson_plan(self, title, subject, grade, objectives, duration):
        t = title or "大单元教案"
        subj = (subject or "").strip()
        prof = self._lesson_plan_profile(subj)
        new_dur = max(10, duration - 20)
        practice_dur = max(8, duration // 4)
        return {
            "title": t,
            "objectives": objectives or prof["objectives"](t),
            "key_points": prof["key_points"](t),
            "difficulties": prof["difficulties"](t),
            "phases": [
                {"name": "导入", "duration": 5, "activities": [prof["intro"](t)], "teacher_actions": ["创设情境，激发兴趣。", "提出核心问题。"], "student_actions": ["观察思考。", "联系已有经验。"], "resources": prof["intro_resources"]},
                {"name": "新授", "duration": new_dur, "activities": prof["new_activities"](t), "teacher_actions": prof["new_teacher"], "student_actions": prof["new_student"], "resources": prof["new_resources"]},
                {"name": "练习巩固", "duration": practice_dur, "activities": prof["practice"](t), "teacher_actions": ["巡视指导，个别辅导。"], "student_actions": prof["practice_student"], "resources": prof["practice_resources"]},
                {"name": "总结", "duration": 5, "activities": [prof["summary"](t)], "teacher_actions": ["梳理知识脉络，提炼方法。"], "student_actions": ["回顾反思，记录收获。"], "resources": ["板书", "思维导图"]},
            ],
            "homework": prof["homework"](t),
            "reflection": f"根据课堂反馈与学生掌握情况，调整「{t}」后续教学的深度、广度与练习分层策略。",
        }

    def _lesson_plan_profile(self, subject: str) -> dict:
        s = subject
        profiles = {
            "数学": {
                "objectives": lambda t: [f"理解「{t}」的概念内涵与几何或代数意义", f"掌握「{t}」的基本公式与运算法则", "能运用所学知识分析并解决实际问题"],
                "key_points": lambda t: [f"「{t}」的定义与核心性质", "公式推导与规范书写"],
                "difficulties": lambda t: [f"「{t}」的灵活运用与变形", "数形结合思想的建立"],
                "intro": lambda t: f"借助生活实例或已有知识，引出「{t}」的研究必要性。",
                "new_activities": lambda t: [f"通过探究活动归纳「{t}」的概念与性质。", "推导公式并分析适用条件。"],
                "new_teacher": ["引导探究，板书推导过程。", "组织小组讨论。"],
                "new_student": ["动手操作或画图探究。", "小组合作归纳结论。"],
                "intro_resources": ["课件", "实物教具", "几何画板"],
                "new_resources": ["学案", "探究任务单", "动态演示"],
                "practice": lambda t: ["基础题巩固概念。", "变式训练提升能力。", "实际问题应用。"],
                "practice_student": ["独立完成，规范步骤。", "同桌互批，错题订正。"],
                "practice_resources": ["分层练习", "答题卡"],
                "summary": lambda t: f"梳理「{t}」的知识结构图，提炼解题方法与易错点。",
                "homework": lambda t: [f"完成「{t}」分层作业（基础+提升）。", "整理本节易错题集。"],
            },
            "物理": {
                "objectives": lambda t: [f"理解「{t}」的物理意义与适用条件", "掌握相关公式并能进行简单计算", "经历实验探究过程，培养科学思维"],
                "key_points": lambda t: [f"「{t}」的概念建立与公式表达", "实验现象的观察与分析"],
                "difficulties": lambda t: [f"「{t}」物理模型的构建", "实验方案的设计与数据分析"],
                "intro": lambda t: f"通过演示实验或生活现象，引发对「{t}」的思考。",
                "new_activities": lambda t: ["分组实验探究规律。", "分析实验数据，归纳结论。"],
                "new_teacher": ["演示关键实验，强调安全。", "指导小组实验，引导分析。"],
                "new_student": ["分组实验，记录数据。", "分析数据，得出结论。"],
                "intro_resources": ["演示器材", "课件", "视频"],
                "new_resources": ["学生实验器材", "数据记录表"],
                "practice": lambda t: ["基础概念辨析。", "公式应用计算。", "实验数据分析题。"],
                "practice_student": ["独立解题，规范作图。", "小组互查实验报告。"],
                "practice_resources": ["练习卷", "实验报告单"],
                "summary": lambda t: f"构建「{t}」的知识网络，强调实验方法与物理思想。",
                "homework": lambda t: [f"完成「{t}」课后练习。", "撰写实验探究报告。"],
            },
        }
        # 化学/生物共用理科探究模板
        sci = {
            "objectives": lambda t: [f"理解「{t}」的基本概念与原理", "掌握核心知识并能解释相关现象", "培养实验观察与科学探究能力"],
            "key_points": lambda t: [f"「{t}」的核心概念与特征", "实验现象的观察与解释"],
            "difficulties": lambda t: [f"「{t}」微观机制的理解", "知识在真实情境中的迁移应用"],
            "intro": lambda t: f"通过实验现象或生活实例，引出「{t}」的探究问题。",
            "new_activities": lambda t: ["实验观察与操作。", "小组讨论归纳知识要点。"],
            "new_teacher": ["组织实验，强调规范操作。", "引导分析现象背后的原理。"],
            "new_student": ["动手实验，如实记录。", "讨论交流，形成结论。"],
            "intro_resources": ["实验器材", "课件", "标本/模型"],
            "new_resources": ["实验材料", "学习单"],
            "practice": lambda t: ["概念辨析与判断。", "现象解释与应用。"],
            "practice_student": ["独立完成练习。", "小组互评实验记录。"],
            "practice_resources": ["练习卡", "实验记录册"],
            "summary": lambda t: f"梳理「{t}」的知识体系，强调科学方法与探究思路。",
            "homework": lambda t: [f"完成「{t}」巩固练习。", "预习下一节内容并完成预习单。"],
        }
        for k in ("化学", "生物"):
            profiles[k] = sci
        profiles["语文"] = {
            "objectives": lambda t: [f"品味「{t}」的语言特色与表达技巧", "理解文章主旨与作者情感", "学习并运用相关的写作方法"],
            "key_points": lambda t: [f"「{t}」的文本内容与结构梳理", "关键语句的赏析与理解"],
            "difficulties": lambda t: [f"「{t}」深层意蕴与作者情感的体悟", "写作手法在表达中的迁移运用"],
            "intro": lambda t: f"借助背景介绍或朗读导入，唤起对「{t}」的阅读期待。",
            "new_activities": lambda t: ["初读感知，整体把握文意。", "精读品味，赏析关键语段。"],
            "new_teacher": ["范读指导，组织品析。", "点拨赏析方法。"],
            "new_student": ["朗读体会，圈点批注。", "小组交流赏析心得。"],
            "intro_resources": ["课件", "背景资料", "音频朗读"],
            "new_resources": ["文本", "批注学习单"],
            "practice": lambda t: ["仿写练习。", "片段赏析与表达。"],
            "practice_student": ["独立完成仿写。", "分享交流，互评互改。"],
            "practice_resources": ["仿写学习单", "评价量表"],
            "summary": lambda t: f"总结「{t}」的写法与主旨，提炼可借鉴的表达技巧。",
            "homework": lambda t: [f"围绕「{t}」完成读写结合小练笔。", "积累本文好词好句。"],
        }
        profiles["英语"] = {
            "objectives": lambda t: [f"掌握「{t}」相关核心词汇与句型", "能在真实情境中运用所学进行交流", "提升听、说、读、写综合语言能力"],
            "key_points": lambda t: [f"「{t}」的核心词汇与目标句型", "语言功能的得体运用"],
            "difficulties": lambda t: [f"「{t}」相关语法结构的正确使用", "在真实交际中的灵活表达"],
            "intro": lambda t: f"通过歌曲、游戏或情境对话导入「{t}」话题。",
            "new_activities": lambda t: ["词汇与句型学习。", "情境对话操练与角色扮演。"],
            "new_teacher": ["创设情境，示范句型。", "组织pair work与group work。"],
            "new_student": ["跟读模仿，记忆词汇。", "结对操练，大胆表达。"],
            "intro_resources": ["课件", "音频视频", "单词卡"],
            "new_resources": ["对话任务单", "角色卡片"],
            "practice": lambda t: ["词汇句型巩固。", "情境交际任务。"],
            "practice_student": ["完成听力与填空。", "小组表演对话。"],
            "practice_resources": ["练习单", "评价表"],
            "summary": lambda t: f"回顾「{t}」核心语言知识，梳理交际策略。",
            "homework": lambda t: [f"完成「{t}」听读作业。", "用目标句型写一段对话。"],
        }
        profiles["历史"] = {
            "objectives": lambda t: [f"了解「{t}」的基本史实与发展脉络", "分析历史事件的因果关系与影响", "培养历史思维与家国情怀"],
            "key_points": lambda t: [f"「{t}」的关键事件、人物与时间", "历史发展规律与时代特征"],
            "difficulties": lambda t: [f"对「{t}」历史现象的多角度分析", "史论结合，以史为鉴"],
            "intro": lambda t: f"通过史料、图片或视频导入「{t}」的时代背景。",
            "new_activities": lambda t: ["梳理时间线与重大事件。", "研读史料，分析因果关系。"],
            "new_teacher": ["提供史料，引导分析。", "组织讨论，启发思考。"],
            "new_student": ["阅读史料，做时间轴。", "小组讨论，发表见解。"],
            "intro_resources": ["课件", "历史地图", "史料摘录"],
            "new_resources": ["史料学习单", "时间轴模板"],
            "practice": lambda t: ["史实梳理填空。", "材料分析题。"],
            "practice_student": ["独立完成基础题。", "小组研讨材料题。"],
            "practice_resources": ["练习卷", "材料研读单"],
            "summary": lambda t: f"构建「{t}」的知识框架，总结历史启示。",
            "homework": lambda t: [f"完成「{t}」巩固练习。", "撰写一段历史小短评。"],
        }
        profiles["地理"] = {
            "objectives": lambda t: [f"认识「{t}」的空间分布与基本特征", "理解各地理要素的相互关系", "树立人地协调与可持续发展观念"],
            "key_points": lambda t: [f"「{t}」的位置、分布与主要特征", "自然与人文地理要素的相互作用"],
            "difficulties": lambda t: [f"「{t}」空间格局的综合分析", "读图分析与地理推理"],
            "intro": lambda t: f"借助地图、卫星图或景观图导入「{t}」。",
            "new_activities": lambda t: ["读图分析空间分布。", "小组探究地理要素关系。"],
            "new_teacher": ["指导读图方法。", "组织探究活动。"],
            "new_student": ["读图标注，提取信息。", "小组合作，归纳特征。"],
            "intro_resources": ["课件", "地图", "景观图片"],
            "new_resources": ["空白地图", "探究任务单"],
            "practice": lambda t: ["读图填图训练。", "综合分析题。"],
            "practice_student": ["独立完成读图题。", "小组研讨分析题。"],
            "practice_resources": ["练习图册", "分析学习单"],
            "summary": lambda t: f"整理「{t}」知识结构，强调人地关系与可持续发展。",
            "homework": lambda t: [f"完成「{t}」读图与练习。", "调查身边的地理现象。"],
        }
        if s in profiles:
            return profiles[s]
        # 通用模板
        return {
            "objectives": lambda t: [f"理解「{t}」的核心内容与基本要求", "掌握关键知识与基本方法", "培养分析思维与合作探究能力"],
            "key_points": lambda t: [f"「{t}」的核心知识建构", "方法与技能的训练"],
            "difficulties": lambda t: [f"「{t}」的深入理解与灵活运用", "知识的迁移与综合"],
            "intro": lambda t: f"创设情境，引出「{t}」的学习主题。",
            "new_activities": lambda t: [f"围绕「{t}」进行讲解与互动探究。"],
            "new_teacher": ["讲解引导，组织探究。"],
            "new_student": ["主动思考，合作探究。"],
            "intro_resources": ["课件", "情境素材"],
            "new_resources": ["学习单", "探究材料"],
            "practice": lambda t: ["分层练习巩固。", "互评与订正。"],
            "practice_student": ["独立完成，规范作答。"],
            "practice_resources": ["练习卡"],
            "summary": lambda t: f"梳理「{t}」知识结构，提炼重点方法。",
            "homework": lambda t: [f"完成「{t}」巩固作业。", "预习下节内容。"],
        }

    def _fallback_essay_grade(self, essay_text, total_score):
        text = essay_text or ""
        char_count = len(text)
        import re as _re2
        sentences = [s.strip() for s in _re2.split(r"[。！？]", text) if s.strip()]
        sent_count = len(sentences)
        has_dialog = "“" in text or "说" in text
        has_detail = any(w in text for w in ("有一次", "记得", "那天", "当时", "忽然", "只见"))
        avg_sent = char_count / max(sent_count, 1)
        score_ratio = 0.82 if avg_sent > 25 else 0.74
        score = max(1, int(total_score * score_ratio))
        annotations = []
        if has_detail:
            for kw in ("有一次", "记得", "那天", "当时"):
                pos = text.find(kw)
                if pos >= 0:
                    snippet = text[max(0,pos-3):pos+12]
                    annotations.append({"text": snippet, "comment": "这里用具体事例展开，增加了文章的真实感。", "type": "good"})
                    break
        if char_count < 100:
            annotations.append({"text": text[:20], "comment": "文章字数偏少，建议增加具体描写。", "type": "error"})
        strengths = []
        weaknesses = []
        suggestions = []
        if has_detail:
            strengths.append("能用具体事例展开叙述，增加了文章的感染力。")
        else:
            weaknesses.append("缺乏具体事例和细节描写，内容较空洞。")
            suggestions.append("增加一到两个具体事例，展开细节描写。")
        if has_dialog:
            strengths.append("运用了对话描写，使人物形象更加鲜活。")
        else:
            suggestions.append("可以加入对话描写，让人物更鲜活。")
        if sent_count <= 2:
            weaknesses.append("句子偏少，结构较单谬。")
            suggestions.append("增加句子数量，丰富文章层次。")
        if avg_sent > 40:
            weaknesses.append("部分句子较长，建议适当断句。")
            suggestions.append("将过长的句子拆分为短句，提高可读性。")
        content_ratio = 0.32 if has_detail else 0.25
        content_s = int(total_score * content_ratio)
        structure_s = int(total_score * 0.22)
        language_s = int(total_score * 0.18)
        writing_s = score - content_s - structure_s - language_s
        if not strengths:
            strengths = ["主题明确，有基本的表达。"]
        if not weaknesses:
            weaknesses = ["可以在细节上进一步丰富。"]
        if not suggestions:
            suggestions = ["继续保持认真观察和真诚表达。"]
        level = "优秀" if score_ratio > 0.80 else ("良好" if score_ratio > 0.72 else "中等")
        return {
            "total_score": score,
            "scores": {
                "content": {"score": content_s, "max": int(total_score * 0.3), "comment": "内容较为充实。" if has_detail else "内容基本完整，建议增加细节。"},
                "structure": {"score": structure_s, "max": int(total_score * 0.25), "comment": "结构较清晰。" if sent_count > 2 else "结构较为单谬，建议增加层次。"},
                "language": {"score": language_s, "max": int(total_score * 0.25), "comment": "表达较通顺。" if avg_sent <= 40 else "部分句子较长，可适当断句。"},
                "writing": {"score": writing_s, "max": int(total_score * 0.2), "comment": "书写规范尚可。"},
            },
            "overall_comment": "作文围绕主题展开，" + ("能用具体事例进行叙述，" if has_detail else "但缺乏具体细节，") + "表达有一定的真实感。" + ("建议继续加强细节描写和语言表现力，让文章更有感染力。" if not has_detail else "建议在语言精炼和结构层次上进一步提升。"),
            "strengths": strengths,
            "weaknesses": weaknesses,
            "suggestions": suggestions,
            "annotations": annotations,
            "level": level,
        }

    def _fallback_exam(self, subject, grade, knowledge_points, difficulty, question_types, count, total_score):
        total = max(1, min(count or 10, 20))
        each = max(1, total_score // max(total, 1))
        subj = subject or "综合"
        kp = "、".join(knowledge_points) if knowledge_points else "基础知识"
        bank = self._question_bank(kp, subj)
        if not bank:
            bank = self._generic_question_bank(kp, subj)
        questions = []
        for idx in range(total):
            q = dict(bank[idx % len(bank)])
            q["id"] = idx + 1
            q["type"] = q.get("type", (question_types or ["choice"])[0])
            q["score"] = each
            q["difficulty"] = difficulty if isinstance(difficulty, str) else ["easy", "medium", "hard"][idx % 3]
            q["content"] = q.pop("question", None) or q.get("content", "")
            q["analysis"] = q.get("explanation", q.get("analysis", ""))
            if "explanation" in q:
                q.pop("explanation", None)
            if "html" in q:
                q.pop("html", None)
            questions.append(q)
        return {"title": f"{subj}{grade or ''}智能试卷", "questions": questions}

    def _courseware_category(self, prompt: str) -> str:
        prompt = self._repair_text(prompt)
        if any(k in prompt for k in ["圆柱", "圆柱的体积", "体积公式", "底面积", "高"]):
            return "cylinder"
        return "general"

    def _courseware_shell(self, title: str, subtitle: str, body: str, footer_left: str = "") -> str:
        title_html = html_lib.escape(title)
        subtitle_html = html_lib.escape(subtitle)
        footer_html = html_lib.escape(footer_left)
        return f"""<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,PingFang SC,sans-serif;color:#143b31;'>
  <style>
    .zj-top{{position:absolute;left:36px;right:36px;top:24px;height:64px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #d9e7dc;}}
    .zj-top h2{{margin:0 0 6px;font-size:26px;color:#00543d;}}
    .zj-top p{{margin:0;color:#6b7f76;font-size:14px;}}
    .zj-badge{{padding:8px 14px;border-radius:18px;background:#e8f7ef;color:#007a52;font-size:13px;font-weight:700;}}
    .zj-stage{{position:absolute;left:48px;right:48px;top:110px;bottom:64px;background:#fff;border:1px solid #dce8de;border-radius:16px;box-shadow:0 12px 30px rgba(15,84,61,.08);overflow:hidden;}}
    .zj-footer{{position:absolute;left:36px;right:36px;bottom:20px;display:flex;align-items:center;justify-content:space-between;color:#6b7f76;font-size:13px;}}
    .zj-chip{{display:inline-flex;align-items:center;gap:6px;padding:10px 14px;border-radius:999px;border:1px solid #cfe0d3;background:#fff;color:#00543d;font-size:13px;cursor:pointer;}}
    .zj-card{{background:#fff;border:1px solid #dce8de;border-radius:14px;box-shadow:0 10px 24px rgba(15,84,61,.06);}}
    .zj-btn{{border:none;border-radius:12px;padding:10px 16px;background:#00543d;color:#fff;cursor:pointer;font-size:14px;}}
    .zj-btn.alt{{background:#fff;color:#00543d;border:1px solid #cfe0d3;}}
    .zj-pill{{padding:6px 12px;border-radius:999px;background:#ecfdf5;color:#00543d;font-size:12px;}}
    .zj-grid2{{display:grid;grid-template-columns:1fr 1fr;gap:16px;}}
    .zj-grid3{{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;}}
  </style>
  <div class='zj-top'>
    <div><h2>{title_html}</h2><p>{subtitle_html}</p></div>
    <div class='zj-badge'>AI生成</div>
  </div>
  <div class='zj-stage'>{body}</div>
  <div class='zj-footer'><div>{footer_html}</div><div>页面内可点击交互</div></div>
</div>"""

    def _fallback_courseware(self, prompt: str, subject: str, grade: str, page_count: int) -> dict:
        prompt = self._repair_text(prompt)
        if self._courseware_category(prompt) == "cylinder":
            return self._fallback_cylinder_courseware(prompt, subject, grade, page_count)
        return self._fallback_general_courseware(prompt, subject, grade, page_count)

    def _normalize_courseware_result(self, result: dict, prompt: str, subject: str, grade: str, page_count: int, aspect_ratio: str) -> dict | None:
        if not isinstance(result, dict):
            return None
        pages = result.get("pages")
        if not isinstance(pages, list) or len(pages) < 5:
            return None
        normalized_pages = []
        for page in pages:
            if not isinstance(page, dict):
                continue
            content = page.get("content")
            if not isinstance(content, str):
                continue
            cleaned = content.replace("100vh", "100%").replace("100vw", "100%")
            if not cleaned.strip().lower().startswith("<div"):
                cleaned = f"<div style='width:100%;height:100%;position:relative;overflow:hidden;'>{cleaned}</div>"
            normalized_pages.append({
                "type": page.get("type") or "content",
                "title": self._repair_text(str(page.get("title") or "")),
                "content": cleaned,
                "notes": self._repair_text(str(page.get("notes") or "")),
            })
        if len(normalized_pages) < 5:
            return None
        return {
            "title": self._repair_text(str(result.get("title") or prompt[:24] or "课件")),
            "summary": self._repair_text(str(result.get("summary") or "")),
            "tags": [self._repair_text(str(tag)) for tag in (result.get("tags") or []) if str(tag).strip()],
            "pages": normalized_pages[:max(5, min(page_count, len(normalized_pages)))],
            "aspect_ratio": aspect_ratio,
            "subject": subject,
            "grade": grade,
        }

    def _courseware_topic(self, prompt: str) -> str:
        prompt = self._repair_text(prompt)
        text = prompt.lower()
        if any(k in prompt for k in ["地球公转", "四季", "春分", "夏至", "秋分", "冬至", "昼夜长短", "太阳直射"]) or any(k in text for k in ["orbit", "season"]):
            return "orbit"
        if any(k in prompt for k in ["圆柱", "体积", "底面积", "圆锥", "长方体"]):
            return "cylinder"
        return "general"

    def _courseware_shell_clean(self, title: str, subtitle: str, body: str, footer_left: str = "") -> str:
        title_html = html_lib.escape(title)
        subtitle_html = html_lib.escape(subtitle)
        footer_html = html_lib.escape(footer_left)
        return (
            "<div style='width:100%;height:100%;position:relative;overflow:hidden;background:#f6fbf7;font-family:Microsoft YaHei,PingFang SC,sans-serif;color:#143b31;'>"
            "<style>"
            ".zj-top{position:absolute;left:28px;right:28px;top:16px;height:42px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #c9dacc;}"
            ".zj-top h2{margin:0;font-size:21px;line-height:1.15;color:#004737;font-weight:700;}"
            ".zj-top p{margin:3px 0 0;color:#617971;font-size:12px;}"
            ".zj-badge{width:78px;height:28px;border-radius:999px;border:1px solid #c9dacc;background:#fff;color:#004737;font-size:12px;font-weight:700;display:flex;align-items:center;justify-content:center;}"
            ".zj-stage{position:absolute;left:20px;right:20px;top:70px;bottom:20px;background:#fff;border:1px solid #c9dacc;border-radius:16px;box-shadow:0 16px 34px rgba(0,71,55,.08);overflow:auto;}"
            ".zj-footer{display:none;}"
            ".zj-chip{display:inline-flex;align-items:center;gap:6px;padding:10px 14px;border-radius:999px;border:1px solid #cfe0d3;background:#fff;color:#00543d;font-size:13px;cursor:pointer;}"
            ".zj-card{background:#fff;border:1px solid #dce8de;border-radius:14px;box-shadow:0 10px 24px rgba(15,84,61,.06);}"
            ".zj-btn{border:none;border-radius:12px;padding:10px 16px;background:#00543d;color:#fff;cursor:pointer;font-size:14px;}"
            ".zj-btn.alt{background:#fff;color:#00543d;border:1px solid #cfe0d3;}"
            ".zj-pill{padding:6px 12px;border-radius:999px;background:#ecfdf5;color:#00543d;font-size:12px;}"
            ".zj-grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px;}"
            ".zj-grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;}"
            ".season-btn{height:46px;border-radius:13px;border:1px solid #d9e7dc;background:#fff;color:#516b61;display:flex;align-items:center;justify-content:center;gap:6px;font-weight:700;cursor:pointer;transition:all .22s ease;box-shadow:0 4px 12px rgba(15,84,61,.05);user-select:none;}"
            ".season-btn.active{border-color:#00a870;background:#ecfdf5;color:#00543d;box-shadow:0 10px 18px rgba(0,168,112,.10);}"
            ".orbit-wrap{position:relative;height:100%;min-height:300px;background:linear-gradient(180deg,#f8fefb,#eef9f1);border-radius:16px;border:1px solid #dce8de;overflow:hidden;}"
            ".orbit-sun{position:absolute;left:52px;top:50%;transform:translateY(-50%);width:118px;height:118px;border-radius:50%;background:radial-gradient(circle at 35% 35%,#fff8d6 0,#fde68a 46%,#f59e0b 100%);box-shadow:0 0 0 12px rgba(245,158,11,.08),0 18px 40px rgba(245,158,11,.18);}"
            ".orbit-path{position:absolute;left:160px;right:44px;top:38px;bottom:38px;border:2px dashed #9dd9c0;border-radius:50%;}"
            ".earth-dot{position:absolute;right:104px;top:50%;transform:translateY(-50%);width:94px;height:94px;border-radius:50%;background:radial-gradient(circle at 34% 34%,#a7f3d0 0,#34d399 58%,#0f766e 100%);box-shadow:0 18px 32px rgba(15,118,110,.18);}"
            ".earth-dot::after{content:'';position:absolute;inset:0;border-radius:50%;background:linear-gradient(90deg,rgba(255,255,255,.42),transparent 55%,rgba(0,0,0,.12));animation:spin 5s linear infinite;}"
            "@keyframes spin{from{transform:rotate(0deg);}to{transform:rotate(360deg);}}"
            "</style>"
            "<script>(function(){function setActive(group,key){if(!group)return;group.querySelectorAll('[data-switch]').forEach(function(btn){btn.classList.toggle('active',btn.getAttribute('data-switch')===key)});group.querySelectorAll('[data-panel]').forEach(function(panel){panel.style.display=panel.getAttribute('data-panel')===key?'':'none'});}document.addEventListener('click',function(e){var tab=e.target.closest&&e.target.closest('[data-switch]');if(tab){var group=tab.closest('[data-tab-group]');setActive(group,tab.getAttribute('data-switch'));return;}var toggle=e.target.closest&&e.target.closest('[data-toggle]');if(toggle){var target=toggle.getAttribute('data-toggle');var host=toggle.closest('[data-toggle-group]')||toggle.parentElement||document;var panel=host.querySelector('[data-target=\"'+target+'\"]');if(panel){panel.style.display=panel.style.display==='none'?'':'none';toggle.classList.toggle('active');}return;}});})();</script>"
            "<div class='zj-top'><div><h2>" + title_html + "</h2><p>" + subtitle_html + "</p></div><div class='zj-badge'>AI生成</div></div>"
            "<div class='zj-stage'>"
            + body +
            "</div>"
            "<div class='zj-footer'><div>" + footer_html + "</div><div>页面内可点击交互</div></div>"
            "</div>"
        )

    def _fallback_cylinder_courseware(self, prompt: str, subject: str, grade: str, page_count: int) -> dict:
        prompt = self._repair_text(prompt)
        title = "圆柱的体积（第一课时）"
        pages = [
            {
                "type": "title",
                "title": "封面",
                "content": self._courseware_shell_clean(
                    title,
                    f"{subject or '数学'} · {grade or '六年级'}",
                    """
<div style='position:absolute;inset:0;background:linear-gradient(135deg,#f4fbf7 0%,#ffffff 52%,#eaf7ef 100%);'>
  <div style='position:absolute;left:54px;top:52px;padding:8px 14px;border-radius:18px;background:rgba(0,84,61,.08);color:#00543d;font-size:13px;font-weight:700;'>课堂导入</div>
  <div style='position:absolute;left:54px;right:54px;top:76px;bottom:26px;display:grid;grid-template-columns:1.1fr .9fr;gap:26px;align-items:center;'>
    <div>
      <div class='zj-pill'>数学 · 形体与测量</div>
      <h1 style='margin:18px 0 0;font-size:42px;line-height:1.08;color:#12372d;'>圆柱的体积</h1>
      <p style='margin:18px 0 0;font-size:20px;line-height:1.7;color:#33544b;max-width:460px;'>围绕“底面积 × 高”展开探究，通过观察、切分、比较和例题，把抽象公式变成可理解、可操作的课堂体验。</p>
      <div style='margin-top:24px;display:flex;gap:12px;flex-wrap:wrap;'>
        <span class='zj-chip'>层次清楚</span>
        <span class='zj-chip'>页面可切换</span>
        <span class='zj-chip'>支持课堂互动</span>
      </div>
    </div>
    <div style='position:relative;height:100%;min-height:260px;'>
      <div style='position:absolute;left:48px;top:30px;width:240px;height:240px;border-radius:50%;background:radial-gradient(circle at 50% 40%,#ecfdf5 0,#d1fae5 45%,#86efac 100%);box-shadow:0 18px 40px rgba(0,168,112,.14);'></div>
      <div style='position:absolute;left:92px;top:62px;width:148px;height:182px;border-left:3px solid #00a870;border-right:3px solid #00a870;background:linear-gradient(90deg,rgba(0,168,112,.10),rgba(255,255,255,.58),rgba(0,168,112,.10));border-radius:26px;'></div>
      <div style='position:absolute;left:92px;top:36px;width:148px;height:52px;border-radius:50%;background:#d1fae5;border:3px solid #00a870;'></div>
      <div style='position:absolute;left:92px;top:212px;width:148px;height:52px;border-radius:50%;background:#a7f3d0;border:3px solid #00a870;'></div>
    </div>
  </div>
</div>
""",
                    "封面页",
                ),
                "notes": "封面",
            },
            {
                "type": "content",
                "title": "知识回顾",
                "content": self._courseware_shell_clean(
                    "知识回顾",
                    "先把旧知识拉回来，再进入新课探究",
                    """
<div class='zj-grid2' data-tab-group='rev' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:240px 1fr;gap:16px;'>
  <div style='display:grid;gap:12px;align-content:start;'>
    <button type='button' class='season-btn active' data-switch='rev1'>
      <span style='font-size:18px;'>长方体体积</span>
    </button>
    <button type='button' class='season-btn' data-switch='rev2'>
      <span style='font-size:18px;'>正方体体积</span>
    </button>
    <button type='button' class='season-btn' data-switch='rev3'>
      <span style='font-size:18px;'>迁移到新知</span>
    </button>
  </div>
  <div class='zj-card' style='padding:22px;display:flex;flex-direction:column;justify-content:center;'>
    <div class='rev-panel rev1' data-panel='rev1'>
      <div class='zj-pill'>旧知 1</div>
      <h3 style='margin:14px 0 10px;font-size:28px;color:#00543d;'>长方体体积公式</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;'>体积和底面积、高有关。先看“底面铺了多少”，再看“竖起来有多高”。</p>
    </div>
    <div class='rev-panel rev2' data-panel='rev2' style='display:none;'>
      <div class='zj-pill'>旧知 2</div>
      <h3 style='margin:14px 0 10px;font-size:28px;color:#00543d;'>正方体体积公式</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;'>棱长相等，体积计算更简单，但核心思想仍是“每层面积 × 层数”。</p>
    </div>
    <div class='rev-panel rev3' data-panel='rev3' style='display:none;'>
      <div class='zj-pill'>新课前置</div>
      <h3 style='margin:14px 0 10px;font-size:28px;color:#00543d;'>圆柱能否转化？</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;'>如果把圆柱沿着高切开，再拼成近似长方体，体积关系会更清楚。</p>
    </div>
  </div>
</div>
""",
                    "点击卡片切换旧知",
                ),
                "notes": "知识回顾",
            },
            {
                "type": "interactive",
                "title": "引入新知",
                "content": self._courseware_shell_clean(
                    "引入新知",
                    "先看形状和高度，再让学生猜一猜体积和什么有关",
                    """
<div style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;' class='zj-grid2'>
  <div style='position:relative;min-height:300px;background:linear-gradient(180deg,#f8fefb,#eef9f1);border-radius:16px;border:1px solid #dce8de;overflow:hidden;'>
    <div style='position:absolute;left:24px;top:24px;padding:8px 12px;border-radius:16px;background:#00543d;color:#fff;font-size:13px;font-weight:700;'>情境导入</div>
    <div style='position:absolute;left:86px;top:82px;width:160px;height:230px;border-left:4px solid #00a870;border-right:4px solid #00a870;background:linear-gradient(90deg,rgba(0,168,112,.14),rgba(255,255,255,.65),rgba(0,168,112,.14));border-radius:30px;'></div>
    <div style='position:absolute;left:86px;top:50px;width:160px;height:62px;border-radius:50%;background:#d1fae5;border:4px solid #00a870;'></div>
    <div style='position:absolute;left:86px;top:250px;width:160px;height:62px;border-radius:50%;background:#a7f3d0;border:4px solid #00a870;'></div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;flex-direction:column;justify-content:center;'>
    <div class='zj-pill'>课堂提问</div>
    <h3 style='margin:14px 0 12px;font-size:28px;color:#12372d;'>你觉得圆柱体积和什么有关？</h3>
    <div style='display:grid;gap:10px;margin-top:10px;'>
      <div class='zj-card' style='padding:14px 16px;'>A. 只和底面形状有关</div>
      <div class='zj-card' style='padding:14px 16px;'>B. 和底面积、高都有关系</div>
      <div class='zj-card' style='padding:14px 16px;'>C. 只和颜色有关</div>
    </div>
    <div style='margin-top:18px;padding:14px 16px;border-left:4px solid #00a870;background:#f7faf8;border-radius:10px;color:#33544b;'>课堂结论：体积计算要抓住“底面积 × 高”这条主线。</div>
  </div>
</div>
""",
                    "学生先猜想，再看图验证",
                ),
                "notes": "引入",
            },
            {
                "type": "content",
                "title": "公式探究",
                "content": self._courseware_shell_clean(
                    "公式探究",
                    "用切、拼、比的方式，把圆柱体积想清楚",
                    """
<div class='zj-grid2' data-tab-group='step' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:240px 1fr;gap:16px;'>
  <div style='display:grid;gap:10px;align-content:start;'>
    <button type='button' class='season-btn active' data-switch='step1'>
      <span style='font-size:18px;'>切一切</span>
    </button>
    <button type='button' class='season-btn' data-switch='step2'>
      <span style='font-size:18px;'>拼一拼</span>
    </button>
    <button type='button' class='season-btn' data-switch='step3'>
      <span style='font-size:18px;'>想一想</span>
    </button>
  </div>
  <div class='zj-card' style='padding:22px;position:relative;overflow:auto;'>
    <div class='step-panel s1' data-panel='step1'>
      <div class='zj-pill'>切分观察</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>把圆柱切成很多薄片</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:560px;'>圆柱越像被分成很多很薄的小层，每一层越接近一个圆形小面。层数越多，拼出的形状就越接近长方体。</p>
    </div>
    <div class='step-panel s2' data-panel='step2' style='display:none;'>
      <div class='zj-pill'>转化比较</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>拼成近似长方体</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:560px;'>切开后重新排列，底面形状变了，但每一层的面积总和没有变，高也没有变，所以体积也没有变。</p>
      <div style='margin-top:18px;font-size:34px;font-weight:800;color:#12372d;'>V = 底面积 × 高</div>
    </div>
    <div class='step-panel s3' data-panel='step3' style='display:none;'>
      <div class='zj-pill'>归纳结论</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>圆柱体积公式</h3>
      <div style='font-size:38px;font-weight:800;color:#12372d;'>V = S × h</div>
      <p style='margin:12px 0 0;font-size:18px;line-height:1.8;color:#33544b;'>S 表示底面积，h 表示高。知道这两个量，就能求圆柱的体积。</p>
    </div>
  </div>
</div>
""",
                    "切、拼、比，逐步导出公式",
                ),
                "notes": "公式探究",
            },
            {
                "type": "interactive",
                "title": "例题讲解",
                "content": self._courseware_shell_clean(
                    "例题讲解",
                    "把公式落到计算里，按步骤说清楚",
                    """
<div class='zj-grid2' data-tab-group='ex' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 320px;gap:16px;'>
  <div class='zj-card' style='padding:22px;'>
    <div class='zj-pill'>例题</div>
    <h3 style='margin:14px 0 12px;font-size:28px;color:#12372d;'>一个圆柱的底面积是 28.26 cm²，高是 10 cm，体积是多少？</h3>
    <div class='zj-grid3' style='margin-top:16px;'>
      <button type='button' class='season-btn active' data-switch='ex1'>
        <span style='font-size:18px;'>第 1 步</span>
      </button>
      <button type='button' class='season-btn' data-switch='ex2'>
        <span style='font-size:18px;'>第 2 步</span>
      </button>
      <button type='button' class='season-btn' data-switch='ex3'>
        <span style='font-size:18px;'>第 3 步</span>
      </button>
    </div>
    <div style='margin-top:18px;padding:18px;border-radius:14px;background:#f7faf8;border:1px solid #dce8de;'>
      <div class='ex-panel ex1' data-panel='ex1'>
        <div style='font-size:16px;color:#6b7f76;'>已知</div>
        <div style='margin-top:8px;font-size:20px;color:#12372d;font-weight:700;'>S = 28.26 cm²，h = 10 cm</div>
      </div>
      <div class='ex-panel ex2' data-panel='ex2' style='display:none;'>
        <div style='font-size:16px;color:#6b7f76;'>公式</div>
        <div style='margin-top:8px;font-size:28px;color:#12372d;font-weight:800;'>V = S × h</div>
        <div style='margin-top:8px;font-size:18px;color:#33544b;'>V = 28.26 × 10</div>
      </div>
      <div class='ex-panel ex3' data-panel='ex3' style='display:none;'>
        <div style='font-size:16px;color:#6b7f76;'>结果</div>
        <div style='margin-top:8px;font-size:32px;color:#00543d;font-weight:800;'>V = 282.6 cm³</div>
        <div style='margin-top:8px;font-size:18px;color:#33544b;'>答：这个圆柱的体积是 282.6 立方厘米。</div>
      </div>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;flex-direction:column;gap:12px;justify-content:center;'>
    <div class='zj-pill'>解题提醒</div>
    <div style='font-size:18px;line-height:1.8;color:#33544b;'>圆柱体积公式中的 <strong>S</strong> 是底面积，不是底面周长。单位也要对应写成立方单位。</div>
    <div style='padding:14px 16px;border-radius:12px;background:#ecfdf5;color:#00543d;'>写答语时要带上单位，例如 cm³、m³。</div>
  </div>
</div>
""",
                    "按步骤理解计算过程",
                ),
                "notes": "例题",
            },
            {
                "type": "exercise",
                "title": "巩固练习",
                "content": self._courseware_shell_clean(
                    "巩固练习",
                    "点击选项，立即查看判断结果",
                    """
<div class='zj-grid2' data-tab-group='q1' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 320px;gap:16px;'>
  <div class='zj-card' style='padding:22px;'>
    <div class='zj-pill'>选择题</div>
    <h3 style='margin:14px 0 12px;font-size:28px;color:#12372d;'>圆柱体积公式正确的是哪一个？</h3>
    <div style='display:grid;gap:10px;margin-top:16px;'>
      <button type='button' class='season-btn active' data-switch='qa' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>A. V = 底面周长 × 高</span>
      </button>
      <button type='button' class='season-btn' data-switch='qb' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>B. V = 底面积 × 高</span>
      </button>
      <button type='button' class='season-btn' data-switch='qc' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>C. V = 半径 × 高</span>
      </button>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;align-items:center;justify-content:center;text-align:left;'>
    <div class='q-panel qa' data-panel='qa'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#b45309;'>A 不是正确答案。圆柱体积不是把周长直接相乘。</div>
    </div>
    <div class='q-panel qb' data-panel='qb' style='display:none;'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#00543d;'>回答正确。圆柱体积就是“底面积 × 高”。</div>
    </div>
    <div class='q-panel qc' data-panel='qc' style='display:none;'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#b45309;'>C 不是正确答案。半径只是求底面积的一个中间量。</div>
    </div>
  </div>
</div>
""",
                    "选择答案后直接反馈",
                ),
                "notes": "练习",
            },
            {
                "type": "summary",
                "title": "总结",
                "content": self._courseware_shell_clean(
                    "总结与作业",
                    "把公式、方法和易错点一次收好",
                    """
<div class='zj-grid2' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 340px;gap:16px;'>
  <div class='zj-card' style='padding:22px;'>
    <div class='zj-pill'>本课总结</div>
    <div style='display:grid;gap:12px;margin-top:16px;'>
      <div class='zj-card' style='padding:14px 16px;'>1. 圆柱体积公式：V = S × h</div>
      <div class='zj-card' style='padding:14px 16px;'>2. 核心方法：切、拼、转化成近似长方体</div>
      <div class='zj-card' style='padding:14px 16px;'>3. 易错提醒：S 是底面积，不是底面周长</div>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;flex-direction:column;justify-content:center;gap:12px;' data-toggle-group='homework-block'>
    <div class='zj-pill'>课后任务</div>
    <div style='font-size:18px;line-height:1.8;color:#33544b;'>1. 完成课本练习。<br>2. 找一个生活中的圆柱体，量一量底面和高，试着算体积。</div>
    <button type='button' class='zj-btn alt' data-toggle='hw' style='display:inline-flex;align-items:center;justify-content:center;'>点击展开提醒</button>
    <div class='hw-panel' data-target='hw' style='padding:14px 16px;border-radius:12px;background:#f7faf8;border:1px solid #dce8de;display:none;'>记得带单位，写成立方厘米、立方分米或立方米。</div>
  </div>
</div>
""",
                    "总结方法并布置作业",
                ),
                "notes": "总结",
            },
        ]
        total = max(5, min(page_count or 7, len(pages)))
        return {"title": title, "summary": "围绕底面积与高探究圆柱体积", "tags": ["圆柱", "体积", "互动课件"], "pages": pages[:total]}

    def _fallback_orbit_courseware(self, prompt: str, subject: str, grade: str, page_count: int) -> dict:
        prompt = self._repair_text(prompt)
        title = "地球公转与四季变化"
        pages = [
            {
                "type": "title",
                "title": "封面",
                "content": self._courseware_shell_clean(
                    title,
                    f"{subject or '科学'} · {grade or '六年级'}",
                    """
<div style='position:absolute;inset:0;background:linear-gradient(135deg,#f4fbf7 0%,#ffffff 52%,#eaf7ef 100%);'>
  <div style='position:absolute;left:54px;top:52px;padding:8px 14px;border-radius:18px;background:rgba(0,84,61,.08);color:#00543d;font-size:13px;font-weight:700;'>情境导入</div>
  <div style='position:absolute;left:54px;right:54px;top:76px;bottom:26px;display:grid;grid-template-columns:1.1fr .9fr;gap:26px;align-items:center;'>
    <div>
      <div class='zj-pill'>科学 · 地球与宇宙</div>
      <h1 style='margin:18px 0 0;font-size:42px;line-height:1.08;color:#12372d;'>地球公转与四季变化</h1>
      <p style='margin:18px 0 0;font-size:20px;line-height:1.7;color:#33544b;max-width:460px;'>通过轨道、倾角和阳光照射方向的变化，把春夏秋冬的形成过程讲清楚、看明白、能点击。</p>
      <div style='margin-top:24px;display:flex;gap:12px;flex-wrap:wrap;'>
        <span class='zj-chip'>轨道示意</span>
        <span class='zj-chip'>四季按钮</span>
        <span class='zj-chip'>课堂可演示</span>
      </div>
    </div>
    <div style='position:relative;height:100%;min-height:260px;'>
      <div class='orbit-wrap'>
        <div class='orbit-sun'></div>
        <div class='orbit-path'></div>
        <div class='earth-dot'></div>
      </div>
    </div>
  </div>
</div>
""",
                    "封面页",
                ),
                "notes": "封面",
            },
            {
                "type": "content",
                "title": "知识回顾",
                "content": self._courseware_shell_clean(
                    "知识回顾",
                    "先把轨道、地轴倾斜和太阳光照这三个要点记住",
                    """
<div style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;' class='zj-grid3'>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>要点 1</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>地球在公转</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>地球绕太阳转一圈，需要大约一年。</p>
  </div>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>要点 2</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>地轴是倾斜的</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>地轴倾斜让同一地区在不同时间受到的阳光不同。</p>
  </div>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>要点 3</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>太阳光照变化</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>阳光照射角度和昼夜长短，会随着公转位置变化。</p>
  </div>
</div>
""",
                    "三个关键概念先对齐",
                ),
                "notes": "知识回顾",
            },
            {
                "type": "interactive",
                "title": "四季探究",
                "content": self._courseware_shell_clean(
                    "四季探究",
                    "点击春夏秋冬，观察光照和气候变化",
                    """
<div class='zj-grid2' data-tab-group='season' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:230px 1fr;gap:16px;overflow:auto;'>
  <div style='display:grid;gap:10px;align-content:start;'>
    <button type='button' class='season-btn active' data-switch='spring'>春天</button>
    <button type='button' class='season-btn' data-switch='summer'>夏天</button>
    <button type='button' class='season-btn' data-switch='autumn'>秋天</button>
    <button type='button' class='season-btn' data-switch='winter'>冬天</button>
  </div>
  <div class='zj-card' style='padding:22px;position:relative;overflow:auto;'>
    <div class='season-panel' data-panel='spring'>
      <div class='zj-pill'>春季</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>阳光开始变强，气温慢慢回升</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>春季时太阳直射位置逐渐北移，北半球白天变长，天气回暖，植物也开始生长。</p>
    </div>
    <div class='season-panel' data-panel='summer' style='display:none;'>
      <div class='zj-pill'>夏季</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>阳光更强，白天更长</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>夏季时北半球受到的太阳光更直接，地面获得的热量更多，所以气温更高、白昼更长。</p>
    </div>
    <div class='season-panel' data-panel='autumn' style='display:none;'>
      <div class='zj-pill'>秋季</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>阳光减弱，天气转凉</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>秋季太阳直射位置继续变化，白天变短，气温下降，作物开始成熟和收获。</p>
    </div>
    <div class='season-panel' data-panel='winter' style='display:none;'>
      <div class='zj-pill'>冬季</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>阳光较弱，白天更短</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>冬季时太阳光照更斜，地面接收热量少，所以天气寒冷，白昼也更短。</p>
    </div>
  </div>
</div>
<style>
.season-btn.active{border-color:#00a870;background:#ecfdf5;color:#00543d;box-shadow:0 10px 18px rgba(0,168,112,.10);}
</style>
""",
                    "四季按钮可直接切换",
                ),
                "notes": "四季探究",
            },
            {
                "type": "content",
                "title": "现象解释",
                "content": self._courseware_shell_clean(
                    "现象解释",
                    "同样是太阳，为什么不同季节感觉不一样？",
                    """
<div style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 1fr;gap:16px;'>
  <div class='zj-card' style='padding:20px;'>
    <div class='zj-pill'>原因 1</div>
    <h3 style='margin:14px 0 10px;font-size:28px;color:#00543d;'>阳光直射角度不同</h3>
    <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;'>角度越直，单位面积接收到的热量越多；角度越斜，热量越分散。</p>
  </div>
  <div class='zj-card' style='padding:20px;'>
    <div class='zj-pill'>原因 2</div>
    <h3 style='margin:14px 0 10px;font-size:28px;color:#00543d;'>白昼长短不同</h3>
    <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;'>白天越长，太阳照射时间越久，地面吸收热量也更多。</p>
  </div>
</div>
""",
                    "从光照与时间两个角度解释",
                ),
                "notes": "现象解释",
            },
            {
                "type": "summary",
                "title": "总结",
                "content": self._courseware_shell_clean(
                    "总结与作业",
                    "把公转、地轴倾斜和四季变化连起来理解",
                    """
<div class='zj-grid2' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 340px;gap:16px;'>
  <div class='zj-card' style='padding:22px;'>
    <div class='zj-pill'>本课总结</div>
    <div style='display:grid;gap:12px;margin-top:16px;'>
      <div class='zj-card' style='padding:14px 16px;'>1. 地球围绕太阳公转，形成一年四季的周期变化。</div>
      <div class='zj-card' style='padding:14px 16px;'>2. 地轴倾斜，让不同季节接受的阳光不同。</div>
      <div class='zj-card' style='padding:14px 16px;'>3. 阳光直射角度和白昼长短，决定了冷热变化。</div>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;flex-direction:column;justify-content:center;gap:12px;' data-toggle-group='season-homework'>
    <div class='zj-pill'>课后任务</div>
    <div style='font-size:18px;line-height:1.8;color:#33544b;'>1. 画一张地球绕太阳公转示意图。<br>2. 说一说春夏秋冬各自最明显的特点。</div>
    <button type='button' class='zj-btn alt' data-toggle='season-hw' style='display:inline-flex;align-items:center;justify-content:center;'>点击展开提示</button>
    <div class='season-hw-panel' data-target='season-hw' style='padding:14px 16px;border-radius:12px;background:#f7faf8;border:1px solid #dce8de;display:none;'>答题时可以先写“原因”，再写“现象”，这样更完整。</div>
  </div>
</div>
""",
                    "把四季原因说完整",
                ),
                "notes": "总结",
            },
        ]
        total = max(5, min(page_count or 6, len(pages)))
        return {"title": title, "summary": "围绕地球公转与太阳光照变化解释四季形成", "tags": ["地球公转", "四季", "科学探究"], "pages": pages[:total]}

    def _fallback_general_courseware(self, prompt: str, subject: str, grade: str, page_count: int) -> dict:
        prompt = self._repair_text(prompt)
        title = prompt[:24] or "互动课件"
        pages = [
            {
                "type": "title",
                "title": "封面",
                "content": self._courseware_shell_clean(
                    title,
                    f"{subject or '综合'} · {grade or '课堂教学'}",
                    """
<div style='position:absolute;inset:0;background:linear-gradient(135deg,#f4fbf7 0%,#ffffff 52%,#eaf7ef 100%);'>
  <div style='position:absolute;left:54px;top:52px;padding:8px 14px;border-radius:18px;background:rgba(0,84,61,.08);color:#00543d;font-size:13px;font-weight:700;'>课堂导入</div>
  <div style='position:absolute;left:54px;right:54px;top:76px;bottom:26px;display:grid;grid-template-columns:1.1fr .9fr;gap:26px;align-items:center;'>
    <div>
      <div class='zj-pill'>知识生成 · 互动呈现</div>
      <h1 style='margin:18px 0 0;font-size:42px;line-height:1.08;color:#12372d;'>""" + html_lib.escape(title) + """</h1>
      <p style='margin:18px 0 0;font-size:20px;line-height:1.7;color:#33544b;max-width:460px;'>用清爽、分层、可点击的页面组织课堂内容，适合投屏展示和逐步讲解。</p>
      <div style='margin-top:24px;display:flex;gap:12px;flex-wrap:wrap;'>
        <span class='zj-chip'>层次清楚</span>
        <span class='zj-chip'>页面可切换</span>
        <span class='zj-chip'>支持课堂互动</span>
      </div>
    </div>
    <div style='position:relative;height:100%;min-height:260px;'>
      <div class='orbit-wrap'>
        <div class='orbit-sun'></div>
        <div class='orbit-path'></div>
        <div class='earth-dot'></div>
      </div>
    </div>
  </div>
</div>
""",
                    "封面页",
                ),
                "notes": "封面",
            },
            {
                "type": "content",
                "title": "核心概念",
                "content": self._courseware_shell_clean(
                    "核心概念",
                    "先把问题拆开，再逐步组织内容",
                    """
<div style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;' class='zj-grid3'>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>第 1 点</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>要讲什么</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>把主题拆成 2 到 3 个核心问题，再分别展开。</p>
  </div>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>第 2 点</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>怎么讲</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>先观察，再归纳，最后用例子验证。</p>
  </div>
  <div class='zj-card' style='padding:18px;'>
    <div class='zj-pill'>第 3 点</div>
    <h3 style='margin:14px 0 8px;font-size:22px;color:#00543d;'>怎么练</h3>
    <p style='margin:0;font-size:16px;line-height:1.7;color:#33544b;'>用点击反馈、小练习和总结页收尾。</p>
  </div>
</div>
""",
                    "搭好课堂结构",
                ),
                "notes": "核心概念",
            },
            {
                "type": "interactive",
                "title": "互动探究",
                "content": self._courseware_shell_clean(
                    "互动探究",
                    "点击左侧选项，右侧显示不同内容",
                    """
<div class='zj-grid2' data-tab-group='g' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:230px 1fr;gap:16px;overflow:auto;'>
  <div style='display:grid;gap:10px;align-content:start;'>
    <button type='button' class='season-btn active' data-switch='g1'>观察</button>
    <button type='button' class='season-btn' data-switch='g2'>分析</button>
    <button type='button' class='season-btn' data-switch='g3'>总结</button>
  </div>
  <div class='zj-card' style='padding:22px;position:relative;overflow:auto;'>
    <div class='g-panel g1' data-panel='g1'>
      <div class='zj-pill'>观察</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>先看现象，再找规律</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>围绕图片、数据或情境，先让学生说出“看见了什么”，再引导他们说“为什么会这样”。</p>
    </div>
    <div class='g-panel g2' data-panel='g2' style='display:none;'>
      <div class='zj-pill'>分析</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>把线索整理成逻辑</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>把原因、结果和条件分开写清楚，再用一两句话把关系串起来。</p>
    </div>
    <div class='g-panel g3' data-panel='g3' style='display:none;'>
      <div class='zj-pill'>总结</div>
      <h3 style='margin:14px 0 10px;font-size:30px;color:#00543d;'>把关键结论收拢</h3>
      <p style='margin:0;font-size:18px;line-height:1.8;color:#33544b;max-width:600px;'>最后把今天最重要的一句话写成结论，方便学生复述和记忆。</p>
    </div>
  </div>
</div>
""",
                    "交互区可直接切换",
                ),
                "notes": "互动探究",
            },
            {
                "type": "exercise",
                "title": "课堂练习",
                "content": self._courseware_shell_clean(
                    "课堂练习",
                    "选择一个答案，马上看反馈",
                    """
<div class='zj-grid2' data-tab-group='h' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 320px;gap:16px;overflow:auto;'>
  <div class='zj-card' style='padding:22px;overflow:auto;'>
    <div class='zj-pill'>练习题</div>
    <h3 style='margin:14px 0 12px;font-size:28px;color:#12372d;'>下面哪一种说法最符合今天的主题？</h3>
    <div style='display:grid;gap:10px;margin-top:16px;'>
      <button type='button' class='season-btn active' data-switch='h1' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>A. 只要记住一个结论就够了</span>
      </button>
      <button type='button' class='season-btn' data-switch='h2' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>B. 要把观察、分析和总结连起来</span>
      </button>
      <button type='button' class='season-btn' data-switch='h3' style='justify-content:flex-start;padding:0 16px;'>
        <span style='font-size:16px;'>C. 课堂上不需要互动</span>
      </button>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;align-items:center;justify-content:center;text-align:left;'>
    <div class='h-panel h1' data-panel='h1'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#b45309;'>A 不完整。课堂结构不能只靠一个结论支撑。</div>
    </div>
    <div class='h-panel h2' data-panel='h2' style='display:none;'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#00543d;'>回答正确。课堂内容应该有完整的观察、分析和总结链条。</div>
    </div>
    <div class='h-panel h3' data-panel='h3' style='display:none;'>
      <div class='zj-pill'>反馈</div>
      <div style='margin-top:12px;font-size:18px;line-height:1.8;color:#b45309;'>C 不符合互动课件的设计原则。</div>
    </div>
  </div>
</div>
""",
                    "选择后看反馈",
                ),
                "notes": "课堂练习",
            },
            {
                "type": "summary",
                "title": "总结",
                "content": self._courseware_shell_clean(
                    "总结与作业",
                    "把今天的重点提炼成一页",
                    """
<div class='zj-grid2' style='position:absolute;left:22px;right:22px;top:22px;bottom:22px;display:grid;grid-template-columns:1fr 340px;gap:16px;overflow:auto;'>
  <div class='zj-card' style='padding:22px;overflow:auto;'>
    <div class='zj-pill'>本课总结</div>
    <div style='display:grid;gap:12px;margin-top:16px;'>
      <div class='zj-card' style='padding:14px 16px;'>1. 先观察，再分析，再总结。</div>
      <div class='zj-card' style='padding:14px 16px;'>2. 把复杂内容拆成若干清楚的部分。</div>
      <div class='zj-card' style='padding:14px 16px;'>3. 用点击互动提高课堂参与感。</div>
    </div>
  </div>
  <div class='zj-card' style='padding:20px;display:flex;flex-direction:column;justify-content:center;gap:12px;' data-toggle-group='general-homework'>
    <div class='zj-pill'>课后任务</div>
    <div style='font-size:18px;line-height:1.8;color:#33544b;'>1. 把本课内容整理成 3 条要点。<br>2. 试着为一个新的知识点设计 1 个互动问题。</div>
    <button type='button' class='zj-btn alt' data-toggle='g-hw' style='display:inline-flex;align-items:center;justify-content:center;'>点击展开提示</button>
    <div class='g-hw-panel' data-target='g-hw' style='padding:14px 16px;border-radius:12px;background:#f7faf8;border:1px solid #dce8de;display:none;'>提示：结论要短，任务要具体，方便学生完成。</div>
  </div>
</div>
""",
                    "整理成可复述的结论",
                ),
                "notes": "总结",
            },
        ]
        total = max(5, min(page_count or 5, len(pages)))
        return {"title": title, "summary": "把主题拆分成观察、分析、总结的互动课件", "tags": ["互动课件", "可点击", "课堂讲解"], "pages": pages[:total]}

    async def generate_courseware(self, prompt: str, subject: str = "", grade: str = "", page_count: int = 8, aspect_ratio: str = "16:9") -> dict:
        prompt = self._repair_text(prompt)
        topic = self._courseware_topic(prompt)
        if topic == "cylinder":
            return self._fallback_cylinder_courseware(prompt, subject or "数学", grade or "六年级", page_count)
        if topic == "orbit":
            return self._fallback_orbit_courseware(prompt, subject or "科学", grade or "六年级", page_count)

        try:
            result = await self._chat_json([
                {"role": "system", "content": "请生成多页互动课件 JSON，包含 title、summary、tags、pages。每页 content 必须是可直接渲染的 <div> HTML 片段，页面结构清爽，适合教室投屏。"},
                {"role": "user", "content": f"学科：{subject or '未指定'}\n年级：{grade or '未指定'}\n页数要求：{page_count}\n\n教师需求：{prompt}"},
            ], temperature=0.45, max_tokens=12000)
            normalized = self._normalize_courseware_result(result, prompt, subject, grade, page_count, aspect_ratio)
            if normalized:
                return normalized
        except Exception:
            pass
        return self._fallback_general_courseware(prompt, subject, grade, page_count)