// ==UserScript==
// @name         AI答题
// @namespace    https://github.com/QfangY/ai-answer
// @homepageURL  https://github.com/QfangY/ai-answer
// @icon         https://raw.githubusercontent.com/QfangY/ai-answer/main/icon.svg
// @version      2.1.2
// @description  学习通智能答题助手，支持多AI接口、自动识别题目和答题、可配置控制面板。
// @author       QfangY
// @license      MIT
// @match        https://mooc1.chaoxing.com/mooc-ans/mooc2/work/view*
// @match        https://mooc1.chaoxing.com/mooc-ans/mooc2/work/dowork*
// @match        https://mooc1.chaoxing.com/mooc-ans/mooc2/exam/*
// @match        https://mooc1.chaoxing.com/mooc-ans/mooc-ans-work/*
// @grant        GM_setClipboard
// @grant        GM_addStyle
// @grant        GM_xmlhttpRequest
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      api.deepseek.com
// @connect      api.openai.com
// @connect      api.xiaomimimo.com
// @connect      dashscope.aliyuncs.com
// @connect      open.bigmodel.cn
// @connect      api-inference.modelscope.cn
// @connect      localhost
// @connect      127.0.0.1
// @run-at       document-end
// ==/UserScript==

(function() {
    'use strict';

    // ============================================================
    //  常量与默认配置
    // ============================================================
    const STORAGE_PREFIX = 'chaoxing-ai-v2';
    const STORAGE_KEYS = {
        aiConfig:    `${STORAGE_PREFIX}.ai-config`,
        ballPos:     `${STORAGE_PREFIX}.ball-position`,
        settings:    `${STORAGE_PREFIX}.ui-settings`,
        wizardSeen:  `${STORAGE_PREFIX}.wizard-seen`
    };

    const AI_PROVIDERS = [
        { id: 'custom',     name: '自定义',         url: '', model: '', desc: '手动填写API地址、模型和密钥' },
        { id: 'deepseek',   name: 'DeepSeek',       url: 'https://api.deepseek.com/v1/chat/completions', model: 'deepseek-v4-flash', desc: 'V4-Flash快速模型，国内首选' },
        { id: 'deepseek-p', name: 'DeepSeek(Pro)',  url: 'https://api.deepseek.com/v1/chat/completions', model: 'deepseek-v4-pro', desc: 'V4-Pro旗舰模型' },
        { id: 'mimo',       name: 'MiMo',           url: 'https://api.xiaomimimo.com/v1/chat/completions', model: 'mimo-v2.5-pro', desc: '小米MiMo，按量付费' },
        { id: 'mimo-flash', name: 'MiMo-Flash',     url: 'https://api.xiaomimimo.com/v1/chat/completions', model: 'mimo-v2-flash', desc: '小米MiMo-Flash，极速推理' },
        { id: 'qwen',       name: '通义千问',        url: 'https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions', model: 'qwen-plus', desc: '阿里云百炼，千问Plus' },
        { id: 'qwen-turbo', name: '千问Turbo',      url: 'https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions', model: 'qwen-turbo', desc: '千问Turbo，速度快价格低' },
        { id: 'zhipu',      name: '智谱AI',         url: 'https://open.bigmodel.cn/api/paas/v4/chat/completions', model: 'glm-4-flash', desc: 'GLM-4-Flash，免费模型' },
        { id: 'zhipu-5',    name: '智谱GLM-5',      url: 'https://open.bigmodel.cn/api/paas/v4/chat/completions', model: 'glm-5-turbo', desc: 'GLM-5-Turbo，旗舰模型' },
        { id: 'openai',     name: 'OpenAI',         url: 'https://api.openai.com/v1/chat/completions', model: 'gpt-4o-mini', desc: 'GPT-4o-mini，需要海外Key' },
        { id: 'ollama',     name: 'Ollama(本地)',    url: 'http://localhost:11434/v1/chat/completions', model: 'deepseek-r1:8b', desc: '本地部署，无需API Key' }
    ];

    const DEFAULT_AI_CONFIG = {
        provider: 'deepseek',
        apiUrl: 'https://api.deepseek.com/v1/chat/completions',
        model: 'deepseek-v4-flash',
        apiKey: '',
        temperature: 0.1
    };

    const DEFAULT_SETTINGS = {
        ballSize: 64,
        floatDuration: 4.8,
        panelWidth: 380,
        panelOpacity: 97,
        rememberPosition: true,
        reducedMotion: false,
        autoOpenPage: 'basic',
        autoAnswerDelay: 1500,
        autoNextQuestion: true
    };

    const DEFAULT_MARGIN = 20;

    // ============================================================
    //  工具函数
    // ============================================================
    const clamp = (v, min, max) => Math.min(Math.max(v, min), max);
    const safeParse = (t) => { try { return JSON.parse(t); } catch { return null; } };

    const loadJSON = (key, fallback) => {
        const raw = GM_getValue(key, null);
        if (raw === null) return { ...fallback };
        const parsed = typeof raw === 'string' ? safeParse(raw) : raw;
        return parsed ? { ...fallback, ...parsed } : { ...fallback };
    };
    const saveJSON = (key, obj) => GM_setValue(key, JSON.stringify(obj));

    // ============================================================
    //  状态管理
    // ============================================================
    let aiConfig = loadJSON(STORAGE_KEYS.aiConfig, DEFAULT_AI_CONFIG);
    let uiSettings = loadJSON(STORAGE_KEYS.settings, DEFAULT_SETTINGS);
    let autoAnswerRunning = false;
    let autoAnswerTimer = null;

    const saveAiConfig = () => saveJSON(STORAGE_KEYS.aiConfig, aiConfig);
    const saveUiSettings = () => saveJSON(STORAGE_KEYS.settings, uiSettings);

    // ============================================================
    //  AI 接口请求
    // ============================================================
    function callAiApi(prompt) {
        return new Promise((resolve, reject) => {
            if (!aiConfig.apiUrl) return reject(new Error('请先配置AI接口地址'));
            if (!aiConfig.apiKey && !aiConfig.apiUrl.includes('localhost') && !aiConfig.apiUrl.includes('127.0.0.1')) {
                return reject(new Error('请先配置API Key'));
            }

            const headers = { 'Content-Type': 'application/json' };
            if (aiConfig.apiKey) {
                headers['Authorization'] = `Bearer ${aiConfig.apiKey}`;
            }

            const body = JSON.stringify({
                model: aiConfig.model,
                messages: [
                    { role: 'system', content: '你是一个精准的答题助手。用户会给你题目和选项，你需要直接给出答案。只返回JSON数组，不要包含任何其他文字、markdown标记或代码块。格式：[{"questionId":"ID","answer":"答案内容","analysis":"简短解析"}]。选择题答案用选项字母（如A、B、AB），填空题直接给答案文本，判断题用"对"或"错"。' },
                    { role: 'user', content: prompt }
                ],
                temperature: aiConfig.temperature,
                stream: false
            });

            const bodySize = new Blob([body]).size;
            log(`🤖 正在请求AI (${aiConfig.model})...`, '#74b9ff');
            log(`📡 请求地址: ${aiConfig.apiUrl}`, '#636e72');
            log(`📦 请求体大小: ${(bodySize / 1024).toFixed(1)} KB`, '#636e72');

            const startTime = Date.now();

            GM_xmlhttpRequest({
                method: 'POST',
                url: aiConfig.apiUrl,
                headers,
                data: body,
                timeout: 120000, // 增加到120秒
                onload(resp) {
                    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
                    log(`📥 收到响应，耗时 ${elapsed}s，状态码: ${resp.status}`, '#636e72');

                    if (resp.status >= 200 && resp.status < 300) {
                        try {
                            const data = JSON.parse(resp.responseText);
                            const content = data.choices?.[0]?.message?.content || '';
                            const usage = data.usage;
                            if (usage) {
                                log(`📊 Token用量: 输入${usage.prompt_tokens} + 输出${usage.completion_tokens} = ${usage.total_tokens}`, '#636e72');
                            }
                            log(`✅ AI响应成功，响应长度: ${content.length} 字符`, '#55efc4');
                            resolve(content);
                        } catch (e) {
                            log(`❌ JSON解析失败: ${resp.responseText.substring(0, 200)}`, '#ff7675');
                            reject(new Error('AI返回格式解析失败'));
                        }
                    } else {
                        let errMsg = `AI请求失败 (${resp.status})`;
                        try {
                            const errData = JSON.parse(resp.responseText);
                            errMsg = errData.error?.message || errData.message || errMsg;
                            log(`❌ 错误详情: ${JSON.stringify(errData).substring(0, 300)}`, '#ff7675');
                        } catch {
                            log(`❌ 响应内容: ${resp.responseText.substring(0, 300)}`, '#ff7675');
                        }
                        reject(new Error(errMsg));
                    }
                },
                onerror(err) {
                    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
                    log(`❌ 网络请求失败，耗时 ${elapsed}s`, '#ff7675');
                    log(`❌ 错误信息: ${err.error || '未知错误'}`, '#ff7675');
                    reject(new Error('网络请求失败: ' + (err.error || '未知错误')));
                },
                ontimeout() {
                    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
                    log(`⏰ 请求超时，耗时 ${elapsed}s`, '#ff7675');
                    reject(new Error('AI请求超时(120s)，可能是网络问题或题目过多'));
                }
            });
        });
    }

    // ============================================================
    //  题目识别
    // ============================================================
    let questionCache = null;
    let lastDetectTime = 0;

    function detectQuestions(forceRefresh = false) {
        const now = Date.now();
        if (!forceRefresh && questionCache && (now - lastDetectTime) < 1000) {
            return questionCache;
        }

        const items = document.querySelectorAll('.questionLi');
        if (!items.length) {
            questionCache = [];
            return questionCache;
        }

        questionCache = Array.from(items).map((q, i) => {
            const id = q.getAttribute('data') || q.id?.replace('question', '') || String(i + 1);
            const title = q.querySelector('h3')?.innerText?.replace(/\s+/g, ' ').trim() || '';
            const type = q.getAttribute('typename') || '';

            let answered = false;
            
            // 检测选择题：查找选中的选项
            const selectedOptions = q.querySelectorAll('.answerBg[style], .answerBg.on, .answerBg.selected, .answerBg.click, [class*="selected"]');
            for (const opt of selectedOptions) {
                const style = opt.getAttribute('style') || '';
                if (style.includes('background') || style.includes('color') || 
                    opt.classList.contains('on') || opt.classList.contains('selected') || 
                    opt.classList.contains('click')) {
                    answered = true;
                    break;
                }
            }
            
            // 检测填空题/简答题：输入框有内容
            if (!answered) {
                const inputs = q.querySelectorAll('input[type="text"], input:not([type]), textarea');
                for (const input of inputs) {
                    if (input.value && input.value.trim().length > 0) {
                        answered = true;
                        break;
                    }
                }
            }
            
            // 检测编辑器：有内容
            if (!answered) {
                const editors = q.querySelectorAll('.edui-body-container, [contenteditable="true"]');
                for (const editor of editors) {
                    const text = editor.innerText?.trim();
                    if (text && text.length > 0 && text !== '请在此处输入答案' && text !== '请输入答案') {
                        answered = true;
                        break;
                    }
                }
            }
            
            // 检测iframe编辑器
            if (!answered) {
                const iframes = q.querySelectorAll('iframe');
                for (const iframe of iframes) {
                    try {
                        const body = iframe.contentDocument?.body;
                        if (body && body.innerText?.trim()?.length > 0) {
                            answered = true;
                            break;
                        }
                    } catch (e) {}
                }
            }

            const opts = Array.from(q.querySelectorAll('.answerBg, .answer_item, .options li')).map(o => o.innerText.trim()).filter(Boolean);
            return { id, title, type, options: opts, answered, element: q };
        });

        lastDetectTime = now;
        return questionCache;
    }

    function invalidateQuestionCache() {
        questionCache = null;
    }

    // ============================================================
    //  题目网格更新（全局）
    // ============================================================
    let startFromIndex = -1;
    let lastGridUpdate = 0;
    let gridUpdateTimer = null;

    function updateQuestionGrid(force = false) {
        const now = Date.now();
        if (!force && (now - lastGridUpdate) < 2000) {
            return;
        }

        const grid = document.getElementById('yan-question-grid');
        if (!grid) return;

        const questions = detectQuestions(force);
        if (!questions.length) {
            grid.innerHTML = '<div style="grid-column:1/-1;text-align:center;color:#718197;font-size:12px;padding:20px;">未检测到题目</div>';
            lastGridUpdate = now;
            return;
        }

        const answeredCount = questions.filter(q => q.answered).length;
        const fragment = document.createDocumentFragment();
        
        questions.forEach((q, i) => {
            const cell = document.createElement('div');
            cell.className = `yan-question-cell ${q.answered ? 'answered' : 'unanswered'}`;
            cell.dataset.index = i;
            cell.title = `题目 ${i+1} (ID: ${q.id}) - ${q.answered ? '已答' : '未答'}`;
            cell.textContent = i + 1;
            fragment.appendChild(cell);
        });

        grid.innerHTML = '';
        grid.appendChild(fragment);

        // 添加统计信息
        const stats = document.createElement('div');
        stats.style.cssText = 'grid-column:1/-1;text-align:center;font-size:11px;color:#718197;padding:4px 0;';
        stats.textContent = `共 ${questions.length} 题，已答 ${answeredCount} 题，未答 ${questions.length - answeredCount} 题`;
        grid.appendChild(stats);

        // 绑定点击事件
        grid.querySelectorAll('.yan-question-cell').forEach(cell => {
            cell.addEventListener('click', () => {
                const index = parseInt(cell.dataset.index);
                startFromIndex = index;
                if (typeof startAutoAnswerFromIndex === 'function') {
                    startAutoAnswerFromIndex(index);
                }
            });
        });

        lastGridUpdate = now;
    }

    async function startAutoAnswerFromIndex(startIndex) {
        if (autoAnswerRunning) {
            stopAutoAnswerLoop();
            await new Promise(r => setTimeout(r, 500));
        }

        autoAnswerRunning = true;
        updateAutoAnswerUI();
        log(`🚀 从第 ${startIndex + 1} 题开始自动答题`, '#00b894');

        const questions = detectQuestions(true);
        const unansweredFromStart = questions.slice(startIndex).filter(q => !q.answered);

        if (!unansweredFromStart.length) {
            log('📋 从该题开始没有未答题目', '#dfe6e9');
            stopAutoAnswerLoop();
            return;
        }

        log(`📊 从第 ${startIndex + 1} 题开始，有 ${unansweredFromStart.length} 道未答题`, '#74b9ff');

        let totalFilled = 0;
        let consecutiveErrors = 0;

        for (let i = 0; i < unansweredFromStart.length; i++) {
            if (!autoAnswerRunning) {
                log('⏹️ 自动答题已停止', '#fdcb6e');
                break;
            }

            const q = unansweredFromStart[i];
            const originalIndex = questions.indexOf(q);
            log(`📦 处理第 ${originalIndex + 1} 题 (ID: ${q.id})`, '#74b9ff');

            let prompt;
            try {
                prompt = buildPrompt([q]);
                log(`📝 Prompt生成成功，长度: ${prompt.length}`, '#636e72');
            } catch (e) {
                log(`❌ Prompt生成失败: ${e.message}`, '#ff7675');
                continue;
            }

            let response = null;
            let success = false;

            for (let retry = 0; retry < MAX_RETRIES; retry++) {
                if (!autoAnswerRunning) break;

                try {
                    if (retry > 0) {
                        log(`🔄 第${retry + 1}次重试...`, '#fdcb6e');
                        await new Promise(r => setTimeout(r, RETRY_DELAY));
                    } else if (consecutiveErrors >= 3) {
                        log(`⚠️ 连续失败，等待${RATE_LIMIT_DELAY/1000}秒...`, '#fdcb6e');
                        await new Promise(r => setTimeout(r, RATE_LIMIT_DELAY));
                    }

                    log(`📡 开始请求AI...`, '#636e72');
                    response = await callAiApi(prompt);
                    log(`📥 收到AI响应，长度: ${response?.length || 0}`, '#636e72');
                    success = true;
                    consecutiveErrors = 0;
                    break;
                } catch (e) {
                    log(`❌ 请求失败: ${e.message}`, '#ff7675');
                    consecutiveErrors++;

                    if (consecutiveErrors >= 6) {
                        log(`🚫 连续${consecutiveErrors}次失败，自动停止`, '#ff7675');
                        autoAnswerRunning = false;
                        updateAutoAnswerUI();
                        invalidateQuestionCache();
                        updateQuestionGrid(true);
                        return;
                    }
                }
            }

            if (!success || !response) {
                log(`⏭️ 跳过第${originalIndex + 1}题`, '#fdcb6e');
                await new Promise(r => setTimeout(r, REQUEST_DELAY));
                continue;
            }

            const answers = parseAiResponse(response);
            if (!answers || !Array.isArray(answers)) {
                log(`❌ AI返回格式无法解析`, '#ff7675');
                continue;
            }

            for (const item of answers) {
                const qDom = document.querySelector(`.questionLi[data="${item.questionId}"], #question${item.questionId}`);
                if (!qDom) {
                    log(`⚠️ 未找到题目 ${item.questionId}`, '#fdcb6e');
                    continue;
                }

                log(`📋 题目${item.questionId}答案: ${item.answer}`, '#00cec9');

                const type = qDom.getAttribute('typename') || '';
                const ok = await fillAnswer(qDom, item, type);
                if (ok) {
                    totalFilled++;
                    log(`✅ [${totalFilled}/${unansweredFromStart.length}] 题目${item.questionId}已填写`, '#55efc4');
                    invalidateQuestionCache();
                    updateQuestionGrid(true);
                } else {
                    log(`⚠️ 题目${item.questionId}填写失败`, '#fdcb6e');
                }
            }

            if (i < unansweredFromStart.length - 1 && autoAnswerRunning) {
                log(`⏳ 等待${REQUEST_DELAY/1000}秒...`, '#636e72');
                await new Promise(r => setTimeout(r, REQUEST_DELAY));
            }
        }

        log(`🎯 总计已填写 ${totalFilled}/${unansweredFromStart.length} 道题`, '#00b894');
        autoAnswerRunning = false;
        updateAutoAnswerUI();
        invalidateQuestionCache();
        updateQuestionGrid(true);
    }

    function buildPrompt(questions) {
        const lines = questions.map((q, i) => {
            let line = `[${i + 1}] ID:${q.id}`;
            if (q.type) line += ` 题型:${q.type}`;
            line += ` 题目:${q.title}`;
            if (q.options && q.options.length) line += ` 选项:${q.options.join('|')}`;
            return line;
        });
        return `分析以下题目并严格返回JSON数组。必须包含"analysis"字段给出简短理由。\n格式：[{"questionId":"ID","answer":"内容","analysis":"解析"}]\n\n题目：\n${lines.join('\n\n')}`;
    }

    function parseAiResponse(text) {
        if (!text) return null;
        let cleaned = text.replace(/```json\s*/g, '').replace(/```\s*/g, '').trim();
        const firstBracket = cleaned.indexOf('[');
        const lastBracket = cleaned.lastIndexOf(']');
        if (firstBracket === -1 || lastBracket === -1) return null;
        try {
            return JSON.parse(cleaned.substring(firstBracket, lastBracket + 1));
        } catch {
            return null;
        }
    }

    // ============================================================
    //  答案回填
    // ============================================================
    async function fillAnswer(qDom, item, type) {
        if (!qDom || !item) return false;

        if (item.analysis) {
            log(`💡 题${item.questionId}解析: ${item.analysis}`, '#eccc68');
        }

        if (type.includes('填空')) {
            const answers = String(item.answer).split(/[;；\n]/);
            for (let idx = 0; idx < answers.length; idx++) {
                const val = answers[idx].trim();
                if (!val) continue;
                const editorId = `answerEditor${item.questionId}${idx + 1}`;
                const s = document.createElement('script');
                s.textContent = `(function(){ if(window.UE && UE.getEditor("${editorId}")){ UE.getEditor("${editorId}").ready(function(){ this.setContent("${val.replace(/"/g, '\\"')}"); }); } })();`;
                document.body.appendChild(s); s.remove();
                await new Promise(r => setTimeout(r, 300));
            }
            return true;
        }

        if (type.includes('简答') || type.includes('论述') || type.includes('名词解释') || type.includes('问答')) {
            log(`📝 答案: ${item.answer}`, '#74b9ff');
            
            const answerText = String(item.answer);
            
            const simulateTyping = (doc, body) => {
                body.focus();
                doc.execCommand('selectAll', false, null);
                doc.execCommand('delete', false, null);
                doc.execCommand('insertText', false, answerText);
                return body.innerText?.trim()?.length > 0;
            };
            
            const iframe = qDom.querySelector('iframe.edui-editor-iframeholder iframe, .edui-editor-iframeholder iframe, iframe');
            if (iframe) {
                try {
                    const iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
                    const iframeBody = iframeDoc.body;
                    
                    log(`🔍 找到iframe编辑器，模拟输入中...`, '#636e72');
                    
                    const clickEvent = new MouseEvent('click', { bubbles: true, cancelable: true });
                    iframeBody.dispatchEvent(clickEvent);
                    
                    await new Promise(r => setTimeout(r, 200));
                    
                    const success = simulateTyping(iframeDoc, iframeBody);
                    
                    if (success) {
                        iframeBody.dispatchEvent(new Event('input', { bubbles: true }));
                        iframeBody.dispatchEvent(new Event('change', { bubbles: true }));
                        iframeBody.dispatchEvent(new Event('blur', { bubbles: true }));
                        
                        log(`✅ 已模拟输入到iframe编辑器`, '#55efc4');
                        return true;
                    }
                } catch (e) {
                    log(`⚠️ iframe输入失败: ${e.message}`, '#fdcb6e');
                }
            }
            
            const contentEditable = qDom.querySelector('[contenteditable="true"]');
            if (contentEditable) {
                log(`🔍 找到contenteditable编辑器，模拟输入中...`, '#636e72');
                
                contentEditable.click();
                contentEditable.focus();
                
                await new Promise(r => setTimeout(r, 200));
                
                document.execCommand('selectAll', false, null);
                document.execCommand('delete', false, null);
                document.execCommand('insertText', false, answerText);
                
                if (contentEditable.innerText?.trim()?.length > 0) {
                    contentEditable.dispatchEvent(new Event('input', { bubbles: true }));
                    contentEditable.dispatchEvent(new Event('change', { bubbles: true }));
                    contentEditable.dispatchEvent(new Event('blur', { bubbles: true }));
                    
                    log(`✅ 已模拟输入到contenteditable编辑器`, '#55efc4');
                    return true;
                }
            }
            
            const textarea = qDom.querySelector('textarea');
            if (textarea) {
                log(`🔍 找到textarea，模拟输入中...`, '#636e72');
                
                textarea.click();
                textarea.focus();
                
                await new Promise(r => setTimeout(r, 200));
                
                const nativeSetter = Object.getOwnPropertyDescriptor(
                    window.HTMLTextAreaElement.prototype, 'value'
                )?.set;
                if (nativeSetter) {
                    nativeSetter.call(textarea, answerText);
                } else {
                    textarea.value = answerText;
                }
                
                textarea.dispatchEvent(new Event('input', { bubbles: true }));
                textarea.dispatchEvent(new Event('change', { bubbles: true }));
                textarea.dispatchEvent(new KeyboardEvent('keyup', { bubbles: true }));
                textarea.dispatchEvent(new Event('blur', { bubbles: true }));
                
                if (textarea.value.length > 0) {
                    log(`✅ 已模拟输入到textarea`, '#55efc4');
                    return true;
                }
            }
            
            try {
                GM_setClipboard(answerText);
                log(`📋 答案已复制到剪贴板，请手动粘贴`, '#fdcb6e');
                log(`💡 提示：点击输入框后使用 Ctrl+V 粘贴`, '#74b9ff');
                return false;
            } catch (e) {
                log(`⚠️ 无法复制到剪贴板`, '#fdcb6e');
            }
            
            log(`⚠️ 未找到编辑器，答案已在日志中显示`, '#fdcb6e');
            return false;
        }

        const ansStr = String(item.answer).toUpperCase().trim();
        const opts = qDom.querySelectorAll('.answerBg, .answer_item, .options li');
        let filled = false;

        if (type.includes('判断')) {
            for (const opt of opts) {
                const label = opt.innerText?.trim();
                const isCorrect = (ansStr.includes('对') && (label.includes('对') || label.includes('√') || label.includes('正确') || label.includes('A'))) ||
                                  (ansStr.includes('错') && (label.includes('错') || label.includes('×') || label.includes('不正确') || label.includes('B')));
                if (isCorrect) {
                    opt.click();
                    filled = true;
                    break;
                }
            }
        } else {
            for (let i = 0; i < opts.length; i++) {
                const opt = opts[i];
                const label = opt.querySelector('.num_option, .num_option_dx, b')?.innerText?.trim().replace('.', '') ||
                              opt.getAttribute('data') || '';
                if (label && ansStr.includes(label.toUpperCase())) {
                    if (type.includes('多选') && typeof addMultipleChoice === 'function') {
                        addMultipleChoice(opt);
                    } else if (typeof addChoice === 'function') {
                        addChoice(opt);
                    } else {
                        opt.click();
                    }
                    filled = true;
                    await new Promise(r => setTimeout(r, 200));
                }
            }
        }

        return filled;
    }

    // ============================================================
    //  自动答题核心（逐题处理，带重试和限流检测）
    // ============================================================
    const BATCH_SIZE = 1;
    const REQUEST_DELAY = 5000; // 增加到5秒
    const MAX_RETRIES = 3;
    const RETRY_DELAY = 15000; // 重试间隔15秒
    const RATE_LIMIT_DELAY = 30000; // 限流后等待30秒

    async function doAutoAnswer() {
        const questions = detectQuestions();
        const unanswered = questions.filter(q => !q.answered);

        if (!unanswered.length) {
            log('📋 未发现未答题目，所有题目已作答', '#dfe6e9');
            return 0;
        }

        const answeredCount = questions.length - unanswered.length;
        log(`� 共 ${questions.length} 道题，已答 ${answeredCount} 道，未答 ${unanswered.length} 道`, '#74b9ff');
        log(`🔍 将逐题处理未答题目`, '#74b9ff');
        log(`⚙️ 配置: 请求间隔${REQUEST_DELAY/1000}秒, 失败重试${MAX_RETRIES}次, 重试间隔${RETRY_DELAY/1000}秒`, '#636e72');

        let totalFilled = 0;
        let consecutiveErrors = 0;

        for (let i = 0; i < unanswered.length; i++) {
            if (!autoAnswerRunning) {
                log('⏹️ 自动答题已停止', '#fdcb6e');
                break;
            }

            const q = unanswered[i];
            log(`📦 处理第 ${i + 1}/${unanswered.length} 题 (ID: ${q.id})`, '#74b9ff');

            const prompt = buildPrompt([q]);
            let response = null;
            let success = false;

            for (let retry = 0; retry < MAX_RETRIES; retry++) {
                if (!autoAnswerRunning) break;

                try {
                    if (retry > 0) {
                        log(`🔄 第${retry + 1}次重试...`, '#fdcb6e');
                        await new Promise(r => setTimeout(r, RETRY_DELAY));
                    } else if (consecutiveErrors >= 3) {
                        log(`⚠️ 检测到连续失败，等待${RATE_LIMIT_DELAY/1000}秒避免限流...`, '#fdcb6e');
                        await new Promise(r => setTimeout(r, RATE_LIMIT_DELAY));
                    }

                    response = await callAiApi(prompt);
                    success = true;
                    consecutiveErrors = 0;
                    break;
                } catch (e) {
                    log(`❌ 请求失败: ${e.message}`, '#ff7675');
                    consecutiveErrors++;

                    // 检测限流错误
                    const isRateLimit = e.message.includes('429') || 
                                        e.message.includes('rate') || 
                                        e.message.includes('limit') ||
                                        e.message.includes('too many');

                    if (isRateLimit) {
                        log(`🚫 检测到API限流，等待${RATE_LIMIT_DELAY/1000}秒后重试...`, '#fdcb6e');
                        await new Promise(r => setTimeout(r, RATE_LIMIT_DELAY));
                    }

                    if (consecutiveErrors >= 6) {
                        log(`🚫 连续${consecutiveErrors}次失败，自动停止`, '#ff7675');
                        log(`💡 建议：等待5-10分钟后再尝试，或更换API Key`, '#fdcb6e');
                        autoAnswerRunning = false;
                        updateAutoAnswerUI();
                        return -1;
                    }
                }
            }

            if (!success || !response) {
                log(`⏭️ 跳过第${i + 1}题，继续下一题`, '#fdcb6e');
                // 跳过后也等待一段时间
                await new Promise(r => setTimeout(r, REQUEST_DELAY));
                continue;
            }

            const answers = parseAiResponse(response);
            if (!answers || !Array.isArray(answers)) {
                log(`❌ AI返回格式无法解析`, '#ff7675');
                log(`原始响应: ${response.substring(0, 300)}`, '#636e72');
                continue;
            }

            for (const item of answers) {
                const qDom = document.querySelector(`.questionLi[data="${item.questionId}"], #question${item.questionId}, [data-qid="${item.questionId}"]`);
                if (!qDom) {
                    log(`⚠️ 未找到题目 ${item.questionId}`, '#fdcb6e');
                    continue;
                }
                
                // 显示答案内容
                log(`📋 题目${item.questionId}答案: ${item.answer}`, '#00cec9');
                
                const type = qDom.getAttribute('typename') || '';
                const ok = await fillAnswer(qDom, item, type);
                if (ok) {
                    totalFilled++;
                    log(`✅ [${totalFilled}/${unanswered.length}] 题目${item.questionId}已填写`, '#55efc4');
                } else {
                    log(`⚠️ 题目${item.questionId}填写失败`, '#fdcb6e');
                }
            }

            if (i < unanswered.length - 1 && autoAnswerRunning) {
                log(`⏳ 等待${REQUEST_DELAY/1000}秒...`, '#636e72');
                await new Promise(r => setTimeout(r, REQUEST_DELAY));
            }
        }

        log(`🎯 总计已填写 ${totalFilled}/${unanswered.length} 道题`, '#00b894');
        if (autoAnswerRunning) {
            log(`✅ 自动答题完成`, '#00b894');
        }
        return totalFilled;
    }

    async function startAutoAnswerLoop() {
        if (autoAnswerRunning) return;
        autoAnswerRunning = true;
        updateAutoAnswerUI();
        log('🚀 自动答题已启动', '#00b894');

        const loop = async () => {
            if (!autoAnswerRunning) return;
            const result = await doAutoAnswer();
            if (result === -1) {
                log('⚠️ 发生错误，自动答题已停止', '#ff7675');
                stopAutoAnswerLoop();
                return;
            }
            if (autoAnswerRunning && uiSettings.autoNextQuestion) {
                const nextBtn = document.querySelector('.nextDiv a, .next-btn, .btn_next, a[class*="next"]');
                if (nextBtn) {
                    log('➡️ 自动切换下一题...', '#74b9ff');
                    nextBtn.click();
                    autoAnswerTimer = setTimeout(loop, uiSettings.autoAnswerDelay + 2000);
                } else {
                    log('✅ 所有题目已完成，自动答题停止', '#00b894');
                    stopAutoAnswerLoop();
                }
            } else {
                stopAutoAnswerLoop();
            }
        };

        autoAnswerTimer = setTimeout(loop, 500);
    }

    function stopAutoAnswerLoop() {
        autoAnswerRunning = false;
        if (autoAnswerTimer) {
            clearTimeout(autoAnswerTimer);
            autoAnswerTimer = null;
        }
        updateAutoAnswerUI();
        log('⏹️ 自动答题已停止', '#dfe6e9');
    }

    function updateAutoAnswerUI() {
        const btn = document.getElementById('btn-auto-answer');
        if (!btn) return;
        if (autoAnswerRunning) {
            btn.textContent = '⏹️ 停止自动答题';
            btn.style.background = 'linear-gradient(135deg, #e74c3c 0%, #c0392b 100%)';
        } else {
            btn.textContent = '🤖 开始自动答题';
            btn.style.background = 'linear-gradient(135deg, #00b894 0%, #00a085 100%)';
        }
    }

    // ============================================================
    //  日志系统
    // ============================================================
    const log = (msg, color = '#00ff00') => {
        const box = document.getElementById('yan-log');
        if (box) {
            const div = document.createElement('div');
            div.style.color = color;
            const time = new Date().toLocaleTimeString('zh-CN', { hour12: false });
            div.innerText = `[${time}] ${msg}`;
            box.appendChild(div);
            box.scrollTop = box.scrollHeight;
            if (box.children.length > 500) {
                box.removeChild(box.firstChild);
            }
        }
    };

    // ============================================================
    //  解锁粘贴限制
    // ============================================================
    const hookUEditor = () => {
        if (window.UE && window.UE.Editor) {
            const originalFire = window.UE.Editor.prototype.fireEvent;
            window.UE.Editor.prototype.fireEvent = function(type) {
                if (type === 'beforepaste') return;
                return originalFire.apply(this, arguments);
            };
            log("🔓 UEditor粘贴限制已解除");
        } else {
            setTimeout(hookUEditor, 1500);
        }
    };

    const hookPasteEvents = () => {
        document.addEventListener('paste', function(e) {
            e.stopPropagation();
        }, true);

        document.addEventListener('copy', function(e) {
            e.stopPropagation();
        }, true);

        document.addEventListener('cut', function(e) {
            e.stopPropagation();
        }, true);

        document.addEventListener('keydown', function(e) {
            if (e.ctrlKey && (e.key === 'v' || e.key === 'V' || e.key === 'c' || e.key === 'C')) {
                e.stopPropagation();
            }
        }, true);

        log("🔓 全局复制粘贴限制已解除");
    };

    const forceSetValue = (element, value) => {
        if (!element) return false;

        element.focus();

        if (element.tagName === 'TEXTAREA' || element.tagName === 'INPUT') {
            const nativeInputValueSetter = Object.getOwnPropertyDescriptor(
                window.HTMLTextAreaElement.prototype, 'value'
            )?.set || Object.getOwnPropertyDescriptor(
                window.HTMLInputElement.prototype, 'value'
            )?.set;

            if (nativeInputValueSetter) {
                nativeInputValueSetter.call(element, value);
            } else {
                element.value = value;
            }

            element.dispatchEvent(new Event('input', { bubbles: true }));
            element.dispatchEvent(new Event('change', { bubbles: true }));
            element.dispatchEvent(new KeyboardEvent('keyup', { bubbles: true }));
            return true;
        }

        if (element.contentEditable === 'true') {
            element.innerHTML = value.replace(/\n/g, '<br>');

            element.dispatchEvent(new Event('input', { bubbles: true }));
            element.dispatchEvent(new Event('change', { bubbles: true }));
            element.dispatchEvent(new Event('blur', { bubbles: true }));
            return true;
        }

        if (element.tagName === 'IFRAME') {
            try {
                const body = element.contentDocument?.body;
                if (body) {
                    body.innerHTML = value.replace(/\n/g, '<br>');
                    body.dispatchEvent(new Event('input', { bubbles: true }));
                    return true;
                }
            } catch (e) {
                log(`⚠️ iframe访问受限`, '#fdcb6e');
            }
        }

        return false;
    };

    // ============================================================
    //  UI 样式
    // ============================================================
    GM_addStyle(`
        :root {
            --yan-panel-width: ${uiSettings.panelWidth}px;
            --yan-panel-opacity: ${uiSettings.panelOpacity / 100};
            --yan-float-duration: ${uiSettings.floatDuration}s;
            --yan-ball-size: ${uiSettings.ballSize}px;
        }
        #yan-ball {
            position: fixed; left: 20px; top: 20px;
            width: var(--yan-ball-size); height: var(--yan-ball-size);
            background: radial-gradient(circle at 28% 24%, rgba(255,255,255,0.98) 0 8%, rgba(255,255,255,0.38) 10%, rgba(255,255,255,0) 30%),
                radial-gradient(circle at 68% 72%, rgba(31,145,255,0.24) 0 14%, rgba(31,145,255,0) 54%),
                linear-gradient(145deg, #58b9ff 0%, #2d93ff 40%, #0f68ef 100%);
            border-radius: 46% 54% 52% 48% / 44% 42% 58% 56%;
            box-shadow: 0 18px 34px rgba(8,72,170,0.28), inset 0 1px 3px rgba(255,255,255,0.45), inset 0 -10px 18px rgba(0,0,0,0.14);
            cursor: grab; z-index: 9999999; display: flex; align-items: center; justify-content: center;
            color: #fff; font-size: 13px; font-weight: 700; letter-spacing: 0.04em;
            user-select: none; -webkit-user-select: none; touch-action: none; overflow: hidden;
            transition: box-shadow 0.22s ease, filter 0.22s ease;
            animation: yan-morph var(--yan-float-duration) ease-in-out infinite, yan-breathe 3.1s ease-in-out infinite, yan-drift 7.8s ease-in-out infinite;
            will-change: transform, left, top, border-radius;
        }
        #yan-ball::before {
            content: ""; position: absolute; inset: -12%;
            border-radius: 48% 52% 54% 46% / 50% 46% 54% 50%;
            background: radial-gradient(circle at 28% 28%, rgba(255,255,255,0.56) 0 10%, rgba(255,255,255,0.12) 28%, rgba(255,255,255,0) 56%),
                radial-gradient(circle at 68% 72%, rgba(34,141,255,0.32) 0 12%, rgba(34,141,255,0) 60%);
            filter: blur(6px); opacity: 0.9; transform: translate3d(0,0,0);
            animation: yan-swim calc(var(--yan-float-duration)*1.15) ease-in-out infinite;
            pointer-events: none;
        }
        #yan-ball::after {
            content: ""; position: absolute; inset: 12% 16% 50% 16%;
            border-radius: 50%; background: linear-gradient(to bottom, rgba(255,255,255,0.72), rgba(255,255,255,0));
            filter: blur(1px); opacity: 0.95; animation: yan-sheen 2.7s ease-in-out infinite; pointer-events: none;
        }
        #yan-ball span { position: relative; z-index: 1; text-shadow: 0 1px 2px rgba(0,0,0,0.16); }
        #yan-ball:hover { filter: saturate(1.05) brightness(1.03); box-shadow: 0 20px 38px rgba(8,72,170,0.32), inset 0 1px 3px rgba(255,255,255,0.5), inset 0 -10px 18px rgba(0,0,0,0.12); }
        #yan-ball.dragging { cursor: grabbing; animation: none; transform: scale(1.08); }
        #yan-ball.was-dragged { animation: yan-settle 0.22s ease-out; }
        #yan-ball.releasing { animation: yan-release 0.36s cubic-bezier(.2,.8,.2,1); }
        #yan-panel {
            position: fixed; width: var(--yan-panel-width);
            background: rgba(255,255,255,var(--yan-panel-opacity));
            border-radius: 22px; box-shadow: 0 24px 60px rgba(0,0,0,0.18);
            border: 1px solid rgba(255,255,255,0.72); backdrop-filter: blur(14px);
            z-index: 9999998; overflow: hidden; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            opacity: 0; transform: translateY(14px) scale(0.96);
            transition: opacity 220ms ease, transform 260ms cubic-bezier(.2,.9,.2,1);
            pointer-events: none;
        }
        #yan-panel.is-open { opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }
        .yan-panel-shell { display: flex; flex-direction: column; max-height: min(85vh, 800px); }
        .yan-header { padding: 14px 16px 12px; background: linear-gradient(180deg, #fafcff 0%, #eff5ff 100%); border-bottom: 1px solid #e8eef9; }
        .yan-header-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
        .yan-title-wrap { display: flex; flex-direction: column; gap: 6px; }
        .yan-title { font-weight: 800; font-size: 16px; color: #20324a; display: block; letter-spacing: 0.01em; }
        .yan-subtitle { font-size: 12px; color: #62738b; line-height: 1.4; }
        .yan-close { border: none; background: rgba(27,52,89,0.08); color: #20324a; width: 30px; height: 30px; border-radius: 50%; cursor: pointer; flex: 0 0 auto; font-size: 16px; }
        .yan-body { padding: 14px; overflow: auto; }
        .yan-tabs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; padding: 10px 14px 0; }
        .yan-tab {
            border: 1px solid #e6ecf6; background: #f8fbff; color: #42526b;
            border-radius: 999px; padding: 8px 6px; font-size: 11px; font-weight: 800;
            cursor: pointer; text-align: center;
            transition: transform 160ms ease, background 160ms ease, color 160ms ease, border-color 160ms ease;
        }
        .yan-tab:hover { transform: translateY(-1px); background: #eef4ff; border-color: #cfdcf8; }
        .yan-tab.is-active { background: linear-gradient(135deg, #3e76ff 0%, #1a57e8 100%); border-color: transparent; color: #fff; box-shadow: 0 10px 22px rgba(34,89,226,0.18); }
        .yan-page { display: none; animation: yan-page-in 180ms ease-out; }
        .yan-page.is-active { display: block; }
        .yan-section { border: 1px solid #edf1f7; background: #fff; border-radius: 18px; margin-bottom: 12px; overflow: hidden; }
        .yan-section-title { padding: 10px 14px 8px; font-size: 13px; font-weight: 800; color: #21314a; background: linear-gradient(180deg, #fbfcfe 0%, #f7f9fd 100%); border-bottom: 1px solid #edf1f7; letter-spacing: 0.02em; }
        .yan-section-desc { padding: 10px 14px 0; font-size: 12px; line-height: 1.55; color: #718197; }
        .yan-action-grid { display: grid; grid-template-columns: 1fr; gap: 10px; padding: 12px 14px 14px; }
        .yan-action-grid-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; padding: 12px 14px 14px; }
        .yan-btn {
            width: 100%; padding: 13px 16px; border: none; cursor: pointer; font-weight: 700; font-size: 14px;
            color: #eaf1ff; text-align: left; border-radius: 14px;
            box-shadow: 0 8px 18px rgba(0,0,0,0.1);
            transition: transform 160ms ease, box-shadow 160ms ease, filter 160ms ease;
        }
        .yan-btn:hover { transform: translateY(-1px); filter: brightness(1.03); box-shadow: 0 12px 24px rgba(0,0,0,0.14); }
        .yan-btn:active { transform: translateY(0); }
        .yan-btn-sm { padding: 10px 12px; font-size: 12px; }
        #btn-auto-answer { background: linear-gradient(135deg, #00b894 0%, #00a085 100%); }
        .yan-question-grid {
            display: grid;
            grid-template-columns: repeat(5, 1fr);
            gap: 6px;
            padding: 12px 14px 14px;
        }
        .yan-question-cell {
            aspect-ratio: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 8px;
            font-size: 12px;
            font-weight: 700;
            cursor: pointer;
            transition: all 160ms ease;
            border: 1px solid #e6ecf6;
        }
        .yan-question-cell.answered {
            background: linear-gradient(135deg, #00b894 0%, #00a085 100%);
            color: #fff;
            border-color: transparent;
            box-shadow: 0 4px 12px rgba(0, 184, 148, 0.3);
        }
        .yan-question-cell.unanswered {
            background: #f0f2f5;
            color: #636e72;
        }
        .yan-question-cell:hover {
            transform: scale(1.05);
            box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
        }
        .yan-question-cell.active {
            background: linear-gradient(135deg, #0984e3 0%, #6c5ce7 100%);
            color: #fff;
            border-color: transparent;
            box-shadow: 0 4px 12px rgba(9, 132, 227, 0.4);
        }
        #btn-export { background: linear-gradient(135deg, #364a63 0%, #243449 100%); }
        #btn-import { background: linear-gradient(135deg, #25b46b 0%, #18a35d 100%); }
        #btn-reset { background: linear-gradient(135deg, #f59b23 0%, #e77b12 100%); }
        #btn-wizard { background: linear-gradient(135deg, #f8fbff 0%, #eef4ff 100%); color: #243449; border: 1px solid #dbe5fb; box-shadow: 0 8px 18px rgba(25,53,96,0.06); }
        #btn-wizard:hover { color: #1f3357; background: linear-gradient(135deg, #eff4ff 0%, #e4ecff 100%); }
        .yan-settings { display: grid; gap: 12px; padding: 12px 14px 14px; }
        .yan-field { display: grid; gap: 8px; }
        .yan-field-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; font-size: 12px; color: #42526b; }
        .yan-field-label { font-weight: 700; color: #22324a; }
        .yan-field-value { font-variant-numeric: tabular-nums; color: #61738b; }
        .yan-range { width: 100%; margin: 0; accent-color: #3f79ff; }
        .yan-switch { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 14px; border: 1px solid #edf1f7; border-radius: 14px; background: #fbfcfe; }
        .yan-switch small { display: block; color: #7a8797; margin-top: 4px; line-height: 1.4; }
        .yan-switch strong { color: #21314a; }
        .yan-switch input { width: 18px; height: 18px; }
        .yan-input {
            width: 100%; padding: 10px 12px; border: 1px solid #dfe6f1; border-radius: 12px;
            background: #fff; color: #22324a; font-size: 13px; outline: none; font-family: monospace;
            box-sizing: border-box;
        }
        .yan-input:focus { border-color: #3f79ff; box-shadow: 0 0 0 3px rgba(63,121,255,0.12); }
        .yan-input::placeholder { color: #b0bec5; }
        .yan-select {
            width: 100%; padding: 11px 12px; border: 1px solid #dfe6f1; border-radius: 14px;
            background: #fff; color: #22324a; font-weight: 700; outline: none;
            box-sizing: border-box;
        }
        .yan-provider-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; padding: 12px 14px; }
        .yan-provider-btn {
            border: 2px solid #e6ecf6; background: #f8fbff; color: #42526b;
            border-radius: 12px; padding: 8px 4px; font-size: 11px; font-weight: 700;
            cursor: pointer; text-align: center;
            transition: all 160ms ease;
        }
        .yan-provider-btn:hover { background: #eef4ff; border-color: #cfdcf8; transform: translateY(-1px); }
        .yan-provider-btn.is-active { background: linear-gradient(135deg, #3e76ff 0%, #1a57e8 100%); border-color: transparent; color: #fff; box-shadow: 0 6px 14px rgba(34,89,226,0.18); }
        #yan-log {
            height: 180px; background: #20242a; color: #89ff9c; overflow-y: auto;
            padding: 12px; font-size: 12px; font-family: 'Cascadia Code', 'Fira Code', monospace;
            border-radius: 0 0 18px 18px; line-height: 1.6;
        }
        .yan-log-frame { border: 1px solid #edf1f7; border-radius: 18px; overflow: hidden; background: #20242a; }
        .yan-status-bar {
            padding: 8px 14px; background: #f0f4ff; border-radius: 12px;
            font-size: 12px; color: #42526b; display: flex; align-items: center; gap: 8px;
            margin: 8px 14px; border: 1px solid #e6ecf6;
        }
        #yan-search-input {
            font-family: inherit;
            line-height: 1.5;
        }
        #yan-search-result {
            font-family: inherit;
            line-height: 1.6;
            overflow-y: auto;
            max-height: 200px;
        }
        .yan-status-dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
        .yan-status-dot.ok { background: #00b894; box-shadow: 0 0 6px rgba(0,184,148,0.4); }
        .yan-status-dot.warn { background: #fdcb6e; box-shadow: 0 0 6px rgba(253,203,110,0.4); }
        .yan-status-dot.error { background: #ff7675; box-shadow: 0 0 6px rgba(255,118,117,0.4); }
        .yan-status-dot.idle { background: #b2bec3; }
        @keyframes yan-morph { 0%,100%{border-radius:46% 54% 52% 48%/44% 42% 58% 56%;transform:translate3d(0,0,0) rotate(-2deg)} 25%{border-radius:52% 48% 41% 59%/50% 58% 42% 50%;transform:translate3d(0,-4px,0) rotate(1deg)} 50%{border-radius:42% 58% 56% 44%/58% 46% 54% 42%;transform:translate3d(0,2px,0) rotate(2deg)} 75%{border-radius:58% 42% 48% 52%/42% 56% 44% 58%;transform:translate3d(0,-2px,0) rotate(-1deg)} }
        @keyframes yan-swim { 0%,100%{transform:translate3d(-6px,-2px,0) scale(1)} 33%{transform:translate3d(5px,3px,0) scale(1.03)} 66%{transform:translate3d(-2px,5px,0) scale(1.01)} }
        @keyframes yan-sheen { 0%,100%{transform:translate3d(0,0,0) scale(1);opacity:.95} 50%{transform:translate3d(2px,4px,0) scale(.98);opacity:.8} }
        @keyframes yan-breathe { 0%,100%{filter:saturate(1) brightness(1)} 50%{filter:saturate(1.08) brightness(1.03)} }
        @keyframes yan-settle { 0%{transform:scale(1.12)} 70%{transform:scale(.98)} 100%{transform:scale(1)} }
        @keyframes yan-release { 0%{transform:scale(1.05)} 40%{transform:scale(.96)} 100%{transform:scale(1)} }
        @keyframes yan-drift { 0%,100%{filter:hue-rotate(0deg) saturate(1)} 50%{filter:hue-rotate(10deg) saturate(1.08)} }
        @keyframes yan-page-in { from{opacity:0;transform:translateY(6px)} to{opacity:1;transform:translateY(0)} }
        @media (prefers-reduced-motion: reduce) { #yan-ball,#yan-ball::before,#yan-ball::after,#yan-panel{animation:none!important;transition-duration:.01ms!important} }
    `);

    // ============================================================
    //  主界面初始化
    // ============================================================
    function createRangeField(id, label, min, max, step, unit, value) {
        return `<div class="yan-field"><div class="yan-field-head"><span class="yan-field-label">${label}</span><span class="yan-field-value"><span id="${id}-value">${value}</span>${unit}</span></div><input id="${id}" class="yan-range" type="range" min="${min}" max="${max}" step="${step}" value="${value}"></div>`;
    }

    function getProviderStatus() {
        if (!aiConfig.apiUrl) return { cls: 'warn', text: '未配置AI接口' };
        if (!aiConfig.apiKey && !aiConfig.apiUrl.includes('localhost') && !aiConfig.apiUrl.includes('127.0.0.1')) return { cls: 'warn', text: '未配置API Key' };
        return { cls: 'ok', text: `${AI_PROVIDERS.find(p => p.id === aiConfig.provider)?.name || '自定义'} · ${aiConfig.model}` };
    }

    function init() {
        if (document.getElementById('yan-ball')) return;

        const ball = document.createElement('div');
        ball.id = 'yan-ball';
        ball.innerHTML = '<span>AI 答题</span>';
        document.body.appendChild(ball);

        const status = getProviderStatus();

        const panel = document.createElement('div');
        panel.id = 'yan-panel';
        panel.innerHTML = `
            <div class="yan-panel-shell">
                <div class="yan-header">
                    <div class="yan-header-top">
                        <div class="yan-title-wrap">
                            <span class="yan-title">AI答题</span>
                            <span class="yan-subtitle">拖动球体换位置 · 点击打开面板 · 自动识别题目并AI答题</span>
                        </div>
                        <button id="yan-close" class="yan-close" type="button">×</button>
                    </div>
                    <div class="yan-status-bar">
                        <span class="yan-status-dot ${status.cls}"></span>
                        <span>${status.text}</span>
                    </div>
                </div>
                <div class="yan-body">
                    <div class="yan-tabs">
                        <button class="yan-tab is-active" data-page="basic" type="button">答题</button>
                        <button class="yan-tab" data-page="ai" type="button">AI配置</button>
                        <button class="yan-tab" data-page="output" type="button">日志</button>
                        <button class="yan-tab" data-page="settings" type="button">设置</button>
                    </div>

                    <div class="yan-page is-active" data-page-panel="basic">
                        <div class="yan-section">
                            <div class="yan-section-title">🤖 智能答题</div>
                            <div class="yan-section-desc">自动识别页面题目，调用AI生成答案并回填。</div>
                            <div class="yan-action-grid">
                                <button id="btn-auto-answer" class="yan-btn">🤖 开始自动答题</button>
                            </div>
                        </div>
                        <div class="yan-section">
                            <div class="yan-section-title">📊 题目进度</div>
                            <div class="yan-section-desc">点击格子从该题开始答题，绿色=已答，灰色=未答</div>
                            <div id="yan-question-grid" class="yan-question-grid">
                                <div style="grid-column:1/-1;text-align:center;color:#718197;font-size:12px;padding:20px;">等待检测题目...</div>
                            </div>
                        </div>
                        <div class="yan-section">
                            <div class="yan-section-title">📋 手动操作</div>
                            <div class="yan-action-grid-2col">
                                <button id="btn-export" class="yan-btn yan-btn-sm">📤 导出题目</button>
                                <button id="btn-import" class="yan-btn yan-btn-sm">📥 剪贴板回填</button>
                            </div>
                        </div>
                        <div class="yan-section">
                            <div class="yan-section-title">🔍 手动搜题</div>
                            <div class="yan-section-desc">输入题目内容，点击回答获取答案</div>
                            <div class="yan-settings">
                                <div class="yan-field">
                                    <div class="yan-field-head"><span class="yan-field-label">题目内容</span></div>
                                    <textarea id="yan-search-input" class="yan-input" rows="3" placeholder="在此粘贴或输入题目内容..." style="resize:vertical;min-height:60px;"></textarea>
                                </div>
                                <button id="btn-search-answer" class="yan-btn" style="background:linear-gradient(135deg,#e17055 0%,#d63031 100%)">🔍 获取答案</button>
                                <div class="yan-field">
                                    <div class="yan-field-head">
                                        <span class="yan-field-label">AI回答</span>
                                        <button id="btn-copy-answer" class="yan-btn yan-btn-sm" style="width:auto;padding:4px 8px;font-size:11px;background:linear-gradient(135deg,#00b894 0%,#00a085 100%)">📋 复制</button>
                                    </div>
                                    <div id="yan-search-result" class="yan-input" style="min-height:60px;white-space:pre-wrap;word-break:break-all;background:#f8f9fa;color:#333;"></div>
                                </div>
                            </div>
                        </div>
                    </div>

                    <div class="yan-page" data-page-panel="ai">
                        <div class="yan-section">
                            <div class="yan-section-title">🔧 AI 服务商预设</div>
                            <div class="yan-provider-grid">
                                ${AI_PROVIDERS.map(p => `<button class="yan-provider-btn${p.id === aiConfig.provider ? ' is-active' : ''}" data-provider="${p.id}" title="${p.desc}">${p.name}</button>`).join('')}
                            </div>
                        </div>
                        <div class="yan-section">
                            <div class="yan-section-title">⚙️ 接口参数</div>
                            <div class="yan-settings">
                                <div class="yan-field">
                                    <div class="yan-field-head"><span class="yan-field-label">API 地址</span></div>
                                    <input id="yan-ai-url" class="yan-input" type="text" placeholder="https://api.example.com/v1/chat/completions" value="${aiConfig.apiUrl || ''}">
                                </div>
                                <div class="yan-field">
                                    <div class="yan-field-head"><span class="yan-field-label">模型名称</span></div>
                                    <input id="yan-ai-model" class="yan-input" type="text" placeholder="gpt-3.5-turbo / deepseek-chat" value="${aiConfig.model || ''}">
                                </div>
                                <div class="yan-field">
                                    <div class="yan-field-head"><span class="yan-field-label">API Key</span></div>
                                    <input id="yan-ai-key" class="yan-input" type="password" placeholder="sk-xxx... (本地模型可留空)" value="${aiConfig.apiKey || ''}">
                                </div>
                                ${createRangeField('yan-ai-temp', '温度 (越低越精确)', 0, 1, 0.05, '', aiConfig.temperature)}
                                <button id="btn-save-ai" class="yan-btn" style="background:linear-gradient(135deg,#0984e3 0%,#6c5ce7 100%)">💾 保存AI配置</button>
                            </div>
                        </div>
                    </div>

                    <div class="yan-page" data-page-panel="output">
                        <div class="yan-section">
                            <div class="yan-section-title">📋 运行日志</div>
                            <div class="yan-section-desc">显示AI请求、答题结果和错误信息。</div>
                            <div class="yan-log-frame">
                                <div id="yan-log">就绪... 请先配置AI接口</div>
                            </div>
                        </div>
                    </div>

                    <div class="yan-page" data-page-panel="settings">
                        <div class="yan-section">
                            <div class="yan-section-title">⚙️ 通用设置</div>
                            <div class="yan-settings">
                                <button id="btn-wizard" class="yan-btn" type="button">🧭 配置向导</button>
                                ${createRangeField('yan-setting-ball-size', '浮球大小', 52, 92, 1, ' px', uiSettings.ballSize)}
                                ${createRangeField('yan-setting-float-duration', '浮动速度', 2.8, 8, 0.1, ' s', uiSettings.floatDuration.toFixed(1))}
                                ${createRangeField('yan-setting-panel-width', '面板宽度', 320, 520, 10, ' px', uiSettings.panelWidth)}
                                ${createRangeField('yan-setting-panel-opacity', '面板透明度', 85, 100, 1, ' %', uiSettings.panelOpacity)}
                                ${createRangeField('yan-setting-delay', '答题间隔', 500, 5000, 100, ' ms', uiSettings.autoAnswerDelay)}
                                <label class="yan-switch"><div><strong>自动翻页</strong><small>答完后自动进入下一题</small></div><input id="yan-setting-next" type="checkbox" ${uiSettings.autoNextQuestion ? 'checked' : ''}></label>
                                <label class="yan-switch"><div><strong>记住浮球位置</strong><small>关闭后刷新页面回到默认位置</small></div><input id="yan-setting-remember" type="checkbox" ${uiSettings.rememberPosition ? 'checked' : ''}></label>
                                <label class="yan-switch"><div><strong>减少动效</strong><small>适合想要更安静的视觉反馈时开启</small></div><input id="yan-setting-motion" type="checkbox" ${uiSettings.reducedMotion ? 'checked' : ''}></label>
                                <button id="btn-reset" class="yan-btn">↺ 恢复默认参数</button>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        `;
        document.body.appendChild(panel);

        // ---- 向导面板 ----
        const wizardMask = document.createElement('div');
        wizardMask.id = 'yan-wizard-mask';
        wizardMask.style.cssText = 'position:fixed;inset:0;background:rgba(13,22,39,0.42);backdrop-filter:blur(8px);z-index:9999997;opacity:0;pointer-events:none;transition:opacity 220ms ease;';
        wizardMask.innerHTML = `
            <div id="yan-wizard-panel" style="position:fixed;left:50%;top:50%;z-index:9999998;width:min(460px,calc(100vw - 32px));border-radius:24px;background:rgba(255,255,255,0.98);box-shadow:0 26px 70px rgba(0,0,0,0.22);border:1px solid rgba(255,255,255,0.72);overflow:hidden;opacity:0;transform:translate(-50%,-46%) scale(0.96);pointer-events:none;transition:opacity 220ms ease,transform 260ms cubic-bezier(.2,.9,.2,1);">
                <div style="padding:18px 18px 14px;background:linear-gradient(180deg,#fdfefe 0%,#f3f7ff 100%);border-bottom:1px solid #e8eef9;">
                    <div style="display:flex;justify-content:space-between;gap:12px;align-items:flex-start;">
                        <div>
                            <h2 style="margin:0;font-size:17px;font-weight:900;color:#20324a;">配置向导</h2>
                            <p style="margin-top:8px;font-size:12px;line-height:1.6;color:#61738b;">首次使用请按步骤配置AI接口，之后即可自动答题。</p>
                        </div>
                        <button id="yan-wizard-close" style="border:none;background:rgba(27,52,89,0.08);color:#20324a;width:30px;height:30px;border-radius:50%;cursor:pointer;font-size:16px;">×</button>
                    </div>
                </div>
                <div style="padding:16px 18px 18px;">
                    <div style="display:grid;gap:10px;padding:14px;border-radius:18px;background:linear-gradient(180deg,#fbfcff 0%,#f8fbff 100%);border:1px solid #edf1f7;margin-bottom:12px;">
                        <div style="display:flex;align-items:center;gap:10px;font-weight:900;color:#21314a;font-size:14px;">
                            <span style="width:26px;height:26px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;color:#fff;background:linear-gradient(135deg,#3e76ff 0%,#1a57e8 100%);box-shadow:0 10px 20px rgba(34,89,226,0.16);flex:0 0 auto;">1</span> 配置AI接口
                        </div>
                        <p style="margin:0;font-size:13px;line-height:1.65;color:#5d6f86;">切换到「AI配置」页面，选择一个AI服务商（推荐DeepSeek），填入API Key后保存。</p>
                    </div>
                    <div style="display:grid;gap:10px;padding:14px;border-radius:18px;background:linear-gradient(180deg,#fbfcff 0%,#f8fbff 100%);border:1px solid #edf1f7;margin-bottom:12px;">
                        <div style="display:flex;align-items:center;gap:10px;font-weight:900;color:#21314a;font-size:14px;">
                            <span style="width:26px;height:26px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;color:#fff;background:linear-gradient(135deg,#3e76ff 0%,#1a57e8 100%);box-shadow:0 10px 20px rgba(34,89,226,0.16);flex:0 0 auto;">2</span> 开始答题
                        </div>
                        <p style="margin:0;font-size:13px;line-height:1.65;color:#5d6f86;">回到「答题」页面，点击「开始自动答题」即可自动识别题目并AI作答。也可使用「单次答题」手动触发一次。</p>
                    </div>
                    <div style="display:grid;gap:10px;padding:14px;border-radius:18px;background:linear-gradient(180deg,#fbfcff 0%,#f8fbff 100%);border:1px solid #edf1f7;margin-bottom:12px;">
                        <div style="display:flex;align-items:center;gap:10px;font-weight:900;color:#21314a;font-size:14px;">
                            <span style="width:26px;height:26px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;color:#fff;background:linear-gradient(135deg,#3e76ff 0%,#1a57e8 100%);box-shadow:0 10px 20px rgba(34,89,226,0.16);flex:0 0 auto;">3</span> 查看日志
                        </div>
                        <p style="margin:0;font-size:13px;line-height:1.65;color:#5d6f86;">在「日志」页面可以查看AI请求状态、答题结果和错误信息。</p>
                    </div>
                    <div style="display:flex;gap:10px;margin-top:14px;flex-wrap:wrap;">
                        <button id="yan-wizard-start" style="flex:1 1 140px;border:none;border-radius:14px;padding:12px 14px;font-size:13px;font-weight:800;cursor:pointer;color:#fff;background:linear-gradient(135deg,#3e76ff 0%,#1a57e8 100%);box-shadow:0 12px 24px rgba(34,89,226,0.18);">开始使用</button>
                        <button id="yan-wizard-never" style="flex:1 1 140px;border:none;border-radius:14px;padding:12px 14px;font-size:13px;font-weight:800;cursor:pointer;color:#243449;background:#eff4ff;border:1px solid #dbe5fb;">关闭并记住</button>
                    </div>
                </div>
            </div>
        `;
        document.body.appendChild(wizardMask);

        // ============================================================
        //  事件绑定
        // ============================================================
        const pageMap = Array.from(panel.querySelectorAll('.yan-page'));
        const tabButtons = Array.from(panel.querySelectorAll('.yan-tab'));

        const setPage = (page) => {
            tabButtons.forEach(b => b.classList.toggle('is-active', b.dataset.page === page));
            pageMap.forEach(n => n.classList.toggle('is-active', n.dataset.pagePanel === page));
            if (panel.classList.contains('is-open')) positionPanel(ball, panel);
        };

        const openPanelTo = (page) => {
            setPage(page);
            panel.style.display = 'block';
            panel.getBoundingClientRect();
            positionPanel(ball, panel);
            requestAnimationFrame(() => panel.classList.add('is-open'));
        };

        const hidePanel = () => {
            panel.classList.remove('is-open');
            setTimeout(() => { if (!panel.classList.contains('is-open')) panel.style.display = 'none'; }, 260);
        };

        const togglePanel = () => {
            if (panel.classList.contains('is-open')) hidePanel();
            else openPanelTo(uiSettings.autoOpenPage);
        };

        tabButtons.forEach(btn => {
            btn.addEventListener('click', () => {
                setPage(btn.dataset.page);
                uiSettings.autoOpenPage = btn.dataset.page;
                saveUiSettings();
            });
        });

        document.getElementById('yan-close').addEventListener('click', hidePanel);

        // ---- 向导 ----
        const showWizard = () => {
            wizardMask.style.opacity = '1'; wizardMask.style.pointerEvents = 'auto';
            const wp = document.getElementById('yan-wizard-panel');
            wp.style.opacity = '1'; wp.style.transform = 'translate(-50%,-50%) scale(1)'; wp.style.pointerEvents = 'auto';
            GM_setValue(STORAGE_KEYS.wizardSeen, true);
        };
        const hideWizard = () => {
            wizardMask.style.opacity = '0'; wizardMask.style.pointerEvents = 'none';
            const wp = document.getElementById('yan-wizard-panel');
            wp.style.opacity = '0'; wp.style.transform = 'translate(-50%,-46%) scale(0.96)'; wp.style.pointerEvents = 'none';
        };
        document.getElementById('yan-wizard-close').addEventListener('click', hideWizard);
        document.getElementById('yan-wizard-start').addEventListener('click', hideWizard);
        document.getElementById('yan-wizard-never').addEventListener('click', hideWizard);
        wizardMask.addEventListener('click', e => { if (e.target === wizardMask) hideWizard(); });
        document.getElementById('btn-wizard')?.addEventListener('click', showWizard);

        // ---- AI配置 ----
        document.querySelectorAll('.yan-provider-btn').forEach(btn => {
            btn.addEventListener('click', () => {
                document.querySelectorAll('.yan-provider-btn').forEach(b => b.classList.remove('is-active'));
                btn.classList.add('is-active');
                const provider = AI_PROVIDERS.find(p => p.id === btn.dataset.provider);
                if (provider) {
                    aiConfig.provider = provider.id;
                    if (provider.url) document.getElementById('yan-ai-url').value = provider.url;
                    if (provider.model) document.getElementById('yan-ai-model').value = provider.model;
                    aiConfig.apiUrl = provider.url || aiConfig.apiUrl;
                    aiConfig.model = provider.model || aiConfig.model;
                }
            });
        });

        document.getElementById('yan-ai-url').addEventListener('input', e => { aiConfig.apiUrl = e.target.value.trim(); });
        document.getElementById('yan-ai-model').addEventListener('input', e => { aiConfig.model = e.target.value.trim(); });
        document.getElementById('yan-ai-key').addEventListener('input', e => { aiConfig.apiKey = e.target.value.trim(); });

        document.getElementById('yan-ai-temp').addEventListener('input', e => {
            aiConfig.temperature = parseFloat(e.target.value);
            document.getElementById('yan-ai-temp-value').textContent = aiConfig.temperature;
        });

        document.getElementById('btn-save-ai').addEventListener('click', () => {
            saveAiConfig();
            const s = getProviderStatus();
            const statusEl = panel.querySelector('.yan-status-bar');
            if (statusEl) statusEl.innerHTML = `<span class="yan-status-dot ${s.cls}"></span><span>${s.text}</span>`;
            log('💾 AI配置已保存', '#55efc4');
        });

        // ---- 答题按钮 ----
        document.getElementById('btn-auto-answer').addEventListener('click', () => {
            if (autoAnswerRunning) {
                stopAutoAnswerLoop();
            } else {
                startFromIndex = 0;
                startAutoAnswerFromIndex(0);
            }
        });

        // ---- 导出/回填 ----
        document.getElementById('btn-export').addEventListener('click', () => {
            const questions = detectQuestions();
            if (!questions.length) { log('❌ 未检测到题目', '#ff7675'); return; }
            const prompt = buildPrompt(questions);
            GM_setClipboard(prompt);
            log(`✅ 已导出 ${questions.length} 题到剪贴板`, '#55efc4');
        });

        document.getElementById('btn-import').addEventListener('click', async () => {
            try {
                const text = await navigator.clipboard.readText();
                const answers = parseAiResponse(text);
                if (!answers) { log('❌ 剪贴板内容无法解析为JSON', '#ff7675'); return; }
                for (const item of answers) {
                    const qDom = document.querySelector(`.questionLi[data="${item.questionId}"], #question${item.questionId}`);
                    if (!qDom) continue;
                    const type = qDom.getAttribute('typename') || '';
                    await fillAnswer(qDom, item, type);
                    await new Promise(r => setTimeout(r, 300));
                }
                log(`🎯 回填完成`, '#00b894');
            } catch (e) { log('❌ 剪贴板读取失败: ' + e.message, '#ff7675'); }
        });

        // ---- 手动搜题 ----
        document.getElementById('btn-search-answer').addEventListener('click', async () => {
            const input = document.getElementById('yan-search-input');
            const result = document.getElementById('yan-search-result');
            const question = input.value.trim();
            
            if (!question) {
                result.textContent = '❌ 请输入题目内容';
                result.style.color = '#ff7675';
                return;
            }
            
            result.textContent = '🤖 正在请求AI...';
            result.style.color = '#74b9ff';
            
            const prompt = `请回答以下题目，直接给出答案和简短解析。\n\n题目：${question}`;
            
            try {
                const response = await callAiApi(prompt);
                result.textContent = response;
                result.style.color = '#333';
                log('✅ 手动搜题完成', '#55efc4');
            } catch (e) {
                result.textContent = `❌ 请求失败: ${e.message}`;
                result.style.color = '#ff7675';
            }
        });

        document.getElementById('btn-copy-answer').addEventListener('click', () => {
            const result = document.getElementById('yan-search-result');
            const text = result.textContent;
            
            if (!text || text.includes('请输入题目') || text.includes('正在请求')) {
                return;
            }
            
            GM_setClipboard(text);
            
            const btn = document.getElementById('btn-copy-answer');
            const originalText = btn.textContent;
            btn.textContent = '✅ 已复制';
            setTimeout(() => { btn.textContent = originalText; }, 1500);
            
            log('📋 答案已复制到剪贴板', '#55efc4');
        });

        // ---- 设置控件 ----
        const bindRange = (id, key, transform) => {
            const el = document.getElementById(id);
            if (!el) return;
            el.addEventListener('input', e => {
                uiSettings[key] = transform ? transform(e.target.value) : parseFloat(e.target.value);
                const valEl = document.getElementById(`${id}-value`);
                if (valEl) valEl.textContent = typeof uiSettings[key] === 'number' && uiSettings[key] % 1 !== 0 ? uiSettings[key].toFixed(1) : uiSettings[key];
                saveUiSettings();
                applyUiToElements(ball, panel);
            });
        };

        bindRange('yan-setting-ball-size', 'ballSize', v => clamp(Number(v), 52, 92));
        bindRange('yan-setting-float-duration', 'floatDuration', v => clamp(Number(v), 2.8, 8));
        bindRange('yan-setting-panel-width', 'panelWidth', v => clamp(Number(v), 320, 520));
        bindRange('yan-setting-panel-opacity', 'panelOpacity', v => clamp(Number(v), 85, 100));
        bindRange('yan-setting-delay', 'autoAnswerDelay', v => clamp(Number(v), 500, 5000));

        document.getElementById('yan-setting-next')?.addEventListener('change', e => { uiSettings.autoNextQuestion = e.target.checked; saveUiSettings(); });
        document.getElementById('yan-setting-remember')?.addEventListener('change', e => { uiSettings.rememberPosition = e.target.checked; saveUiSettings(); });
        document.getElementById('yan-setting-motion')?.addEventListener('change', e => { uiSettings.reducedMotion = e.target.checked; saveUiSettings(); applyUiToElements(ball, panel); });

        document.getElementById('btn-reset').addEventListener('click', () => {
            uiSettings = { ...DEFAULT_SETTINGS };
            saveUiSettings();
            saveJSON(STORAGE_KEYS.ballPos, {});
            applyUiToElements(ball, panel);
            const pos = getDefaultBallPos();
            applyBallPos(ball, pos.left, pos.top);
            log('↺ 已恢复默认参数', '#fdcb6e');
        });

        // ---- 拖拽 ----
        const drag = { active: false, moved: false, startX: 0, startY: 0, originLeft: 0, originTop: 0 };

        ball.addEventListener('pointerdown', e => {
            if (e.button !== 0) return;
            e.preventDefault();
            drag.active = true; drag.moved = false;
            drag.startX = e.clientX; drag.startY = e.clientY;
            const r = ball.getBoundingClientRect();
            drag.originLeft = r.left; drag.originTop = r.top;
            ball.classList.remove('was-dragged');
            ball.setPointerCapture(e.pointerId);
        });

        ball.addEventListener('pointermove', e => {
            if (!drag.active) return;
            const dx = e.clientX - drag.startX, dy = e.clientY - drag.startY;
            if (!drag.moved && Math.hypot(dx, dy) > 6) { drag.moved = true; ball.classList.add('dragging'); }
            if (!drag.moved) return;
            applyBallPos(ball, drag.originLeft + dx, drag.originTop + dy);
            if (panel.classList.contains('is-open')) positionPanel(ball, panel);
        });

        ball.addEventListener('pointerup', e => {
            if (!drag.active) return;
            drag.active = false;
            try { ball.releasePointerCapture(e.pointerId); } catch {}
            if (drag.moved) {
                saveBallPos(ball);
                ball.classList.remove('dragging');
                ball.classList.add('was-dragged', 'releasing');
                if (panel.classList.contains('is-open')) positionPanel(ball, panel);
                setTimeout(() => ball.classList.remove('was-dragged', 'releasing'), 260);
                return;
            }
            togglePanel();
        });

        ball.addEventListener('pointercancel', () => { drag.active = false; ball.classList.remove('dragging'); });

        window.addEventListener('resize', () => {
            const r = ball.getBoundingClientRect();
            applyBallPos(ball, r.left, r.top);
            if (panel.classList.contains('is-open')) positionPanel(ball, panel);
        });

        // ---- 初始化位置和样式 ----
        applyUiToElements(ball, panel);
        const pos = loadBallPos() || getDefaultBallPos();
        applyBallPos(ball, pos.left, pos.top);

        if (!GM_getValue(STORAGE_KEYS.wizardSeen, false)) {
            setTimeout(showWizard, 500);
        }

        log('🚀 学习通AI答题助手已加载 v1.0.0', '#55efc4');
    }

    // ============================================================
    //  UI 辅助
    // ============================================================
    function getDefaultBallPos() {
        return { left: DEFAULT_MARGIN, top: Math.max(DEFAULT_MARGIN, window.innerHeight - uiSettings.ballSize - 80) };
    }

    function loadBallPos() {
        if (!uiSettings.rememberPosition) return null;
        const p = safeParse(GM_getValue(STORAGE_KEYS.ballPos, ''));
        return p && Number.isFinite(p.left) && Number.isFinite(p.top) ? p : null;
    }

    function saveBallPos(ball) {
        if (!uiSettings.rememberPosition) return;
        const r = ball.getBoundingClientRect();
        saveJSON(STORAGE_KEYS.ballPos, { left: Math.round(r.left), top: Math.round(r.top) });
    }

    function applyBallPos(ball, left, top) {
        const s = uiSettings.ballSize;
        const maxL = Math.max(DEFAULT_MARGIN, window.innerWidth - s - DEFAULT_MARGIN);
        const maxT = Math.max(DEFAULT_MARGIN, window.innerHeight - s - DEFAULT_MARGIN);
        ball.style.left = `${clamp(left, DEFAULT_MARGIN, maxL)}px`;
        ball.style.top = `${clamp(top, DEFAULT_MARGIN, maxT)}px`;
        ball.style.right = 'auto'; ball.style.bottom = 'auto';
    }

    function positionPanel(ball, panel) {
        const bR = ball.getBoundingClientRect();
        const pR = panel.getBoundingClientRect();
        const gap = 14;
        let left = bR.left, top = bR.top - pR.height - gap;
        const below = top < DEFAULT_MARGIN;
        if (below) top = bR.bottom + gap;
        left = clamp(left, DEFAULT_MARGIN, Math.max(DEFAULT_MARGIN, window.innerWidth - pR.width - DEFAULT_MARGIN));
        top = clamp(top, DEFAULT_MARGIN, Math.max(DEFAULT_MARGIN, window.innerHeight - pR.height - DEFAULT_MARGIN));
        panel.style.left = `${left}px`; panel.style.top = `${top}px`; panel.style.bottom = 'auto';
        panel.style.transformOrigin = below ? 'left top' : 'left bottom';
    }

    function applyUiToElements(ball, panel) {
        const s = uiSettings.ballSize;
        ball.style.width = `${s}px`; ball.style.height = `${s}px`;
        ball.style.fontSize = `${clamp(Math.round(s * 0.2), 11, 16)}px`;
        ball.style.setProperty('--yan-float-duration', `${uiSettings.floatDuration}s`);
        ball.style.animation = uiSettings.reducedMotion ? 'none' : `yan-morph ${uiSettings.floatDuration}s ease-in-out infinite, yan-breathe 3.1s ease-in-out infinite`;
        document.documentElement.style.setProperty('--yan-panel-width', `${uiSettings.panelWidth}px`);
        document.documentElement.style.setProperty('--yan-panel-opacity', `${uiSettings.panelOpacity / 100}`);
    }

    // ============================================================
    //  启动
    // ============================================================
    hookUEditor();
    hookPasteEvents();
    
    const startUpdateGrid = () => {
        const grid = document.getElementById('yan-question-grid');
        if (grid && typeof updateQuestionGrid === 'function') {
            updateQuestionGrid(true);
        }
    };
    
    // 初始化并立即检测
    init();
    
    // 页面加载后立即开始检测题目
    setTimeout(() => {
        startUpdateGrid();
        log('🔍 正在检测页面题目...', '#74b9ff');
    }, 1000);
    
    // 定期更新
    setInterval(init, 5000);
    setInterval(startUpdateGrid, 10000);
})();