// ==UserScript==
// @name         云南开放大学-暴力自动阅读小小站
// @namespace    http://scriptcat.org/
// @version      2.7.0
// @description  支持视频自动播放 + PDF简单自动停留阅读等，验证平台是否“只需打开停留即可完成”，可支持倍速播放。过程中可能会有作业+考试+章节+期末考试+下线考试等资料都可以反馈小小站1077472126
// @match        https://teach.ynou.edu.cn/*
// @grant        none
// @run-at       document-idle
// @grant        GM_getResourceText
// @grant        GM_getValue
// @grant        GM_info
// @grant        GM_setValue
// @grant        GM_xmlhttpRequest
// @grant        unsafeWindow
// @run-at       document-start
// @antifeature  ads      课程解答
// @license MIT
// ==/UserScript==

(function () {
  'use strict';

  const PANEL_ID = '__course_list_panel_v270__';
  const HIGHLIGHT_CLASS = '__course_list_highlight_v270__';

  const STORAGE_KEY = '__clp_v270_progress__';
  const STORAGE_CONFIG_KEY = '__clp_v270_config__';

  let courseItems = [];
  let filteredItems = [];
  let statusText = '就绪';

  let monitorTimer = null;
  let selectionObserver = null;

  let panelCollapsed = false;
  let lastSelectedId = '';
  let lastVideoSrc = '';
  let lastPdfSrc = '';
  let currentVideoBound = null;
  let currentBoundDoc = null;

  let autoNextEnabled = true;
  let autoLocateCurrent = true;
  let keywordCache = '';
  let isAutoAdvancing = false;

  let lastEndedToken = '';
  let lastNearEndToken = '';

  let playbackRate = 1.0;
  let progressStore = {};
  let rangeStart = '';
  let rangeEnd = '';
  let resumeEnabled = true;

  let pdfSimpleEnabled = true;
  let pdfReadSeconds = 30;
  let pdfTimerToken = '';
  let pdfTimerStartedAt = 0;
  let pdfTimerLeft = 0;
  let pdfTimerHandle = null;

  let saveProgressThrottle = 0;
  let activeResumeToken = '';
  let lastScanAt = 0;

  let dragState = {
    dragging: false,
    startX: 0,
    startY: 0,
    startLeft: 0,
    startTop: 0
  };

  function getText(el) {
    if (!el) return '';
    const direct = (el.innerText || el.textContent || '').replace(/\s+/g, ' ').trim();
    if (direct) return direct;

    const attrs = [
      el.getAttribute?.('title'),
      el.getAttribute?.('aria-label'),
      el.getAttribute?.('alt'),
      el.getAttribute?.('data-title'),
      el.getAttribute?.('data-name')
    ].filter(Boolean);

    return attrs.join(' ').replace(/\s+/g, ' ').trim();
  }

  function getAnchorDisplayText(a, index = 0) {
    if (!a) return `第${index + 1}项`;

    const candidates = [
      a.getAttribute('title'),
      a.getAttribute('aria-label'),
      a.getAttribute('data-title'),
      a.getAttribute('data-name'),
      getText(a)
    ];

    const li = a.closest('li');
    const parent = a.parentElement;

    if (li) {
      candidates.push(li.getAttribute?.('title'));
      candidates.push(getText(li));
    }
    if (parent) {
      candidates.push(parent.getAttribute?.('title'));
      candidates.push(getText(parent));
    }

    let text = candidates
      .filter(Boolean)
      .map(x => String(x).replace(/\s+/g, ' ').trim())
      .find(x => x && x.length > 0);

    if (!text) text = `第${index + 1}项`;
    if (text.length > 120) text = text.slice(0, 120).trim();
    return text;
  }

  function escapeHtml(str) {
    return String(str || '')
      .replace(/&/g, '&')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#39;');
  }

  function wait(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  function clamp(n, min, max) {
    return Math.max(min, Math.min(max, n));
  }

  function toInt(v) {
    const n = parseInt(v, 10);
    return Number.isFinite(n) ? n : 0;
  }

  function hasNumberPrefix(text) {
    return /^\d+[/.\-、()（）]?\s*/.test(String(text || '').trim());
  }

  function loadJson(key, fallback) {
    try {
      const raw = localStorage.getItem(key);
      return raw ? JSON.parse(raw) : fallback;
    } catch {
      return fallback;
    }
  }

  function saveJson(key, data) {
    try {
      localStorage.setItem(key, JSON.stringify(data));
    } catch (e) {
      console.warn('localStorage 保存失败:', e);
    }
  }

  function loadConfig() {
    const cfg = loadJson(STORAGE_CONFIG_KEY, {});
    playbackRate = Number(cfg.playbackRate || 1.0);
    rangeStart = cfg.rangeStart ?? '';
    rangeEnd = cfg.rangeEnd ?? '';
    autoNextEnabled = cfg.autoNextEnabled ?? true;
    autoLocateCurrent = cfg.autoLocateCurrent ?? true;
    keywordCache = cfg.keywordCache ?? '';
    resumeEnabled = cfg.resumeEnabled ?? true;
    panelCollapsed = cfg.panelCollapsed ?? false;
    pdfSimpleEnabled = cfg.pdfSimpleEnabled ?? true;
    pdfReadSeconds = Number(cfg.pdfReadSeconds || 30);
  }

  function saveConfig() {
    saveJson(STORAGE_CONFIG_KEY, {
      playbackRate,
      rangeStart,
      rangeEnd,
      autoNextEnabled,
      autoLocateCurrent,
      keywordCache,
      resumeEnabled,
      panelCollapsed,
      pdfSimpleEnabled,
      pdfReadSeconds
    });
  }

  function loadProgressStore() {
    progressStore = loadJson(STORAGE_KEY, {});
  }

  function saveProgressStore() {
    saveJson(STORAGE_KEY, progressStore);
  }

  function setStatus(text) {
    statusText = text;
    const el = document.getElementById('__clp_status__');
    if (el) el.textContent = text;
  }

  function isVisible(el, doc = document) {
    if (!el) return false;
    try {
      const rect = el.getBoundingClientRect();
      const style = (doc.defaultView || window).getComputedStyle(el);
      return style.display !== 'none' &&
        style.visibility !== 'hidden' &&
        style.opacity !== '0' &&
        rect.width > 8 &&
        rect.height > 8;
    } catch {
      return false;
    }
  }

  function removeOldHighlight() {
    document.querySelectorAll('.' + HIGHLIGHT_CLASS).forEach(el => {
      el.classList.remove(HIGHLIGHT_CLASS);
    });
  }

  function highlightElement(el) {
    if (!el) return;
    removeOldHighlight();
    el.classList.add(HIGHLIGHT_CLASS);
    try {
      el.scrollIntoView({ behavior: 'smooth', block: 'center' });
    } catch {}
  }

  function isCatalogPage() {
    return !!document.querySelector('.r-tree.dTree2') ||
      !!document.querySelector('a[onclick*="playFile"]') ||
      !!document.querySelector('a[href*="playVideo"]') ||
      !!document.querySelector('iframe[src*="pdfjs/web/viewer.html"]');
  }

  function isPlayVideoPage() {
    return /\/play\/playVideo\.action/i.test(location.href);
  }

  function getPageMode() {
    if (isCatalogPage()) return 'catalog';
    if (isPlayVideoPage()) return 'player';
    return 'unknown';
  }

  function getCurrentSelectedAnchor() {
    const selectors = [
      '.r-tree.dTree2 a.selected',
      '.r-tree.dTree2 a.curSelectedNode',
      '.r-tree.dTree2 a.nodeSel',
      'a.selected',
      'li.current a',
      'li.active a',
      'a[aria-current="page"]'
    ];
    for (const sel of selectors) {
      const el = document.querySelector(sel);
      if (el) return el;
    }
    return null;
  }

  function getVideoRootLi() {
    const spans = [...document.querySelectorAll('.r-tree.dTree2 li.parent_li > span.parent_tit, span.parent_tit')];
    for (const span of spans) {
      const text = getText(span);
      if (text.includes('视频课堂') || text.includes('视频') || text.includes('章节辅导') || text.includes('课程资源')) {
        return span.closest('li.parent_li, li');
      }
    }
    return null;
  }

  function uniqueBy(arr, keyFn) {
    const map = new Map();
    arr.forEach(item => {
      const key = keyFn(item);
      if (!map.has(key)) map.set(key, item);
    });
    return [...map.values()];
  }

  function getSameOriginDocsLevel1() {
    const list = [{ doc: document, path: 'top', frame: null }];
    const iframes = [...document.querySelectorAll('iframe, frame')];
    for (let i = 0; i < iframes.length; i++) {
      const f = iframes[i];
      try {
        const doc = f.contentDocument || f.contentWindow?.document;
        if (doc) {
          list.push({ doc, path: `frame${i}`, frame: f });
        }
      } catch {}
    }
    return list;
  }

  function getVisibleVideoDetail() {
    const docs = getSameOriginDocsLevel1();
    let fallback = null;

    for (const ctx of docs) {
      let videos = [];
      try {
        videos = [...ctx.doc.querySelectorAll('video')];
      } catch {}

      const visible = videos.filter(v => isVisible(v, ctx.doc));
      if (visible.length) {
        return {
          video: visible[0],
          doc: ctx.doc,
          frame: ctx.frame,
          source: ctx.path,
          visible: true
        };
      }

      if (!fallback && videos.length) {
        fallback = {
          video: videos[0],
          doc: ctx.doc,
          frame: ctx.frame,
          source: ctx.path,
          visible: false
        };
      }
    }

    return fallback || { video: null, doc: document, frame: null, source: 'none', visible: false };
  }

  function getVisiblePdfDetail() {
    const candidates = [...document.querySelectorAll('iframe, embed, object')];
    const visibleCandidates = candidates.filter(el => {
      const src = el.getAttribute('src') || el.getAttribute('data') || '';
      return /pdfjs\/web\/viewer\.html|\.pdf(\?|$)/i.test(src) && isVisible(el);
    });

    if (visibleCandidates.length) {
      const el = visibleCandidates[0];
      return {
        element: el,
        src: el.getAttribute('src') || el.getAttribute('data') || '',
        tag: el.tagName.toLowerCase(),
        visible: true
      };
    }

    const any = candidates.find(el => {
      const src = el.getAttribute('src') || el.getAttribute('data') || '';
      return /pdfjs\/web\/viewer\.html|\.pdf(\?|$)/i.test(src);
    });

    if (any) {
      return {
        element: any,
        src: any.getAttribute('src') || any.getAttribute('data') || '',
        tag: any.tagName.toLowerCase(),
        visible: false
      };
    }

    return { element: null, src: '', tag: '', visible: false };
  }

  function getVisibleVideo() {
    return getVisibleVideoDetail().video || null;
  }

  function getCurrentContentInfo() {
    const videoDetail = getVisibleVideoDetail();
    if (videoDetail.video) {
      const video = videoDetail.video;
      const currentTime = Number(video.currentTime || 0);
      const duration = Number(video.duration || 0);
      const progress = duration > 0 ? (currentTime / duration) * 100 : 0;
      return {
        type: 'video',
        exists: true,
        src: video.currentSrc || video.src || '',
        paused: !!video.paused,
        muted: !!video.muted,
        currentTime,
        duration,
        progress,
        ended: !!video.ended,
        readyState: Number(video.readyState || 0),
        source: videoDetail.source || 'top'
      };
    }

    const pdfDetail = getVisiblePdfDetail();
    if (pdfDetail.element) {
      return {
        type: 'pdf',
        exists: true,
        src: pdfDetail.src || '',
        paused: false,
        muted: false,
        currentTime: 0,
        duration: 0,
        progress: 0,
        ended: false,
        readyState: 1,
        source: pdfDetail.tag || 'iframe'
      };
    }

    return {
      type: 'none',
      exists: false,
      src: '',
      paused: true,
      muted: false,
      currentTime: 0,
      duration: 0,
      progress: 0,
      ended: false,
      readyState: 0,
      source: 'none'
    };
  }

  async function waitForAnyVideo(timeout = 12000) {
    const start = Date.now();
    while (Date.now() - start < timeout) {
      const detail = getVisibleVideoDetail();
      if (detail.video) return detail;
      await wait(500);
    }
    return { video: null, doc: document, frame: null, source: 'timeout', visible: false };
  }

  function formatTime(sec) {
    if (!Number.isFinite(sec)) return '--:--';
    const s = Math.floor(sec % 60);
    const m = Math.floor((sec / 60) % 60);
    const h = Math.floor(sec / 3600);
    if (h > 0) return `${String(h).padStart(2, '0')}:${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`;
    return `${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`;
  }

  function getVideoInfo(video = null) {
    const detail = getVisibleVideoDetail();
    const target = video || detail.video;
    if (!target) {
      return {
        exists: false,
        src: '',
        paused: true,
        muted: false,
        currentTime: 0,
        duration: 0,
        ended: false,
        readyState: 0,
        progress: 0,
        playbackRate,
        source: detail.source,
        inIframe: !!detail.frame
      };
    }

    const currentTime = Number(target.currentTime || 0);
    const duration = Number(target.duration || 0);
    const progress = duration > 0 ? (currentTime / duration) * 100 : 0;

    return {
      exists: true,
      src: target.currentSrc || target.src || '',
      paused: !!target.paused,
      muted: !!target.muted,
      currentTime,
      duration,
      ended: !!target.ended,
      readyState: Number(target.readyState || 0),
      progress,
      playbackRate: Number(target.playbackRate || 1),
      source: detail.source || 'top',
      inIframe: !!detail.frame
    };
  }

  function getCourseKey(item) {
    if (!item) return '';
    return String(item.id || item.dataId || item.text || item.index || location.href);
  }

  function getCurrentSelectedItem() {
    const current = getCurrentSelectedAnchor();
    if (!current) return null;
    return courseItems.find(item => item.anchor === current || item.id === current.id) || null;
  }

  function getCurrentPseudoItem() {
    const current = getCurrentSelectedItem();
    if (current) return current;
    const title = document.title || '当前内容';
    const params = new URLSearchParams(location.search);
    return {
      index: 1,
      text: title,
      shortText: title,
      id: location.pathname + location.search,
      dataId: params.get('courseId') || params.get('ksId') || '',
      anchor: null,
      element: null,
      resourceType: getCurrentContentInfo().type
    };
  }

  function getCurrentCourseProgress() {
    const current = getCurrentSelectedItem() || getCurrentPseudoItem();
    if (!current) return null;
    return progressStore[getCourseKey(current)] || null;
  }

  function detectAnchorResourceType(a, text = '') {
    const href = a.getAttribute('href') || '';
    const onclick = a.getAttribute('onclick') || '';
    const mix = `${href} ${onclick} ${text}`.toLowerCase();

    if (/playfile|playvideo/.test(mix)) return 'video';
    if (/pdfjs\/web\/viewer\.html|\.pdf(\?|$)/i.test(href)) return 'pdf';
    if (/pdf|讲义|教材|文档|附件|参考答案/.test(mix) && href) return 'pdf';
    return 'unknown';
  }

  function buildCandidateAnchors() {
    const selectors = [
      'a[onclick*="playFile"]',
      'a[href*="playVideo"]',
      'a[href*="playFile"]',
      'a[href*="pdfjs/web/viewer.html"]',
      'a[href$=".pdf"]',
      'a[href*=".pdf?"]',
      '.r-tree.dTree2 a',
      'li a'
    ];

    let all = [];
    selectors.forEach(sel => {
      try {
        all = all.concat([...document.querySelectorAll(sel)]);
      } catch {}
    });

    return uniqueBy(all, a => `${a.id}|${a.getAttribute('href') || ''}|${a.getAttribute('onclick') || ''}|${getText(a)}|${a.getAttribute('title') || ''}`);
  }

  function findCourseItems() {
    const root = getVideoRootLi();
    let anchors = [];
    let globalAnchors = buildCandidateAnchors();

    if (root) {
      try {
        anchors = [...root.querySelectorAll('a[onclick*="playFile"], a[href*="playVideo"], a[href*="playFile"], a[href*="pdfjs/web/viewer.html"], a[href$=".pdf"], a[href*=".pdf?"], a')];
      } catch (e) {
        console.warn('root query 失败:', e);
      }
    }

    if (!anchors.length) anchors = globalAnchors;

    anchors = uniqueBy(anchors, a => `${a.id}|${a.getAttribute('href') || ''}|${a.getAttribute('onclick') || ''}|${a.getAttribute('title') || ''}|${getText(a)}`);

    const mapped = anchors.map((a, idx) => {
      const text = getAnchorDisplayText(a, idx);
      const onclick = a.getAttribute('onclick') || '';
      const href = a.getAttribute('href') || '';
      const resourceType = detectAnchorResourceType(a, text);

      const score =
        (onclick.includes('playFile') ? 5 : 0) +
        (/playVideo|playFile/i.test(href) ? 4 : 0) +
        (/pdfjs\/web\/viewer\.html|\.pdf(\?|$)/i.test(href) ? 4 : 0) +
        (hasNumberPrefix(text) ? 3 : 0) +
        ((text.includes('视频') || text.includes('第') || text.includes('参考答案') || text.includes('讲义')) ? 1 : 0);

      return {
        index: idx + 1,
        text: text || `第${idx + 1}项`,
        shortText: text || `第${idx + 1}项`,
        id: a.id || `auto_${idx}`,
        dataId: a.dataset.id || '',
        onclick,
        href,
        visible: isVisible(a),
        active:
          a.classList.contains('selected') ||
          a.classList.contains('active') ||
          a.classList.contains('curSelectedNode') ||
          a.classList.contains('nodeSel'),
        anchor: a,
        element: a.closest('li') || a,
        score,
        resourceType
      };
    }).filter(item => {
      if (item.resourceType === 'video') return true;
      if (item.resourceType === 'pdf') return true;
      if (item.score >= 4) return true;
      if (item.text && hasNumberPrefix(item.text)) return true;
      return false;
    });

    const finalItems = uniqueBy(mapped, item => `${item.text}|${item.onclick}|${item.href}`).map((item, idx) => ({
      ...item,
      index: idx + 1,
      progressInfo: progressStore[getCourseKey(item)] || null
    }));

    console.log('[findCourseItems] rootFound=', !!root);
    console.log('[findCourseItems] rootAnchors=', anchors.length);
    console.log('[findCourseItems] globalAnchors=', globalAnchors.length);
    console.log('[findCourseItems] finalItems=', finalItems.length, finalItems.slice(0, 10));

    return finalItems;
  }

  function findItemByIndex(index) {
    return courseItems.find(x => x.index === index);
  }

  function getRangeNormalized() {
    const start = toInt(rangeStart);
    const end = toInt(rangeEnd);
    return { start: start > 0 ? start : 0, end: end > 0 ? end : 0 };
  }

  function inPlayRange(item) {
    if (!item) return false;
    const { start, end } = getRangeNormalized();
    if (start > 0 && item.index < start) return false;
    if (end > 0 && item.index > end) return false;
    return true;
  }

  function getNextItemFromCurrent() {
    const current = getCurrentSelectedItem();
    if (!current) return null;

    const { start, end } = getRangeNormalized();

    if (start > 0 && current.index < start) {
      return findItemByIndex(start) || null;
    }

    const next = courseItems.find(x => x.index === current.index + 1) || null;
    if (!next) return null;
    if (end > 0 && next.index > end) return null;
    return next;
  }

  function updateOptionUI() {
    const autoNext = document.getElementById('__clp_auto_next__');
    const autoLocate = document.getElementById('__clp_auto_locate__');
    const resumeEl = document.getElementById('__clp_resume_enabled__');
    const rateEl = document.getElementById('__clp_rate__');
    const rangeStartEl = document.getElementById('__clp_range_start__');
    const rangeEndEl = document.getElementById('__clp_range_end__');
    const pdfSimpleEl = document.getElementById('__clp_pdf_simple__');
    const pdfSecondsEl = document.getElementById('__clp_pdf_seconds__');

    if (autoNext) autoNext.checked = autoNextEnabled;
    if (autoLocate) autoLocate.checked = autoLocateCurrent;
    if (resumeEl) resumeEl.checked = resumeEnabled;
    if (rateEl) rateEl.value = String(playbackRate);
    if (rangeStartEl) rangeStartEl.value = rangeStart;
    if (rangeEndEl) rangeEndEl.value = rangeEnd;
    if (pdfSimpleEl) pdfSimpleEl.checked = pdfSimpleEnabled;
    if (pdfSecondsEl) pdfSecondsEl.value = String(pdfReadSeconds);

    const catalogOnlyEls = document.querySelectorAll('[data-catalog-only="1"]');
    catalogOnlyEls.forEach(el => {
      el.style.display = courseItems.length > 0 ? '' : 'none';
    });
  }

  function applyPlaybackRate(video = null) {
    const target = video || getVisibleVideo();
    if (!target) return;
    try {
      target.playbackRate = playbackRate;
    } catch (e) {
      console.warn('设置倍速失败:', e);
    }
  }

  function saveCurrentProgress(force = false) {
    const now = Date.now();
    if (!force && now - saveProgressThrottle < 1500) return;
    saveProgressThrottle = now;

    const current = getCurrentSelectedItem() || getCurrentPseudoItem();
    if (!current) return;

    const content = getCurrentContentInfo();
    if (content.type === 'video') {
      if (!Number.isFinite(content.currentTime) || content.currentTime <= 0) return;
      progressStore[getCourseKey(current)] = {
        index: current.index || 1,
        text: current.text || document.title || '当前视频',
        currentTime: content.currentTime,
        duration: content.duration || 0,
        progress: content.progress || 0,
        src: content.src || '',
        updatedAt: Date.now(),
        completed: content.ended || (content.duration > 0 && content.progress >= 99.5),
        pageMode: getPageMode(),
        pageUrl: location.href,
        resourceType: 'video'
      };
      saveProgressStore();
      return;
    }

    if (content.type === 'pdf') {
      progressStore[getCourseKey(current)] = {
        index: current.index || 1,
        text: current.text || document.title || '当前PDF',
        currentTime: pdfTimerStartedAt ? Math.max(0, (Date.now() - pdfTimerStartedAt) / 1000) : 0,
        duration: Number(pdfReadSeconds || 0),
        progress: pdfReadSeconds > 0 && pdfTimerStartedAt ? Math.min(100, ((Date.now() - pdfTimerStartedAt) / 1000 / pdfReadSeconds) * 100) : 0,
        src: content.src || '',
        updatedAt: Date.now(),
        completed: false,
        pageMode: getPageMode(),
        pageUrl: location.href,
        resourceType: 'pdf'
      };
      saveProgressStore();
    }
  }

  function markCurrentCompleted(extra = {}) {
    const item = getCurrentSelectedItem() || getCurrentPseudoItem();
    if (!item) return;

    const content = getCurrentContentInfo();
    const isPdf = content.type === 'pdf' || item.resourceType === 'pdf';

    progressStore[getCourseKey(item)] = {
      index: item.index || 1,
      text: item.text || document.title || '当前内容',
      currentTime: isPdf ? Number(pdfReadSeconds || 0) : (content.duration || content.currentTime || 0),
      duration: isPdf ? Number(pdfReadSeconds || 0) : (content.duration || 0),
      progress: 100,
      src: content.src || '',
      updatedAt: Date.now(),
      completed: true,
      pageMode: getPageMode(),
      pageUrl: location.href,
      resourceType: isPdf ? 'pdf' : 'video',
      ...extra
    };
    saveProgressStore();
  }

  async function restoreProgressForCurrent(video = null) {
    if (!resumeEnabled) return;
    const targetVideo = video || getVisibleVideo();
    if (!targetVideo) return;

    const item = getCurrentSelectedItem() || getCurrentPseudoItem();
    if (!item) return;

    const rec = progressStore[getCourseKey(item)];
    if (!rec || rec.resourceType !== 'video' || !Number.isFinite(rec.currentTime) || rec.currentTime <= 0 || rec.completed) return;

    const token = `${getCourseKey(item)}|${targetVideo.currentSrc || targetVideo.src || ''}`;
    if (activeResumeToken === token) return;

    const duration = Number(targetVideo.duration || 0);
    if (duration > 0 && rec.currentTime >= duration - 2) return;

    try {
      activeResumeToken = token;
      await wait(300);
      const targetTime = Math.max(0, rec.currentTime - 1);
      if (targetTime > 0) {
        targetVideo.currentTime = targetTime;
        setStatus(`已恢复断点：${item.text} -> ${formatTime(targetTime)}`);
        updateVideoInfoUI();
      }
    } catch (e) {
      console.warn('恢复断点失败:', e);
    }
  }

  async function tryPlayVideo(video = null) {
    const targetVideo = video || getVisibleVideo();
    if (!targetVideo) return { ok: false, reason: '未找到 video 元素' };

    applyPlaybackRate(targetVideo);

    try {
      if (!targetVideo.paused) return { ok: true, reason: '视频已在播放' };
      await targetVideo.play();
      applyPlaybackRate(targetVideo);
      return { ok: true, reason: 'play() 成功' };
    } catch {
      try {
        targetVideo.muted = true;
        await targetVideo.play();
        applyPlaybackRate(targetVideo);
        return { ok: true, reason: 'muted + play() 成功' };
      } catch {
        return { ok: false, reason: '浏览器拦截自动播放或站点脚本干预' };
      }
    }
  }

  function stopPdfCountdown() {
    if (pdfTimerHandle) {
      clearInterval(pdfTimerHandle);
      pdfTimerHandle = null;
    }
    pdfTimerToken = '';
    pdfTimerStartedAt = 0;
    pdfTimerLeft = 0;
  }

  function startPdfCountdown(item, src = '') {
    if (!pdfSimpleEnabled || !autoNextEnabled || !item) return;

    const token = `${item.index}|${item.id}|${src || item.href || ''}|${pdfReadSeconds}`;
    if (pdfTimerToken === token && pdfTimerHandle) return;

    stopPdfCountdown();

    pdfTimerToken = token;
    pdfTimerStartedAt = Date.now();
    pdfTimerLeft = pdfReadSeconds;

    setStatus(`PDF 简单阅读计时开始：${item.text}（${pdfReadSeconds}秒）`);
    updateVideoInfoUI();

    pdfTimerHandle = setInterval(async () => {
      const elapsed = Math.floor((Date.now() - pdfTimerStartedAt) / 1000);
      pdfTimerLeft = Math.max(0, pdfReadSeconds - elapsed);
      updateVideoInfoUI();
      saveCurrentProgress(false);

      if (pdfTimerLeft <= 0) {
        clearInterval(pdfTimerHandle);
        pdfTimerHandle = null;

        const current = getCurrentSelectedItem() || item;
        markCurrentCompleted({ completeReason: 'pdf_simple_wait' });
        setStatus(`PDF 停留计时完成：${current.text}`);

        if (!isAutoAdvancing) {
          await autoPlayNext('pdfTimeout');
        }
      }
    }, 1000);
  }

  async function playCurrentVideoOnly() {
    const content = getCurrentContentInfo();
    if (content.type === 'video') {
      setStatus('尝试播放当前视频...');
      const result = await tryPlayVideo();
      updateVideoInfoUI();
      setStatus(result.ok ? `成功：${result.reason}` : `失败：${result.reason}`);
      return;
    }

    if (content.type === 'pdf') {
      const item = getCurrentSelectedItem() || getCurrentPseudoItem();
      startPdfCountdown(item, content.src || '');
      setStatus(`当前为 PDF，已开始简单阅读计时 ${pdfReadSeconds} 秒`);
      return;
    }

    setStatus('当前未检测到视频/PDF内容');
  }

  function triggerAnchorOpen(a) {
    if (!a) return false;
    try {
      highlightElement(a.closest('li') || a);
      a.click();

      ['pointerdown', 'mousedown', 'pointerup', 'mouseup', 'click'].forEach(type => {
        a.dispatchEvent(new MouseEvent(type, {
          view: window,
          bubbles: true,
          cancelable: true
        }));
      });

      if (typeof a.onclick === 'function') a.onclick();
      return true;
    } catch (err) {
      console.error('触发课程点击失败:', err);
      return false;
    }
  }

  async function waitForSelectionChange(oldId, timeout = 6000) {
    const start = Date.now();
    while (Date.now() - start < timeout) {
      const current = getCurrentSelectedAnchor();
      const newId = current?.id || '';
      if (newId && newId !== oldId) {
        return { changed: true, anchor: current, id: newId };
      }
      await wait(200);
    }
    const current = getCurrentSelectedAnchor();
    return { changed: false, anchor: current, id: current?.id || '' };
  }

  async function waitForContentChange(oldVideoSrc, oldPdfSrc, timeout = 10000) {
    const start = Date.now();
    while (Date.now() - start < timeout) {
      const video = getVisibleVideo();
      const videoSrc = video?.currentSrc || video?.src || '';
      const pdf = getVisiblePdfDetail();
      const pdfSrc = pdf.src || '';

      if (videoSrc && videoSrc !== oldVideoSrc) {
        return { changed: true, type: 'video', src: videoSrc };
      }
      if (pdfSrc && pdfSrc !== oldPdfSrc) {
        return { changed: true, type: 'pdf', src: pdfSrc };
      }
      await wait(250);
    }

    const content = getCurrentContentInfo();
    return { changed: false, type: content.type, src: content.src || '' };
  }

  async function waitForVideoReady(timeout = 10000) {
    const start = Date.now();
    while (Date.now() - start < timeout) {
      const detail = getVisibleVideoDetail();
      const video = detail.video;
      if (video) {
        const src = video.currentSrc || video.src || '';
        if (src || video.readyState >= 1) {
          return { ok: true, video, doc: detail.doc };
        }
      }
      await wait(300);
    }

    const detail = getVisibleVideoDetail();
    return { ok: false, video: detail.video, doc: detail.doc };
  }

  async function openCourseAndPlay(item, options = {}) {
    if (!item?.anchor) {
      setStatus('当前项没有可点击链接');
      return false;
    }

    const { autoTriggered = false, locate = true, retry = 2 } = options;

    for (let attempt = 1; attempt <= retry; attempt++) {
      const oldVideo = getVisibleVideo();
      const oldVideoSrc = oldVideo?.currentSrc || oldVideo?.src || '';
      const oldPdfSrc = getVisiblePdfDetail().src || '';
      const oldSelectedId = getCurrentSelectedAnchor()?.id || '';

      if (locate) highlightElement(item.element);

      setStatus(`${autoTriggered ? '自动' : '手动'}打开：${item.text}（第 ${attempt}/${retry} 次）`);

      const clicked = triggerAnchorOpen(item.anchor);
      if (!clicked) continue;

      await waitForSelectionChange(oldSelectedId, 5000);
      const changed = await waitForContentChange(oldVideoSrc, oldPdfSrc, 10000);

      const currentType = changed.type || item.resourceType || getCurrentContentInfo().type;

      if (currentType === 'video') {
        const readyResult = await waitForVideoReady(10000);
        const targetVideo = readyResult.video || getVisibleVideo();
        applyPlaybackRate(targetVideo);
        await restoreProgressForCurrent(targetVideo);
        const playResult = await tryPlayVideo(targetVideo);
        updateVideoInfoUI();

        if (playResult.ok) {
          stopPdfCountdown();
          lightweightRescan(false, true);
          setStatus(`成功：${item.text} -> ${playResult.reason}`);
          return true;
        }

        await wait(700);
        continue;
      }

      if (currentType === 'pdf' || item.resourceType === 'pdf') {
        stopPdfCountdown();
        lightweightRescan(false, true);
        startPdfCountdown(item, changed.src || item.href || '');
        updateVideoInfoUI();
        setStatus(`成功：已打开 PDF -> ${item.text}，开始停留 ${pdfReadSeconds} 秒`);
        return true;
      }

      await wait(700);
    }

    setStatus(`最终失败：${item.text}`);
    return false;
  }

  function shouldTriggerNearEnd(info) {
    if (!info.exists) return false;
    if (!Number.isFinite(info.duration) || info.duration <= 0) return false;
    if (info.paused || info.ended) return false;
    const remain = info.duration - info.currentTime;
    return remain <= 0.8 && info.progress >= 98.5;
  }

  async function autoPlayNext(reason = 'ended') {
    if (!autoNextEnabled || isAutoAdvancing) return;

    const currentItem = getCurrentSelectedItem();
    if (!currentItem) return;

    const content = getCurrentContentInfo();
    const currentSrc = content.src || '';

    const token = `${reason}|${currentSrc}|${currentItem.index}|${currentItem.id || ''}`;
    if (reason === 'ended' && lastEndedToken === token) return;
    if (reason === 'nearEnd' && lastNearEndToken === token) return;
    if (reason === 'ended') lastEndedToken = token;
    if (reason === 'nearEnd') lastNearEndToken = token;

    const nextItem = getNextItemFromCurrent();
    if (!nextItem) {
      setStatus(`已播放完范围末尾或最后一项：${currentItem.text}`);
      return;
    }

    isAutoAdvancing = true;
    try {
      setStatus(`当前内容已完成，自动切换下一项：${nextItem.text}`);
      await openCourseAndPlay(nextItem, {
        autoTriggered: true,
        locate: autoLocateCurrent,
        retry: 3
      });
    } finally {
      setTimeout(() => {
        isAutoAdvancing = false;
      }, 1500);
    }
  }

  function locateCurrentSelected() {
    const a = getCurrentSelectedAnchor();
    if (!a) {
      setStatus('未找到当前选中课程');
      return;
    }
    highlightElement(a.closest('li') || a);
    setStatus(`已定位当前课程：${a.getAttribute('title') || getText(a)}`);
  }

  function copyCurrentContentUrl() {
    const content = getCurrentContentInfo();
    const src = content.src || '';
    if (!src) {
      setStatus('复制失败：当前没有内容地址');
      return;
    }

    navigator.clipboard.writeText(src).then(() => {
      setStatus('已复制当前内容地址');
    }).catch(() => {
      const ta = document.createElement('textarea');
      ta.value = src;
      document.body.appendChild(ta);
      ta.select();
      document.execCommand('copy');
      ta.remove();
      setStatus('已复制当前内容地址');
    });
  }

  function clearAllProgress() {
    if (!confirm('确定清空所有断点记录吗？')) return;
    progressStore = {};
    saveProgressStore();
    stopPdfCountdown();
    lightweightRescan(false, true);
    updateVideoInfoUI();
    setStatus('已清空所有断点记录');
  }

  function updateVideoInfoUI() {
    const infoEl = document.getElementById('__clp_video_info__');
    if (!infoEl) return;

    const content = getCurrentContentInfo();
    const currentAnchor = getCurrentSelectedAnchor();
    const currentTitle = currentAnchor?.getAttribute('title') || getText(currentAnchor) || document.title || '无';
    const currentProgress = getCurrentCourseProgress();
    const mode = getPageMode();

    if (!content.exists) {
      infoEl.innerHTML = `
        <div class="monitor-grid">
          <div><b>页面模式</b><span>${mode}</span></div>
          <div><b>当前课程</b><span>${escapeHtml(currentTitle)}</span></div>
          <div><b>内容类型</b><span>未检测到</span></div>
          <div><b>列表项数量</b><span>${courseItems.length}</span></div>
          <div><b>倍速</b><span>${playbackRate}x</span></div>
          <div><b>PDF简单阅读</b><span>${pdfSimpleEnabled ? '开启' : '关闭'}</span></div>
        </div>
      `;
      return;
    }

    if (content.type === 'pdf') {
      const elapsed = pdfTimerStartedAt ? Math.floor((Date.now() - pdfTimerStartedAt) / 1000) : 0;
      const remain = pdfTimerHandle ? Math.max(0, pdfReadSeconds - elapsed) : 0;
      const progress = pdfReadSeconds > 0 ? Math.min(100, (elapsed / pdfReadSeconds) * 100) : 0;
      const fileName = content.src ? content.src.split('/').pop() : '无';

      infoEl.innerHTML = `
        <div class="monitor-grid">
          <div><b>页面模式</b><span>${mode}</span></div>
          <div><b>当前课程</b><span>${escapeHtml(currentTitle)}</span></div>
          <div><b>内容类型</b><span>PDF</span></div>
          <div><b>阅读模式</b><span>简单停留计时</span></div>
          <div><b>计时状态</b><span>${pdfTimerHandle ? '计时中' : '未开始'}</span></div>
          <div><b>已停留</b><span>${formatTime(elapsed)}</span></div>
          <div><b>目标时长</b><span>${formatTime(pdfReadSeconds)}</span></div>
          <div><b>剩余</b><span>${formatTime(remain)}</span></div>
          <div><b>估算进度</b><span>${progress.toFixed(1)}%</span></div>
          <div><b>断点记录</b><span>${currentProgress ? formatTime(currentProgress.currentTime || 0) : '无'}</span></div>
          <div><b>自动下一项</b><span>${autoNextEnabled ? '开启' : '关闭'}</span></div>
          <div><b>PDF简单阅读</b><span>${pdfSimpleEnabled ? '开启' : '关闭'}</span></div>
        </div>
        <div class="monitor-src"><b>Src:</b> <span title="${escapeHtml(content.src)}">${escapeHtml(fileName)}</span></div>
      `;
      return;
    }

    const stateText = content.ended ? 'ended' : (content.paused ? 'paused' : 'playing');
    const remain = Number.isFinite(content.duration) ? Math.max(0, content.duration - content.currentTime) : 0;
    const fileName = content.src ? content.src.split('/').pop() : '无';

    infoEl.innerHTML = `
      <div class="monitor-grid">
        <div><b>页面模式</b><span>${mode}</span></div>
        <div><b>当前课程</b><span>${escapeHtml(currentTitle)}</span></div>
        <div><b>内容类型</b><span>视频</span></div>
        <div><b>状态</b><span>${stateText}</span></div>
        <div><b>静音</b><span>${content.muted ? '是' : '否'}</span></div>
        <div><b>倍速</b><span>${playbackRate}x</span></div>
        <div><b>进度</b><span>${content.progress.toFixed(1)}%</span></div>
        <div><b>时间</b><span>${formatTime(content.currentTime)} / ${formatTime(content.duration)}</span></div>
        <div><b>剩余</b><span>${formatTime(remain)}</span></div>
        <div><b>ReadyState</b><span>${content.readyState}</span></div>
        <div><b>断点记录</b><span>${currentProgress ? formatTime(currentProgress.currentTime || 0) : '无'}</span></div>
        <div><b>来源</b><span>${escapeHtml(content.source || 'top')}</span></div>
      </div>
      <div class="monitor-src"><b>Src:</b> <span title="${escapeHtml(content.src)}">${escapeHtml(fileName)}</span></div>
    `;
  }

  function renderEmptyPlaceholder() {
    const tbody = document.getElementById('__clp_table_body__');
    const summary = document.getElementById('__clp_summary__');
    if (!tbody || !summary) return;

    summary.innerHTML = `
      <span class="summary-left">
        <span class="summary-pill">页面模式 ${getPageMode()}</span>
        <span class="summary-pill">列表项 ${courseItems.length}</span>
        <span class="summary-pill">倍速 ${playbackRate}x</span>
      </span>
      <span id="__clp_status__">${escapeHtml(statusText)}</span>
    `;

    tbody.innerHTML = `
      <tr>
        <td colspan="6" style="padding:16px; color:#666; line-height:1.8;">
          当前未识别到可用课程列表。<br>
          仍可使用：播放当前、倍速、PDF简单停留、复制内容地址。<br>
          如仍异常，请把控制台里 [findCourseItems] 的几行日志发给我。
        </td>
      </tr>
    `;
  }

  function renderTable(items) {
    const tbody = document.getElementById('__clp_table_body__');
    const summary = document.getElementById('__clp_summary__');
    if (!tbody || !summary) return;

    if (!items.length) {
      renderEmptyPlaceholder();
      return;
    }

    const currentItem = getCurrentSelectedItem();
    const rangeText = (() => {
      const { start, end } = getRangeNormalized();
      if (!start && !end) return '全范围';
      return `${start || 1} - ${end || courseItems.length || '-'}`;
    })();

    summary.innerHTML = `
      <span class="summary-left">
        <span class="summary-pill">总数 ${courseItems.length}</span>
        <span class="summary-pill">显示 ${items.length}</span>
        <span class="summary-pill">当前 ${currentItem ? currentItem.index : '-'}/${courseItems.length || '-'}</span>
        <span class="summary-pill">范围 ${rangeText}</span>
        <span class="summary-pill">倍速 ${playbackRate}x</span>
      </span>
      <span id="__clp_status__">${escapeHtml(statusText)}</span>
    `;

    tbody.innerHTML = items.map(item => {
      const p = item.progressInfo;
      const completed = !!p?.completed;
      const inRangeFlag = inPlayRange(item);
      const typeText = item.resourceType === 'pdf' ? 'PDF' : (item.resourceType === 'video' ? '视频' : '未知');

      return `
        <tr class="row-hover ${item.active ? 'row-active' : ''}">
          <td>${item.index}</td>
          <td class="course-name-cell" data-index="${item.index}" title="双击可打开并处理">
            <div class="course-title">${escapeHtml(item.text)}</div>
            <div class="row-badge-wrap">
              ${item.active ? '<span class="tag-mini tag-active">当前播放项</span>' : ''}
              ${completed ? '<span class="tag-mini tag-done">已完成</span>' : ''}
              ${p && !completed ? `<span class="tag-mini tag-progress">断点 ${escapeHtml(formatTime(p.currentTime || 0))}</span>` : ''}
              ${inRangeFlag ? '<span class="tag-mini tag-range">范围内</span>' : ''}
              ${item.resourceType === 'pdf' ? '<span class="tag-mini tag-pdf">PDF</span>' : '<span class="tag-mini tag-video">视频</span>'}
            </div>
          </td>
          <td>${escapeHtml(item.dataId || '')}</td>
          <td>${escapeHtml(typeText)}</td>
          <td>${item.active ? '<span class="tag-mini tag-active">已选中</span>' : '<span class="tag-mini">普通</span>'}</td>
          <td>
            <div class="row-actions">
              <button class="op-btn btn-locate" data-action="locate" data-index="${item.index}">定位</button>
              <button class="op-btn btn-play" data-action="play" data-index="${item.index}">打开处理</button>
              <button class="op-btn btn-next" data-action="playnext" data-index="${item.index}">从此连播</button>
            </div>
          </td>
        </tr>
      `;
    }).join('');
  }

  function applyFilterAndRender() {
    const input = document.getElementById('__clp_search__');
    const keyword = input?.value?.trim().toLowerCase() || keywordCache || '';
    keywordCache = keyword;
    saveConfig();

    let items = [...courseItems];
    if (keyword) {
      items = items.filter(item =>
        item.text.toLowerCase().includes(keyword) ||
        item.shortText.toLowerCase().includes(keyword) ||
        String(item.dataId).toLowerCase().includes(keyword) ||
        String(item.resourceType).toLowerCase().includes(keyword)
      );
    }

    filteredItems = items;
    renderTable(items);
  }

  function lightweightRescan(render = true, force = false) {
    const now = Date.now();
    if (!force && now - lastScanAt < 1200) {
      if (!render) applyFilterAndRender();
      return;
    }

    lastScanAt = now;
    courseItems = findCourseItems();

    if (render) createPanel();
    else applyFilterAndRender();

    console.log('课程列表扫描完成:', courseItems);
  }

  function bindVideoEvents(video, docRef = document) {
    if (!video) return;
    if (currentVideoBound === video && currentBoundDoc === docRef) return;

    currentVideoBound = video;
    currentBoundDoc = docRef;

    ['play', 'pause', 'loadedmetadata', 'timeupdate', 'ratechange', 'ended'].forEach(evt => {
      video.addEventListener(evt, async () => {
        if (evt === 'loadedmetadata') {
          applyPlaybackRate(video);
          await restoreProgressForCurrent(video);
        }

        if (evt === 'timeupdate') saveCurrentProgress(false);
        if (evt === 'pause') saveCurrentProgress(true);

        if (evt === 'ended') {
          markCurrentCompleted();
          updateVideoInfoUI();
          setStatus('检测到当前视频播放完成');
          await autoPlayNext('ended');
          return;
        }

        updateVideoInfoUI();
      });
    });
  }

  function setupVideoMonitor() {
    if (monitorTimer) clearInterval(monitorTimer);

    monitorTimer = setInterval(async () => {
      const detail = getVisibleVideoDetail();
      const video = detail.video;

      if (video) {
        bindVideoEvents(video, detail.doc);
        applyPlaybackRate(video);
      }

      const videoInfo = getVideoInfo(video);
      const currentVideoSrc = videoInfo.src || '';
      const currentPdf = getVisiblePdfDetail();
      const currentPdfSrc = currentPdf.src || '';

      if (currentVideoSrc !== lastVideoSrc) {
        lastVideoSrc = currentVideoSrc;
        activeResumeToken = '';
        if (currentVideoSrc) {
          stopPdfCountdown();
          lastEndedToken = '';
          lastNearEndToken = '';
          setStatus(`视频已切换：${currentVideoSrc.split('/').pop()}`);
          await restoreProgressForCurrent(video);
        }
      }

      if (currentPdfSrc !== lastPdfSrc) {
        lastPdfSrc = currentPdfSrc;
        if (currentPdfSrc) {
          const item = getCurrentSelectedItem() || getCurrentPseudoItem();
          setStatus(`PDF 已切换：${(item?.text || '当前PDF')}`);
          if (item && (item.resourceType === 'pdf' || /pdfjs\/web\/viewer\.html|\.pdf(\?|$)/i.test(currentPdfSrc))) {
            startPdfCountdown(item, currentPdfSrc);
          }
        } else {
          stopPdfCountdown();
        }
      }

      const selected = getCurrentSelectedAnchor();
      const selectedId = selected?.id || '';

      if (selectedId !== lastSelectedId) {
        lastSelectedId = selectedId;
        lightweightRescan(false, true);

        if (selected) {
          const title = selected.getAttribute('title') || getText(selected);
          setStatus(`当前课程已切换：${title}`);

          if (autoLocateCurrent) {
            highlightElement(selected.closest('li') || selected);
          }
        }

        const currentItem = getCurrentSelectedItem();
        if (currentItem?.resourceType !== 'pdf' && !currentPdfSrc) {
          stopPdfCountdown();
        }
      }

      if (shouldTriggerNearEnd(videoInfo)) {
        markCurrentCompleted();
        await autoPlayNext('nearEnd');
      }

      updateVideoInfoUI();
    }, 1500);
  }

  function setupSelectionObserver() {
    if (selectionObserver) selectionObserver.disconnect();

    const root = getVideoRootLi() || document.body;
    if (!root) return;

    let timer = null;
    selectionObserver = new MutationObserver(() => {
      clearTimeout(timer);
      timer = setTimeout(() => {
        const currentId = getCurrentSelectedAnchor()?.id || '';
        if (currentId && currentId !== lastSelectedId) {
          lastSelectedId = currentId;
          lightweightRescan(false, true);
        }
      }, 600);
    });

    selectionObserver.observe(root, {
      subtree: true,
      attributes: true,
      attributeFilter: ['class']
    });
  }

  function exportJson() {
    const data = {
      pageMode: getPageMode(),
      pageUrl: location.href,
      title: document.title,
      courseItems: courseItems.map(item => ({
        index: item.index,
        text: item.text,
        id: item.id,
        dataId: item.dataId,
        onclick: item.onclick,
        href: item.href,
        visible: item.visible,
        active: item.active,
        score: item.score,
        resourceType: item.resourceType,
        progressInfo: item.progressInfo || null
      })),
      currentContent: getCurrentContentInfo(),
      progressStore
    };

    const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'video-course-list-v270.json';
    a.click();
    URL.revokeObjectURL(url);
  }

  function bindDragEvents() {
    const panel = document.getElementById(PANEL_ID);
    const header = document.getElementById('__clp_drag_handle__');
    if (!panel || !header) return;

    header.addEventListener('mousedown', (e) => {
      const avoid = e.target.closest('button, input, select, label');
      if (avoid) return;

      const rect = panel.getBoundingClientRect();
      dragState.dragging = true;
      dragState.startX = e.clientX;
      dragState.startY = e.clientY;
      dragState.startLeft = rect.left;
      dragState.startTop = rect.top;

      panel.style.left = rect.left + 'px';
      panel.style.top = rect.top + 'px';
      panel.style.right = 'auto';
      panel.style.bottom = 'auto';

      document.body.style.userSelect = 'none';
    });

    document.addEventListener('mousemove', (e) => {
      if (!dragState.dragging) return;

      const rect = panel.getBoundingClientRect();
      const width = rect.width;
      const height = rect.height;

      let left = dragState.startLeft + (e.clientX - dragState.startX);
      let top = dragState.startTop + (e.clientY - dragState.startY);

      left = clamp(left, 0, window.innerWidth - Math.min(width, window.innerWidth));
      top = clamp(top, 0, window.innerHeight - Math.min(height, window.innerHeight));

      panel.style.left = left + 'px';
      panel.style.top = top + 'px';
    });

    document.addEventListener('mouseup', () => {
      dragState.dragging = false;
      document.body.style.userSelect = '';
    });
  }

  function applyPanelCollapsedUI() {
    const panel = document.getElementById(PANEL_ID);
    const content = document.getElementById('__clp_content__');
    const toggleBtn = document.getElementById('__clp_toggle__');
    if (!panel || !content || !toggleBtn) return;

    if (panelCollapsed) {
      panel.classList.add('panel-collapsed');
      content.style.display = 'none';
      toggleBtn.textContent = '展开';
    } else {
      panel.classList.remove('panel-collapsed');
      content.style.display = 'flex';
      toggleBtn.textContent = '收起';
    }

    saveConfig();
  }

  function injectStyle() {
    const style = document.createElement('style');
    style.textContent = `
      #${PANEL_ID} {
        position: fixed;
        top: 20px;
        right: 20px;
        width: 980px;
        min-width: 760px;
        max-width: calc(100vw - 20px);
        height: 84vh;
        min-height: 480px;
        max-height: 90vh;
        background: #fff;
        border: 1px solid #dcdfe6;
        border-radius: 16px;
        box-shadow: 0 16px 42px rgba(0,0,0,0.18);
        z-index: 999999;
        font-family: Arial, sans-serif;
        overflow: hidden;
        resize: both;
        display: flex;
        flex-direction: column;
      }

      #${PANEL_ID}.panel-collapsed {
        width: 260px !important;
        min-width: 260px !important;
        max-width: 260px !important;
        height: 56px !important;
        min-height: 56px !important;
        max-height: 56px !important;
        resize: none !important;
        overflow: hidden !important;
      }

      #${PANEL_ID} .panel-header {
        background: linear-gradient(135deg, #2f80ed, #56ccf2);
        color: #fff;
        padding: 12px 14px;
        font-size: 16px;
        font-weight: bold;
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: 12px;
        cursor: move;
        flex-shrink: 0;
        height: 56px;
        box-sizing: border-box;
      }

      #${PANEL_ID} .panel-title {
        display: flex;
        align-items: center;
        gap: 10px;
        min-width: 0;
      }

      #${PANEL_ID} .panel-subtitle {
        font-size: 12px;
        opacity: 0.9;
        font-weight: normal;
      }

      #${PANEL_ID}.panel-collapsed .panel-subtitle,
      #${PANEL_ID}.panel-collapsed #__clp_refresh__,
      #${PANEL_ID}.panel-collapsed #__clp_export__ {
        display: none;
      }

      #${PANEL_ID} .panel-actions {
        display: flex;
        gap: 8px;
      }

      #${PANEL_ID} .panel-btn {
        background: rgba(255,255,255,0.18);
        color: #fff;
        border: none;
        border-radius: 8px;
        padding: 6px 10px;
        cursor: pointer;
        font-size: 12px;
      }

      #${PANEL_ID} .panel-content {
        display: flex;
        flex-direction: column;
        min-height: 0;
        flex: 1;
      }

      #${PANEL_ID} .panel-toolbar {
        padding: 10px 12px;
        background: #f7f9fc;
        border-bottom: 1px solid #ebeef5;
        display: flex;
        gap: 8px;
        flex-wrap: wrap;
        align-items: center;
      }

      #${PANEL_ID} .toolbar-left,
      #${PANEL_ID} .toolbar-right {
        display: flex;
        gap: 8px;
        flex-wrap: wrap;
        align-items: center;
      }

      #${PANEL_ID} .toolbar-left {
        flex: 1 1 320px;
        min-width: 240px;
      }

      #${PANEL_ID} .toolbar-right {
        flex: 999 1 auto;
      }

      #${PANEL_ID} input,
      #${PANEL_ID} select {
        box-sizing: border-box;
        padding: 9px 12px;
        border: 1px solid #dcdfe6;
        border-radius: 10px;
        outline: none;
        font-size: 13px;
        background: #fff;
      }

      #${PANEL_ID} input[type="text"] {
        flex: 1;
        min-width: 180px;
      }

      #${PANEL_ID} .tool-btn {
        border: none;
        border-radius: 10px;
        padding: 8px 12px;
        cursor: pointer;
        font-size: 12px;
        background: #ecf5ff;
        color: #409eff;
        white-space: nowrap;
        min-width: 88px;
      }

      #${PANEL_ID} .btn-warn {
        background: #fdf6ec;
        color: #e6a23c;
      }

      #${PANEL_ID} .btn-green {
        background: #e8f5e9;
        color: #2e7d32;
      }

      #${PANEL_ID} .btn-danger {
        background: #fdecea;
        color: #d93025;
      }

      #${PANEL_ID} .panel-options {
        padding: 8px 12px;
        background: #fafbfd;
        border-bottom: 1px solid #ebeef5;
        display: flex;
        gap: 16px;
        flex-wrap: wrap;
        font-size: 12px;
      }

      #${PANEL_ID} .panel-options label {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        white-space: nowrap;
      }

      #${PANEL_ID} .range-wrap {
        display: flex;
        gap: 6px;
        align-items: center;
        flex-wrap: wrap;
      }

      #${PANEL_ID} .range-wrap input {
        width: 88px;
      }

      #${PANEL_ID} .panel-summary {
        padding: 8px 12px;
        font-size: 13px;
        color: #666;
        background: #fcfcfc;
        border-bottom: 1px solid #ebeef5;
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: 8px;
        flex-wrap: wrap;
      }

      #${PANEL_ID} .summary-left {
        display: flex;
        gap: 8px;
        flex-wrap: wrap;
      }

      #${PANEL_ID} .summary-pill {
        padding: 4px 8px;
        background: #f4f7fb;
        border: 1px solid #e7edf5;
        border-radius: 999px;
        color: #5a6472;
        font-size: 12px;
      }

      #${PANEL_ID} .panel-monitor {
        padding: 10px 12px;
        background: #fcfcfc;
        border-bottom: 1px solid #ebeef5;
        font-size: 12px;
        color: #444;
      }

      #${PANEL_ID} .monitor-grid {
        display: grid;
        grid-template-columns: repeat(6, minmax(100px, 1fr));
        gap: 8px 12px;
      }

      #${PANEL_ID} .monitor-grid > div {
        display: flex;
        flex-direction: column;
        min-width: 0;
      }

      #${PANEL_ID} .monitor-grid b {
        color: #657286;
        font-size: 11px;
        margin-bottom: 2px;
      }

      #${PANEL_ID} .monitor-grid span,
      #${PANEL_ID} .monitor-src {
        word-break: break-all;
      }

      #${PANEL_ID} .panel-body {
        flex: 1;
        min-height: 0;
        overflow: auto;
        background: #fff;
      }

      #${PANEL_ID} table {
        width: 100%;
        border-collapse: collapse;
        table-layout: fixed;
      }

      #${PANEL_ID} th, #${PANEL_ID} td {
        border-bottom: 1px solid #f0f0f0;
        padding: 9px 8px;
        font-size: 12px;
        text-align: left;
        vertical-align: top;
        word-break: break-all;
      }

      #${PANEL_ID} th {
        background: #f8f9fb;
        position: sticky;
        top: 0;
        z-index: 2;
      }

      #${PANEL_ID} .course-title {
        font-size: 13px;
        color: #333;
        line-height: 1.45;
      }

      #${PANEL_ID} .row-badge-wrap {
        margin-top: 6px;
        display: flex;
        flex-wrap: wrap;
        gap: 6px;
      }

      #${PANEL_ID} .tag-mini {
        display: inline-block;
        padding: 2px 8px;
        border-radius: 999px;
        background: #ecf5ff;
        color: #409eff;
        font-size: 11px;
        line-height: 1.6;
      }

      #${PANEL_ID} .tag-active {
        background: #fff3e0;
        color: #e67e22;
      }

      #${PANEL_ID} .tag-done {
        background: #e8f5e9;
        color: #2e7d32;
      }

      #${PANEL_ID} .tag-progress {
        background: #ede7f6;
        color: #6a1b9a;
      }

      #${PANEL_ID} .tag-range {
        background: #e3f2fd;
        color: #1565c0;
      }

      #${PANEL_ID} .tag-pdf {
        background: #fdecea;
        color: #d93025;
      }

      #${PANEL_ID} .tag-video {
        background: #e8f5e9;
        color: #2e7d32;
      }

      #${PANEL_ID} .row-actions {
        display: flex;
        gap: 6px;
        flex-wrap: wrap;
      }

      #${PANEL_ID} .op-btn {
        border: none;
        border-radius: 8px;
        padding: 6px 10px;
        cursor: pointer;
        font-size: 12px;
        min-width: 74px;
      }

      #${PANEL_ID} .btn-locate {
        background: #e8f5e9;
        color: #2e7d32;
      }

      #${PANEL_ID} .btn-play {
        background: #ecf5ff;
        color: #409eff;
      }

      #${PANEL_ID} .btn-next {
        background: #fff3e0;
        color: #ef6c00;
      }

      #${PANEL_ID} .row-hover:hover {
        background: #f9fbff;
      }

      #${PANEL_ID} .row-active {
        background: #fffaf2;
      }

      #${PANEL_ID} .course-name-cell {
        cursor: pointer;
      }

      #__clp_status__ {
        color: #e6a23c;
        font-weight: 600;
        word-break: break-all;
      }

      .${HIGHLIGHT_CLASS} {
        outline: 3px solid #ff4d4f !important;
        background-color: rgba(255, 235, 59, 0.20) !important;
      }

      @media (max-width: 1200px) {
        #${PANEL_ID} {
          width: calc(100vw - 24px);
          min-width: 320px;
          left: 12px !important;
          right: 12px !important;
          top: 12px !important;
          height: 88vh;
        }

        #${PANEL_ID} .monitor-grid {
          grid-template-columns: repeat(2, minmax(120px, 1fr));
        }
      }
    `;
    document.head.appendChild(style);
  }

  function createPanel() {
    const old = document.getElementById(PANEL_ID);
    const oldRect = old?.getBoundingClientRect();
    if (old) old.remove();

    const panel = document.createElement('div');
    panel.id = PANEL_ID;
    panel.innerHTML = `
      <div class="panel-header" id="__clp_drag_handle__">
        <div class="panel-title">
          <span>助学课程列表</span>
          <span class="panel-subtitle">反馈意见表1077472126 仅供学习，不得用于其它途径</span>
        </div>
        <div class="panel-actions">
          <button class="panel-btn" id="__clp_refresh__">刷新</button>
          <button class="panel-btn" id="__clp_export__">导出JSON</button>
          <button class="panel-btn" id="__clp_toggle__">${panelCollapsed ? '展开' : '收起'}</button>
        </div>
      </div>

      <div class="panel-content" id="__clp_content__">
        <div class="panel-toolbar">
          <div class="toolbar-left">
            <input id="__clp_search__" type="text" placeholder="搜索课程标题 / 类型 / data-id..." value="${escapeHtml(keywordCache)}" />
            <select id="__clp_rate__">
              <option value="0.5">0.5x</option>
              <option value="1">1x</option>
              <option value="1.25">1.25x</option>
              <option value="1.5">1.5x</option>
              <option value="2">2x</option>
            </select>
            <select id="__clp_pdf_seconds__">
              <option value="10">PDF 10秒</option>
              <option value="20">PDF 20秒</option>
              <option value="30">PDF 30秒</option>
              <option value="45">PDF 45秒</option>
              <option value="60">PDF 60秒</option>
              <option value="90">PDF 90秒</option>
            </select>
          </div>
          <div class="toolbar-right">
            <button class="tool-btn" id="__clp_locate_current__" data-catalog-only="1">定位当前</button>
            <button class="tool-btn" id="__clp_play_current__">处理当前</button>
            <button class="tool-btn btn-green" id="__clp_next__" data-catalog-only="1">下一项</button>
            <button class="tool-btn btn-warn" id="__clp_copy_video__">复制内容地址</button>
            <button class="tool-btn btn-danger" id="__clp_clear_progress__">清空记录</button>
          </div>
        </div>

        <div class="panel-options">
          <label data-catalog-only="1"><input type="checkbox" id="__clp_auto_next__" ${autoNextEnabled ? 'checked' : ''}> 完成后自动下一项</label>
          <label data-catalog-only="1"><input type="checkbox" id="__clp_auto_locate__" ${autoLocateCurrent ? 'checked' : ''}> 自动跟踪并定位当前项</label>
          <label><input type="checkbox" id="__clp_resume_enabled__" ${resumeEnabled ? 'checked' : ''}> 视频自动恢复断点</label>
          <label><input type="checkbox" id="__clp_pdf_simple__" ${pdfSimpleEnabled ? 'checked' : ''}> 启用PDF简单自动阅读</label>
          <div class="range-wrap" data-catalog-only="1">
            <span>范围：</span>
            <input id="__clp_range_start__" type="number" min="1" placeholder="开始序号" value="${escapeHtml(rangeStart)}" />
            <span>-</span>
            <input id="__clp_range_end__" type="number" min="1" placeholder="结束序号" value="${escapeHtml(rangeEnd)}" />
            <button class="tool-btn" id="__clp_apply_range__">应用范围</button>
          </div>
        </div>

        <div class="panel-summary" id="__clp_summary__">
          <span>加载中...</span>
          <span id="__clp_status__">${escapeHtml(statusText)}</span>
        </div>

        <div class="panel-monitor" id="__clp_video_info__">
          <div>内容信息: 加载中...</div>
        </div>

        <div class="panel-body">
          <table>
            <thead>
              <tr>
                <th style="width: 54px;">序号</th>
                <th>课程标题</th>
                <th style="width: 96px;">data-id</th>
                <th style="width: 72px;">类型</th>
                <th style="width: 84px;">状态</th>
                <th style="width: 210px;">操作</th>
              </tr>
            </thead>
            <tbody id="__clp_table_body__"></tbody>
          </table>
        </div>
      </div>
    `;

    document.body.appendChild(panel);

    if (oldRect) {
      panel.style.left = oldRect.left + 'px';
      panel.style.top = oldRect.top + 'px';
      panel.style.right = 'auto';
      panel.style.bottom = 'auto';
    }

    bindPanelEvents();
    bindDragEvents();
    updateOptionUI();
    applyFilterAndRender();
    updateVideoInfoUI();
    applyPanelCollapsedUI();
  }

  function bindPanelEvents() {
    document.getElementById('__clp_refresh__')?.addEventListener('click', async () => {
      lightweightRescan(true, true);
      const detail = await waitForAnyVideo(4000);
      if (detail.video) {
        bindVideoEvents(detail.video, detail.doc);
        applyPlaybackRate(detail.video);
      }
      updateVideoInfoUI();
      setStatus('已刷新');
    });

    document.getElementById('__clp_export__')?.addEventListener('click', exportJson);

    document.getElementById('__clp_toggle__')?.addEventListener('click', () => {
      panelCollapsed = !panelCollapsed;
      applyPanelCollapsedUI();
      setStatus(panelCollapsed ? '面板已整体收起' : '面板已展开');
    });

    document.getElementById('__clp_search__')?.addEventListener('input', (e) => {
      keywordCache = e.target.value.trim().toLowerCase();
      saveConfig();
      applyFilterAndRender();
    });

    document.getElementById('__clp_rate__')?.addEventListener('change', (e) => {
      playbackRate = Number(e.target.value || 1);
      applyPlaybackRate();
      saveConfig();
      updateVideoInfoUI();
      setStatus(`已设置倍速：${playbackRate}x`);
    });

    document.getElementById('__clp_pdf_seconds__')?.addEventListener('change', (e) => {
      pdfReadSeconds = Number(e.target.value || 30);
      saveConfig();
      stopPdfCountdown();
      const content = getCurrentContentInfo();
      const item = getCurrentSelectedItem();
      if (content.type === 'pdf' && item && pdfSimpleEnabled) {
        startPdfCountdown(item, content.src || '');
      }
      updateVideoInfoUI();
      setStatus(`已设置 PDF 停留时长：${pdfReadSeconds} 秒`);
    });

    document.getElementById('__clp_locate_current__')?.addEventListener('click', locateCurrentSelected);
    document.getElementById('__clp_play_current__')?.addEventListener('click', playCurrentVideoOnly);

    document.getElementById('__clp_next__')?.addEventListener('click', async () => {
      const nextItem = getNextItemFromCurrent();
      if (!nextItem) {
        setStatus('没有下一项可处理（可能超出范围或未识别当前项）');
        return;
      }
      await openCourseAndPlay(nextItem, { autoTriggered: false, locate: true, retry: 3 });
    });

    document.getElementById('__clp_copy_video__')?.addEventListener('click', copyCurrentContentUrl);
    document.getElementById('__clp_clear_progress__')?.addEventListener('click', clearAllProgress);

    document.getElementById('__clp_apply_range__')?.addEventListener('click', () => {
      rangeStart = document.getElementById('__clp_range_start__')?.value?.trim() || '';
      rangeEnd = document.getElementById('__clp_range_end__')?.value?.trim() || '';
      saveConfig();
      lightweightRescan(false, true);
      setStatus(`已应用范围：${rangeStart || '起始'} - ${rangeEnd || '末尾'}`);
    });

    document.getElementById('__clp_auto_next__')?.addEventListener('change', (e) => {
      autoNextEnabled = !!e.target.checked;
      saveConfig();
      setStatus(autoNextEnabled ? '已开启自动下一项' : '已关闭自动下一项');
    });

    document.getElementById('__clp_auto_locate__')?.addEventListener('change', (e) => {
      autoLocateCurrent = !!e.target.checked;
      saveConfig();
      setStatus(autoLocateCurrent ? '已开启当前项跟踪定位' : '已关闭当前项跟踪定位');
    });

    document.getElementById('__clp_resume_enabled__')?.addEventListener('change', (e) => {
      resumeEnabled = !!e.target.checked;
      saveConfig();
      setStatus(resumeEnabled ? '已开启视频断点恢复' : '已关闭视频断点恢复');
    });

    document.getElementById('__clp_pdf_simple__')?.addEventListener('change', (e) => {
      pdfSimpleEnabled = !!e.target.checked;
      saveConfig();

      const content = getCurrentContentInfo();
      const item = getCurrentSelectedItem();

      if (!pdfSimpleEnabled) {
        stopPdfCountdown();
      } else if (content.type === 'pdf' && item) {
        startPdfCountdown(item, content.src || '');
      }

      updateVideoInfoUI();
      setStatus(pdfSimpleEnabled ? '已开启 PDF 简单自动阅读' : '已关闭 PDF 简单自动阅读');
    });

    document.getElementById(PANEL_ID)?.addEventListener('click', async (e) => {
      const btn = e.target.closest('button[data-action]');
      if (!btn) return;

      const action = btn.dataset.action;
      const index = Number(btn.dataset.index);
      const item = findItemByIndex(index);
      if (!item) return;

      if (action === 'locate') {
        highlightElement(item.element);
        setStatus(`已定位：${item.text}`);
      }

      if (action === 'play') {
        await openCourseAndPlay(item, { autoTriggered: false, locate: true, retry: 3 });
      }

      if (action === 'playnext') {
        rangeStart = String(item.index);
        autoNextEnabled = true;
        saveConfig();
        updateOptionUI();
        const ok = await openCourseAndPlay(item, { autoTriggered: false, locate: true, retry: 3 });
        if (ok) {
          lightweightRescan(false, true);
          setStatus(`已从该项开始处理，后续按范围自动连播：${item.text}`);
        }
      }
    });

    document.getElementById(PANEL_ID)?.addEventListener('dblclick', async (e) => {
      const cell = e.target.closest('.course-name-cell');
      if (!cell) return;
      const index = Number(cell.dataset.index);
      const item = findItemByIndex(index);
      if (!item) return;
      await openCourseAndPlay(item, { autoTriggered: false, locate: true, retry: 3 });
    });
  }

  async function init() {
    loadConfig();
    loadProgressStore();
    injectStyle();
    lightweightRescan(true, true);

    setTimeout(() => lightweightRescan(true, true), 1500);
    setTimeout(() => lightweightRescan(true, true), 3500);
    setTimeout(() => lightweightRescan(true, true), 6000);

    updateVideoInfoUI();
    setupVideoMonitor();
    setupSelectionObserver();

    const selected = getCurrentSelectedAnchor();
    lastSelectedId = selected?.id || '';
    lastVideoSrc = getVideoInfo().src || '';
    lastPdfSrc = getVisiblePdfDetail().src || '';

    setStatus(`页面模式：${getPageMode()}`);

    const detail = await waitForAnyVideo(12000);
    if (detail.video) {
      bindVideoEvents(detail.video, detail.doc);
      applyPlaybackRate(detail.video);
      updateVideoInfoUI();
      setStatus(`已检测到视频：${detail.frame ? 'iframe' : 'top'} / ${detail.source}`);
    } else {
      const pdf = getVisiblePdfDetail();
      if (pdf.element) {
        const item = getCurrentSelectedItem() || getCurrentPseudoItem();
        if (item && pdfSimpleEnabled) startPdfCountdown(item, pdf.src || '');
        setStatus(`已检测到 PDF，简单阅读模式 ${pdfSimpleEnabled ? '开启' : '关闭'}`);
      } else {
        setStatus(`未检测到内容，列表项：${courseItems.length}`);
      }
    }
  }

  window.addEventListener('beforeunload', () => {
    saveCurrentProgress(true);
    saveConfig();
  });

  window.addEventListener('load', () => {
    setTimeout(init, 2000);
  });
})();