/* ===== 布局与样式 ===== */
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: #f4f5f7;
      display: flex; justify-content: center; align-items: flex-start;
      margin: 0; padding: 20px;
      transition:
        padding-left 0.4s cubic-bezier(0.25, 0.8, 0.25, 1),
        padding-right 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
      height: 100vh; box-sizing: border-box; overflow: hidden;
    }
    body.sidebar-is-open { padding-left: 340px; }
    body.ai-sidebar-is-open { padding-right: 340px; }

    .main-content {
      display: flex; flex-direction: column;
      width: 80vw; max-width: 1600px;
      height: calc(100vh - 40px); max-height: 900px;
      transition: width 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    }

    .experiment-condition-bar {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      align-self: flex-start;
      margin: 0 0 10px;
      padding: 4px;
      border: 1px solid #d6dbe8;
      border-radius: 8px;
      background: #fff;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
      flex-shrink: 0;
    }
    .experiment-condition-btn {
      min-width: 42px;
      height: 30px;
      padding: 0 10px;
      border-radius: 6px;
      border: 1px solid transparent;
      background: #f7f8fb;
      color: #333;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0;
      cursor: pointer;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.1s ease;
    }
    .experiment-condition-btn:hover {
      background: #eef2ff;
      border-color: #bcd0ff;
    }
    .experiment-condition-btn.is-active {
      background: #e6eeff;
      border-color: #5a7ff0;
      color: #2f4aa6;
    }
    .experiment-condition-btn:active {
      transform: translateY(1px);
    }
    .experiment-condition-btn:focus-visible {
      outline: 2px solid #5a7ff0;
      outline-offset: 2px;
    }

    /* ===== 视频列表侧栏 ===== */
    .video-shelf {
      position: fixed;
      display: flex;
      flex-direction: column;
      gap: 10px;
      padding: 10px 12px;
      background-color: #fff;
      border: 1px solid #ddd;
      border-radius: 8px;
      box-shadow: 0 6px 18px rgba(0, 0, 0, 0.08);
      z-index: 400;
      width: 200px;
    }
    .video-shelf.is-hidden { display: none; }
    .video-shelf-header {
      display: flex;
      align-items: baseline;
      justify-content: space-between;
      gap: 8px;
    }
    .video-shelf-title {
      font-size: 14px;
      font-weight: 700;
      color: #111;
    }
    .video-shelf-count {
      font-size: 12px;
      color: #6b7280;
    }
    .video-shelf-list {
      display: flex;
      flex-direction: column;
      gap: 10px;
      overflow-y: auto;
      padding-right: 2px;
      max-height: none;
    }
    .video-shelf-empty {
      font-size: 12px;
      color: #6b7280;
      text-align: center;
      padding: 10px 0;
    }
    .video-shelf-card {
      border: 1px solid #e5e7eb;
      border-radius: 8px;
      padding: 8px;
      background: #f9fafb;
      display: flex;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
    }
    .video-shelf-card:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 12px rgba(15, 23, 42, 0.12);
      border-color: #c7d2fe;
    }
    .video-shelf-card.is-active {
      border-color: #3b82f6;
      box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.18);
      background: #eef2ff;
    }
    .video-shelf-thumb {
      width: 100%;
      aspect-ratio: 16 / 9;
      object-fit: cover;
      border-radius: 6px;
      background: #111;
      pointer-events: none;
    }
    .video-shelf-name {
      font-size: 12px;
      color: #1f2937;
      line-height: 1.4;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .danmaku-container {
      position: relative; width: 100%;
      border: 1px solid #ccc; background-color: #000;
      overflow: hidden; border-radius: 6px;
      flex: 1; min-height: 0;
    }

    /* 容器全屏 */
    .danmaku-container:fullscreen,
    .danmaku-container:-webkit-full-screen {
      width: 100vw !important; height: 100vh !important;
      max-width: none !important; max-height: none !important;
      border-radius: 0 !important; border: none !important;
    }
    /* 伪全屏（降级） */
    .danmaku-container.pseudo-fullscreen {
      position: fixed !important; inset: 0 !important;
      width: 100vw !important; height: 100vh !important;
      z-index: 9999 !important; border-radius: 0 !important; border: none !important;
      background: #000;
    }

    #my-video {
      width: 100%; height: 100%; display: block;
      object-fit: contain; background: #000;
      filter: none;
      cursor: pointer;
    }
    body.screenshot-mode #my-video {
      filter: brightness(0.78);
    }

    /* 隐藏原生控件 */
    #my-video::-webkit-media-controls-fullscreen-button,
    #my-video::-webkit-media-controls-mute-button,
    #my-video::-webkit-media-controls-volume-slider,
    #my-video::-webkit-media-controls-download-button,
    #my-video::-webkit-media-controls-picture-in-picture-button,
    #my-video::-webkit-media-controls-playback-rate-button,
    #my-video::-webkit-media-controls-toggle-closed-captions-button { display: none !important; }

    .danmaku-screen {
      position: absolute; top: 0; left: 0; width: 100%; height: 100%;
      pointer-events: none; z-index: 5;
    }
    .danmaku-item {
      position: absolute; left: 100%;
      white-space: nowrap; font-size: 24px; font-weight: bold; color: #fff;
      text-shadow: 1px 1px 2px #000; will-change: transform;
      border-radius: 4px; padding: 3px 8px;
      display: flex;
      align-items: center;
      pointer-events: auto;
      cursor: default;
    }
    .danmaku-item.is-waiting-launch {
      visibility: hidden;
      pointer-events: none;
    }

    /* ===== 对话弹幕设计 ===== */
    .danmaku-item.is-dialogue-member {
      background-color: rgba(30, 30, 30, 0.5); border: 1px solid var(--dialogue-color, #888);
      border-left-width: 4px; padding: 3px 10px 3px 8px;
      font-size: 22px; border-radius: 6px;
      transition: background-color 0.3s, transform 0.3s;
    }
    .danmaku-item.is-parent-danmaku {
      cursor: pointer; pointer-events: auto; font-weight: bold;
      background-color: color-mix(in srgb, var(--dialogue-color, #FFD700) 80%, transparent);
      text-shadow: none; border-color: rgba(255, 255, 255, 0.7);
    }
    .danmaku-item.is-parent-danmaku .danmaku-text {
      text-shadow: 1px 1px 2px #000;
    }
    .danmaku-item.is-parent-danmaku:hover {
      transform: scale(1.05); box-shadow: 0 0 10px var(--dialogue-color, #FFD700);
      z-index: 1;
    }
    .danmaku-item.is-dialogue-member:not(.is-parent-danmaku) { opacity: 0.9; }

    .danmaku-badge {
      position: absolute;
      top: -10px;
      right: -10px;
      transform: none;
      background-color: var(--dialogue-color, #ff8c00);
      color: #111;
      font-size: 14px;
      font-weight: bold;
      padding: 1px 6px;
      border-radius: 10px;
      border: 1px solid rgba(255, 255, 255, 0.7);
      line-height: 1.2;
      z-index: 1;
    }
    .danmaku-badge.simple-reply-badge {
      top: 50%;
      right: -40px;
      transform: translateY(-50%);
    }
    .danmaku-badge.inline-badge {
      position: static;
      top: auto;
      right: auto;
      transform: none;
      margin-left: 6px;
      display: inline-flex;
      align-items: center;
    }
    .danmaku-item.is-cluster-node {
      background-color: color-mix(in srgb, var(--dialogue-color, #ff8c00) 40%, transparent);
    }
    .dialogue-card .cluster-node {
      border: 1px solid rgba(120, 160, 255, 0.4);
      border-radius: 6px;
      padding: 6px 10px;
      margin: 6px 0;
      background-color: rgba(120, 160, 255, 0.08);
    }
    .message-list ul { list-style: none; padding: 0; margin: 0; }
    .message-list > ul > li { border-top: 1px solid #eee; }
    .message-list > ul > li:first-child { border-top: none; }

    .dialogue-message-item {
      padding: 8px 5px;
      font-size: 13px;
      cursor: pointer;
      transition: background-color 0.2s;
    }
    .dialogue-message-item:hover { background-color: #e9ecef; }

    .cluster-node > .dialogue-message-content {
      background-color: rgba(120, 160, 255, 0.08);
      border-radius: 4px;
      padding: 6px 8px;
      border: 1px solid rgba(120, 160, 255, 0.2);
    }

    .dialogue-message-content {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .message-text { flex: 1; }

    .cluster-expand-toggle {
      width: 16px; height: 16px;
      border-radius: 50%;
      border: 1px solid #3a6ff7;
      color: #3a6ff7;
      display: inline-flex; align-items: center; justify-content: center;
      font-size: 12px; font-weight: bold;
      flex-shrink: 0;
    }
    .cluster-node.collapsed .cluster-expand-toggle::before { content: '+'; }
    .cluster-node:not(.collapsed) .cluster-expand-toggle::before { content: '-'; }

    .cluster-count {
      font-size: 12px;
      color: #fff;
      background-color: #ffb347;
      padding: 1px 6px;
      border-radius: 8px;
      font-weight: 500;
    }
    .semantic-inline-count {
      background-color: #facc15;
      color: #111;
      margin-left: auto;
    }
    .tail-inline-count {
      background-color: #94a3b8;
      color: #fff;
    }

    .cluster-replies {
      list-style: none;
      margin: 6px 0 0 0;
      padding-left: 24px;
      border-left: 2px solid rgba(120, 160, 255, 0.2);
      margin-left: 12px;
      display: flex; flex-direction: column; gap: 4px;
    }
    .cluster-node.collapsed .cluster-replies { display: none; }
    .cluster-replies li {
      display: flex; gap: 6px;
      padding: 6px 5px;
      cursor: pointer;
      border-radius: 4px;
      transition: background-color 0.2s;
    }
    .cluster-replies li:hover { background-color: rgba(58, 111, 247, 0.08); }
    .danmaku-flood-count {
      margin-left: 6px;
      font-style: italic;
      font-weight: 700;
      color: #ffd166;
      text-shadow: 0 0 6px rgba(255, 209, 102, 0.8), 0 0 12px rgba(255, 255, 255, 0.6);
      letter-spacing: 1px;
    }

    /* ===== 对话弹幕连接线样式 ===== */
    .dialogue-connector-svg {
      position: absolute; top: 0; left: 0; width: 100%; height: 100%;
      pointer-events: none; z-index: 4;
      overflow: visible;
    }
    .dialogue-connector-line {
      stroke: var(--dialogue-color, #ccc);
      stroke-width: 2;
      stroke-linecap: round;
      filter: none;
      transition: opacity 0.3s;
    }
    body.screenshot-mode .dialogue-connector-line {
      stroke-width: 2.8;
      filter: drop-shadow(0 0 2px rgba(0, 0, 0, 0.75)) drop-shadow(0 0 6px rgba(0, 0, 0, 0.45));
    }
    
    /* ===== 弹幕交互样式 (赞/踩) ===== */
    .danmaku-reaction-icon {
      width: 20px;
      height: 20px;
      margin-left: 8px;
      flex-shrink: 0;
      vertical-align: middle;
    }

    .danmaku-interaction-menu {
      position: absolute;
      display: flex;
      gap: 10px;
      background-color: rgba(40, 40, 40, 0.9);
      padding: 5px 10px;
      border-radius: 20px;
      border: 1px solid #666;
      z-index: 10;
      transform: translate(-50%, -110%);
      user-select: none;
      pointer-events: auto;
    }

    .danmaku-interaction-icon {
      width: 28px;
      height: 28px;
      cursor: pointer;
      transition: transform 0.15s ease-out;
    }
    
    .danmaku-interaction-icon:hover {
      transform: scale(1.2);
    }
    
    /* ========================================= */

    @keyframes danmaku-scroll {
      from { transform: translateX(0); }
      to   { transform: translateX(var(--scroll-to-x, -110vw)); }
    }
    .danmaku-screen.paused .danmaku-item { animation-play-state: paused; }

    .danmaku-controls {
      width: 100%; margin: 10px 0; display: flex; box-sizing: border-box; flex-shrink: 0; align-items: center;
    }
    .danmaku-controls-inner {
      width: 100%;
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 10px;
      border: 1px solid #e2e2e2;
      border-radius: 8px;
      background: #fafafa;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
      box-sizing: border-box;
    }
    .danmaku-left-tools {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-shrink: 0;
      position: relative;
    }
    .danmaku-count-box {
      font-size: 12px;
      color: #666;
      padding: 4px 8px;
      border-radius: 6px;
      background: #f0f0f0;
      border: 1px solid #e0e0e0;
      white-space: nowrap;
    }
    .danmaku-tool-btn {
      width: 36px;
      height: 36px;
      border-radius: 6px;
      border: 1px solid #d7d7d7;
      background: #fff;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      padding: 0;
      transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.1s ease;
    }
    .danmaku-tool-btn:hover {
      background: #f3f6ff;
      border-color: #bcd0ff;
    }
    .danmaku-tool-btn.is-active {
      border-color: #5a7ff0;
      background-color: #eef2ff;
    }
    .danmaku-tool-btn:active {
      transform: translateY(1px);
    }
    .danmaku-tool-btn img {
      width: 22px;
      height: 22px;
      display: block;
    }

    .danmaku-settings-panel {
      position: absolute;
      left: 0;
      bottom: calc(100% + 8px);
      min-width: 220px;
      padding: 10px;
      border-radius: 8px;
      background: #ffffff;
      border: 1px solid #e1e1e1;
      box-shadow: 0 8px 18px rgba(0, 0, 0, 0.08);
      display: none;
      z-index: 8;
    }
    .danmaku-settings-panel.is-open {
      display: block;
    }
    .danmaku-settings-title {
      font-size: 12px;
      color: #444;
      margin-bottom: 8px;
      font-weight: 600;
    }
    .danmaku-settings-group + .danmaku-settings-group {
      margin-top: 12px;
    }
    #danmaku-area-range {
      width: 100%;
    }
    .danmaku-segmented {
      display: flex;
      gap: 6px;
    }
    .danmaku-segmented-btn {
      flex: 1;
      padding: 6px 4px;
      font-size: 12px;
      border-radius: 6px;
      border: 1px solid #d6dbe8;
      background: #f7f8fb;
      color: #3a3a3a;
      cursor: pointer;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
    }
    .danmaku-segmented-btn.is-active {
      background: #e6eeff;
      border-color: #5a7ff0;
      color: #2f4aa6;
      font-weight: 600;
    }
    .danmaku-segmented-btn:focus-visible {
      outline: 2px solid #5a7ff0;
      outline-offset: 2px;
    }
    .danmaku-settings-labels {
      display: flex;
      justify-content: space-between;
      font-size: 11px;
      color: #777;
      margin-top: 4px;
    }
    .danmaku-input-wrapper {
      position: relative;
      flex: 1;
      display: flex;
      align-items: center;
      background: transparent;
      border: none;
      border-radius: 0;
      box-shadow: none;
    }
    #danmaku-input {
      width: 100%;
      padding: 8px 58px 8px 8px;
      font-size: 16px;
      border: 1px solid #d1d1d1;
      border-radius: 4px;
      box-sizing: border-box;
      background: #e8eaed;
      box-shadow: none;
    }

    .danmaku-screen.is-hidden,
    .dialogue-connector-svg.is-hidden {
      opacity: 0;
      pointer-events: none;
    }
    .danmaku-ai-toggle {
      position: absolute;
      right: 10px;
      top: 50%;
      transform: translateY(-50%);
      width: 34px;
      height: 34px;
      border-radius: 50%;
      border: 1px solid #a6c0ff;
      background: linear-gradient(180deg, #ffffff 0%, #d6e4ff 100%);
      color: #0d6efd;
      font-weight: 700;
      font-size: 13px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.9),
        0 3px 6px rgba(13, 110, 253, 0.22);
      transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease, transform 0.1s ease;
    }
    .danmaku-ai-toggle.active {
      background: linear-gradient(180deg, #1f6bff 0%, #0d6efd 100%);
      border-color: #0d6efd;
      color: #fff;
      box-shadow:
        inset 0 1px 2px rgba(0, 0, 0, 0.2),
        0 0 0 4px rgba(13, 110, 253, 0.18),
        0 4px 10px rgba(13, 110, 253, 0.25);
    }
    .danmaku-ai-toggle:hover {
      box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.95),
        0 4px 10px rgba(13, 110, 253, 0.28);
    }
    .danmaku-ai-toggle:active {
      transform: translateY(-50%) translateY(1px);
      box-shadow:
        inset 0 2px 3px rgba(0, 0, 0, 0.25),
        0 1px 4px rgba(13, 110, 253, 0.25);
    }
    .danmaku-ai-toggle:focus-visible {
      outline: 2px solid #b6d4fe;
      outline-offset: 2px;
    }
    #send-danmaku-btn, .btn {
      padding: 8px 14px; font-size: 16px; border: none; background-color: #007bff; color: white;
      border-radius: 4px; cursor: pointer;
      flex-shrink: 0; transition: background-color 0.2s;
    }
    #send-danmaku-btn:hover, .btn:hover { background-color: #0056b3; }

    /* ===== 侧边栏样式 ===== */
    .sidebar {
      position: fixed; top: 20px; width: 320px; background-color: #fff;
      display: flex; flex-direction: column; box-shadow: 4px 0 15px rgba(0,0,0,0.15); z-index: 1000;
      transition: transform 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    }
    .sidebar.is-condition-hidden {
      display: none;
    }
    .sidebar-left { left: 0; border-radius: 0 8px 8px 0; transform: translateX(-100%); }
    .sidebar-right { right: 0; border-radius: 8px 0 0 8px; transform: translateX(100%); box-shadow: -4px 0 15px rgba(0,0,0,0.15); }
    .sidebar.sidebar-open { transform: translateX(0); }
    .sidebar-toggle-button {
      position: absolute; top: 50%; transform: translateY(-50%);
      width: 40px; height: 132px; background-color: #fff;
      box-shadow: 2px 0 8px rgba(0,0,0,0.1); cursor: pointer; display: flex; justify-content: center; align-items: center;
      color: #333; font-weight: bold; writing-mode: vertical-rl; letter-spacing: 0; font-size: 13px;
      text-orientation: mixed;
      white-space: nowrap;
      padding: 6px 0;
      overflow: hidden;
    }
    .sidebar-left .sidebar-toggle-button {
      right: -40px; border-radius: 0 8px 8px 0;
    }
    .sidebar-right .sidebar-toggle-button {
      left: -40px; border-radius: 8px 0 0 8px;
      box-shadow: -2px 0 8px rgba(0,0,0,0.1);
    }
    .sidebar-header { padding: 15px; border-bottom: 1px solid #e7e7e7; font-size: 16px; font-weight: bold; text-align: center; }
    .ai-sidebar-header {
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-direction: column;
      gap: 0;
      padding: 10px 15px;
      min-height: 40px;
    }
    .ai-sidebar-title {
      flex: none;
      text-align: center;
      font-weight: 700;
      font-size: 16px;
    }
    .ai-sidebar-subtitle {
      font-size: 12px;
      color: #6b7280;
    }
    #sidebar-content { flex: 1; overflow-y: auto; padding: 10px; scroll-behavior: smooth; }
    .dialogue-card { border-left: 4px solid #ddd; border-radius: 4px; margin-bottom: 12px; background-color: #f9f9f9; transition: all 0.3s; opacity: 0.7; }
    .dialogue-card.active { opacity: 1; border-color: #007bff; box-shadow: 0 2px 6px rgba(0, 123, 255, 0.2); }
    
    .dialogue-card.highlighted {
      border-color: var(--dialogue-color, #ff8c00); 
      transform: scale(1.02);
      box-shadow: 0 0 15px var(--dialogue-color, rgba(255, 140, 0, 0.6));
    }

    .card-header { padding: 12px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
    .card-title { font-weight: bold; font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; padding-right: 10px; }
    .expand-toggle { font-family: monospace; font-weight: bold; font-size: 20px; color: #999; }
    .message-list { max-height: 0; overflow: hidden; transition: max-height 0.4s ease-in-out; padding: 0 12px; }
    .dialogue-card.expanded .message-list { padding-bottom: 12px; }
    .dialogue-card.expanded .message-list.scrollable { max-height: 200px; overflow-y: auto; }
    .message-list ul { list-style-type: none; padding: 0; margin: 0; }
    .time-tag { font-size: 12px; color: #888; background-color: #eee; padding: 2px 6px; border-radius: 4px; margin-right: 8px; }
    .ai-chat {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 12px;
      padding: 8px 16px 16px;
      min-height: 0;
    }
    .ai-chat-messages {
      flex: 1; overflow-y: auto; max-height: none; border: 1px solid #e0e0e0; border-radius: 8px; padding: 12px;
      background: linear-gradient(180deg, #fdfdff 0%, #f4f6fb 100%);
    }
    .ai-message { padding: 8px 10px; border-radius: 6px; margin-bottom: 8px; font-size: 14px; line-height: 1.5; }
    .ai-message:last-child { margin-bottom: 0; }
    .ai-message.system { background-color: #fff8e6; border-left: 3px solid #f6ad55; color: #8a6d3b; }
    .ai-message.user { background-color: #dbeafe; border-right: 3px solid #3b82f6; margin-left: auto; max-width: 85%; }
    .ai-message.assistant { background-color: #eef2ff; border-left: 3px solid #6366f1; max-width: 90%; }
    .ai-message.error {
      background-color: #fde8e8;
      border-left: 3px solid #dc2626;
      color: #991b1b;
    }
    .ai-reply-mode { display: flex; align-items: center; gap: 8px; font-size: 13px; color: #555; }
    .ai-reply-mode select { padding: 4px 6px; border-radius: 6px; border: 1px solid #cbd5f5; font-size: 13px; }
    .ai-choice-block { display: flex; flex-direction: column; gap: 8px; }
    .ai-choice-buttons { display: flex; gap: 8px; flex-wrap: wrap; }
    .ai-choice-btn {
      padding: 6px 10px; border-radius: 6px; border: 1px solid #3b82f6;
      background: #e0ecff; color: #1d4ed8; cursor: pointer; font-size: 13px;
      transition: all 0.2s ease;
    }
    .ai-choice-btn:hover { background: #d0e2ff; border-color: #1d4ed8; }
    .ai-chat-input { display: flex; gap: 10px; align-items: stretch; }
    .ai-chat-input textarea {
      flex: 1; resize: none; border: 1px solid #cbd5f5; border-radius: 6px;
      padding: 8px 10px; font-size: 14px; min-height: 70px; font-family: inherit;
    }
    .ai-chat-input-actions {
      display: flex;
      flex-direction: column;
      gap: 8px;
      flex-shrink: 0;
      justify-content: center;
    }
    .ai-chat-input button {
      padding: 10px 16px; border: none; border-radius: 6px; background-color: #007bff; color: #fff;
      font-size: 15px; cursor: pointer; transition: background-color 0.2s;
      min-height: 70px; height: 100%; display: flex; align-items: center; justify-content: center;
    }
    .ai-chat-input button:disabled { background-color: #a0aec0; cursor: not-allowed; }
    .ai-video-node-btn { display: inline-flex; background-color: #6366f1; }

    .tap-indicator {
      position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%) scale(0.9);
      width: 64px; height: 64px; border-radius: 50%;
      background-repeat: no-repeat; background-position: center; background-size: contain;
      opacity: 0; pointer-events: none; z-index: 15;
      transition: opacity .2s ease, transform .2s ease; will-change: opacity, transform;
    }
    .tap-indicator.play-icon {
      background-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%2032%2032%22%3E%3Ccircle%20cx%3D%2216%22%20cy%3D%2216%22%20r%3D%2216%22%20fill%3D%22%233155d9%22%2F%3E%3Cpath%20d%3D%22M13%2010l9%206-9%206z%22%20fill%3D%22%23fff%22%2F%3E%3C%2Fsvg%3E");
    }
    .tap-indicator.pause-icon {
      background-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%2032%2032%22%3E%3Ccircle%20cx%3D%2216%22%20cy%3D%2216%22%20r%3D%2216%22%20fill%3D%22%233155d9%22%2F%3E%3Crect%20x%3D%2211%22%20y%3D%2210%22%20width%3D%223.5%22%20height%3D%2212%22%20rx%3D%221%22%20fill%3D%22%23fff%22%2F%3E%3Crect%20x%3D%2217.5%22%20y%3D%2210%22%20width%3D%223.5%22%20height%3D%2212%22%20rx%3D%221%22%20fill%3D%22%23fff%22%2F%3E%3C%2Fsvg%3E");
    }
    .tap-indicator.show { opacity: 1; transform: translate(-50%, -50%) scale(1); }

    /* ===== AI 精灵球浮窗（仅样式） ===== */
    :root {
      --ai-orb-size: 72px;
      --ai-orb-gap: 16px;
    }
    .ai-orb-wrapper {
      position: fixed;
      right: 24px;
      bottom: 24px;
      width: var(--ai-orb-size);
      height: var(--ai-orb-size);
      z-index: 1300;
    }
    /* 暂时隐藏悬浮精灵球与气泡 */
    .ai-orb-wrapper,
    #ai-popover {
      display: none !important;
    }
    .ai-orb {
      position: relative;
      width: 100%;
      height: 100%;
      border-radius: 50%;
      border: none;
      background: #fff;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
      cursor: pointer;
      overflow: visible;
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .ai-orb.is-loading {
      cursor: wait;
      opacity: 0.7;
      animation: ai-orb-pulse 1s ease-in-out infinite alternate;
    }
    .ai-orb.is-loading::after {
      content: '';
      position: absolute;
      inset: -6px;
      border-radius: 50%;
      border: 2px dashed rgba(59, 130, 246, 0.6);
      animation: ai-orb-rotate 1s linear infinite;
    }
    .ai-orb:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.24);
    }
    .ai-orb:active {
      transform: translateY(0);
      box-shadow: 0 8px 18px rgba(0, 0, 0, 0.2);
    }
    .ai-orb-icon {
      width: 100%;
      height: 100%;
      object-fit: contain;
      pointer-events: none;
      border-radius: 50%;
    }

    @keyframes ai-orb-pulse {
      from { transform: scale(1); box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18); }
      to { transform: scale(0.95); box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35); }
    }

    @keyframes ai-orb-rotate {
      from { transform: rotate(0deg); }
      to { transform: rotate(360deg); }
    }

    .ai-popover {
      position: fixed;
      right: 24px;
      bottom: calc(var(--ai-orb-size) + var(--ai-orb-gap) + 24px);
      width: 400px;
      max-width: 92vw;
      max-height: 640px;
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 18px 45px rgba(15, 23, 42, 0.25);
      transform: translateY(12px) scale(0.97);
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.2s ease, transform 0.2s ease;
      z-index: 1250;
      display: flex;
      flex-direction: column;
    }
    .ai-popover.open {
      opacity: 1;
      transform: translateY(0) scale(1);
      pointer-events: auto;
    }
    .ai-popover-header {
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 12px 16px;
      background: linear-gradient(120deg, #1f6bff 0%, #5590ff 100%);
      color: #fff;
      border-radius: 12px 12px 0 0;
      font-weight: 600;
    }
    .ai-popover-body {
      padding: 14px 16px 18px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      height: 100%;
    }
    .ai-popover-status {
      font-size: 14px;
      line-height: 1.6;
      color: #1f2933;
      background: #f3f6ff;
      border: 1px solid #d8e1ff;
      border-radius: 8px;
      padding: 10px 12px;
      box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.6);
    }
    .ai-popover-chat {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 12px;
      min-height: 0;
    }
    .ai-popover-chat .ai-chat-messages {
      flex: 1;
      min-height: 220px;
      max-height: 360px;
    }
    .ai-popover-chat .ai-chat-input textarea {
      min-height: 80px;
    }

    /* ===== Markdown 内容样式优化 ===== */
    .ai-message p {
      margin: 0 0 8px 0;
    }
    .ai-message p:last-child {
      margin-bottom: 0;
    }
    .ai-message ul,
    .ai-message ol {
      margin: 4px 0 8px 20px;
      padding: 0;
    }
    .ai-message li {
      margin-bottom: 4px;
    }
    .ai-message pre {
      background-color: rgba(0, 0, 0, 0.06);
      padding: 10px;
      border-radius: 6px;
      overflow-x: auto;
      font-family: Consolas, Monaco, "Andale Mono", monospace;
      font-size: 13px;
      margin: 8px 0;
      border: 1px solid rgba(0, 0, 0, 0.1);
    }
    .ai-message code {
      background-color: rgba(0, 0, 0, 0.06);
      padding: 2px 4px;
      border-radius: 4px;
      font-family: Consolas, Monaco, "Andale Mono", monospace;
      font-size: 0.9em;
      color: #c7254e;
    }
    .ai-message.user pre,
    .ai-message.user code {
      background-color: rgba(255, 255, 255, 0.2);
      color: inherit;
      border-color: rgba(255, 255, 255, 0.2);
    }

    /* ===== 底部热度面板 (Heatmap Panel) ===== */
    .heatmap-panel {
      --heatmap-expanded-height: 300px;
      width: 100%;
      height: var(--heatmap-expanded-height, 300px);
      background-color: #fff;
      border: 1px solid #ddd;
      border-radius: 6px;
      display: flex;
      flex-direction: column;
      box-shadow: 0 4px 12px rgba(0,0,0,0.08);
      margin: 24px 0 0;
      overflow: hidden;
      transition: height 0.35s ease;
      will-change: height;
    }
    .heatmap-panel.is-condition-hidden {
      display: none;
    }

    .heatmap-panel.is-collapsed {
      height: var(--heatmap-collapsed-height, 48px);
    }
    #heatmap-content {
      transition: opacity 0.3s ease, transform 0.35s ease;
      transform-origin: center;
      will-change: transform, opacity;
    }
    .heatmap-panel.is-collapsed #heatmap-content {
      opacity: 0;
      transform: scaleY(0.12);
      pointer-events: none;
    }

    .heatmap-header {
      --heatmap-btn-left: 12px;
      --heatmap-btn-gap: 10px;
      --heatmap-btn-width: 84px;
      padding: 10px 12px;
      border-bottom: 1px solid #e7e7e7;
      font-size: 14px;
      font-weight: 700;
      text-align: center;
      background-color: #fafafa;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
    }
    .heatmap-overview-btn {
      position: absolute;
      left: var(--heatmap-btn-left);
      top: 50%;
      transform: translateY(-50%);
      height: 24px;
      width: var(--heatmap-btn-width);
      padding: 0 8px;
      border: 1px solid #cfcfcf;
      border-radius: 12px;
      background-color: #fff;
      color: #555;
      font-size: 11px;
      font-weight: 600;
      line-height: 1;
      cursor: pointer;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
      white-space: nowrap;
    }
    .heatmap-overview-btn.is-active {
      border-color: #5a7ff0;
      color: #3058e5;
      background-color: #eef2ff;
    }
    .heatmap-wave-toggle-btn {
      position: absolute;
      left: calc(var(--heatmap-btn-left) + var(--heatmap-btn-width) + var(--heatmap-btn-gap));
      top: 50%;
      transform: translateY(-50%);
      height: 24px;
      width: var(--heatmap-btn-width);
      padding: 0 8px;
      border: 1px solid #cfcfcf;
      border-radius: 12px;
      background-color: #fff;
      color: #555;
      font-size: 11px;
      font-weight: 600;
      line-height: 1;
      cursor: pointer;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
      white-space: nowrap;
    }
    .heatmap-topic-toggle-btn {
      position: absolute;
      left: calc(var(--heatmap-btn-left) + (var(--heatmap-btn-width) + var(--heatmap-btn-gap)) * 2);
      top: 50%;
      transform: translateY(-50%);
      height: 24px;
      width: var(--heatmap-btn-width);
      padding: 0 8px;
      border: 1px solid #cfcfcf;
      border-radius: 12px;
      background-color: #fff;
      color: #555;
      font-size: 11px;
      font-weight: 600;
      line-height: 1;
      cursor: pointer;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
      white-space: nowrap;
    }
    .heatmap-wave-toggle-btn.is-active {
      border-color: #5a7ff0;
      color: #3058e5;
      background-color: #eef2ff;
    }
    .heatmap-topic-toggle-btn.is-active {
      border-color: #5a7ff0;
      color: #3058e5;
      background-color: #eef2ff;
    }
    .heatmap-wave-toggle-btn:focus-visible {
      outline: 2px solid #4d90fe;
      outline-offset: 2px;
    }
    .heatmap-topic-toggle-btn:focus-visible {
      outline: 2px solid #4d90fe;
      outline-offset: 2px;
    }
    .heatmap-overview-btn:focus-visible {
      outline: 2px solid #4d90fe;
      outline-offset: 2px;
    }
    .heatmap-header:focus-visible {
      outline: 2px solid #4d90fe;
      outline-offset: -2px;
    }
    .heatmap-title {
      pointer-events: none;
    }
    .heatmap-legend {
      position: absolute;
      right: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 12px;
      font-weight: 500;
      color: #555;
      white-space: nowrap;
      transition: opacity 0.2s ease;
    }
    .heatmap-panel.is-collapsed .heatmap-legend {
      opacity: 0;
      visibility: hidden;
      pointer-events: none;
    }
    .heatmap-legend-item {
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .heatmap-legend-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      display: inline-block;
    }
    .heatmap-legend-dot-emotion {
      background-color: #f4a9c6;
    }
    .heatmap-legend-dot-knowledge {
      background-color: #e28a1b;
    }
    .heatmap-legend-dot-interaction {
      background-color: #95d475;
    }

    #heatmap-content {
      flex: 1;
      width: 100%;
      height: 100%;
      padding: 10px 0;
      box-sizing: border-box;
      overflow-x: auto;
      overflow-y: auto;
      position: relative;
      background-color: #fcfcfc;
      scrollbar-width: none; /* Firefox */
      -ms-overflow-style: none; /* IE/Edge legacy */
    }
    #heatmap-content.is-overview {
      overflow-y: hidden;
    }
    #heatmap-content::-webkit-scrollbar {
      width: 0;
      height: 0;
    }
    #heatmap-content.heatmap-panning,
    #heatmap-content.heatmap-panning .heatmap-svg {
      cursor: grabbing;
    }

    /* SVG 图表样式 */
    .heatmap-svg {
      height: auto;
      display: block;
      vertical-align: middle;
      overflow: visible;
      cursor: crosshair;
      min-width: 100%;
      width: auto;
    }

    /* 1. 背景层：人气 (The Crowd) */
    .heatmap-area {
      fill: rgba(160, 160, 160, 0.4); /* 灰色半透明 */
      stroke: none;
      transition: d 0.3s ease;
    }

    /* 2. 前景层：回复集 (Reply Clusters) - 之字形线条 */
    .heatmap-line {
      fill: none;
      stroke-width: 2.5px;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .heatmap-line-answer {
      stroke: #FF8C00; /* 解答线 */
      filter: drop-shadow(0 2px 4px rgba(255, 140, 0, 0.35));
    }
    .heatmap-line-social {
      stroke: #73c45a; /* 社交线 */
      filter: drop-shadow(0 2px 4px rgba(115, 196, 90, 0.35));
    }
    .heatmap-line-emotion {
      stroke: #1E88E5; /* 情感线 */
      filter: drop-shadow(0 2px 4px rgba(30, 136, 229, 0.35));
    }

    /* 3. 节点 (Nodes) */
    .heatmap-node {
      transition: r 0.2s, stroke-width 0.2s;
      cursor: pointer;
      filter: drop-shadow(0 0 3px rgba(0, 0, 0, 0.4));
    }
    .heatmap-node:hover {
      r: 7 !important;
      stroke: #fff;
      stroke-width: 2px;
      z-index: 10;
    }

    .heatmap-axis-line {
      stroke: #c9c9c9;
      stroke-width: 1;
    }
    .heatmap-axis-tick {
      stroke: #bdbdbd;
      stroke-width: 1;
    }
    .heatmap-axis-text {
      fill: #666;
      font-size: 11px;
      font-family: inherit;
      dominant-baseline: middle;
      pointer-events: none;
    }
    .heatmap-topic-label {
      cursor: pointer;
      filter: drop-shadow(0 2px 6px rgba(15, 23, 42, 0.14));
    }
    .heatmap-topic-label rect,
    .heatmap-topic-label .heatmap-topic-pointer {
      fill: #f8fafc;
      stroke: #cbd5e1;
      stroke-width: 1;
      transition: fill 0.2s ease, stroke 0.2s ease;
    }
    .heatmap-topic-label:hover rect,
    .heatmap-topic-label:hover .heatmap-topic-pointer {
      fill: #eef2f7;
      stroke: #94a3b8;
    }
    .heatmap-topic-label text {
      fill: #1f2937;
      font-weight: 600;
      letter-spacing: 0.2px;
      pointer-events: none;
    }
    .heatmap-axis-wave-fill {
      fill: rgba(207, 212, 219, 0.35);
      pointer-events: none;
    }
    .heatmap-axis-wave-line {
      fill: none;
      stroke: #cfd4db;
      stroke-width: 1.2;
      pointer-events: none;
    }
    .heatmap-playhead-layer { pointer-events: none; }
    .heatmap-playhead {
      stroke: rgba(235, 87, 87, 0.85);
      stroke-width: 2;
      filter: drop-shadow(0 0 4px rgba(235, 87, 87, 0.45));
    }


    /* ===== Thread River 风格底部视图 ===== */
    .threadriver-link {
      fill: none;
      stroke: rgba(0,0,0,0.35);
      stroke-width: 1.2;
    }

    .threadriver-rail {
      stroke: rgba(0,0,0,0.25);
      stroke-width: 2;
    }

    .threadriver-arrowhead {
      fill: rgba(0,0,0,0.35);
    }

    .threadriver-hatch-line {
      stroke: rgba(0,0,0,0.35);
      stroke-width: 1.6;
      stroke-linecap: round;
    }

    .threadriver-play {
      fill: rgba(0,0,0,0.6);
      cursor: pointer;
      transition: transform 0.15s ease;
    }
    .threadriver-play:hover {
      transform: scale(1.06);
    }
    .threadriver-play-mini {
      fill: rgba(0,0,0,0.6);
      pointer-events: none;
    }

    /* 节点通用 */
    .threadriver-node {
      cursor: pointer;
      stroke: rgba(0,0,0,0.65);
      stroke-width: 1.2;
    }

    /* 普通：空心（视觉上接近论文里的空心圈/空心胶囊） */
    .threadriver-node-leaf {
      fill: #ffffff;
    }

    /* 聚合节点：浅色胶囊（可按你喜好改色） */
    .threadriver-node-cluster {
      fill: rgba(125, 183, 255, 0.65);
    }

    /* 中间节点：阴影圆（斜杠） */
    .threadriver-node-mid {
      fill: url(#threadriver-hatch);
      stroke: #4a90e2;
    }
    .threadriver-node-mid.threadriver-node-knowledge,
    .threadriver-node-mid.threadriver-node-emotion,
    .threadriver-node-mid.threadriver-node-interaction {
      stroke: #4a90e2;
    }

    .threadriver-node-root {
      fill: #3b3b3b;
    }
    .threadriver-node-root.threadriver-node-knowledge {
      fill: #e28a1b;
    }
    .threadriver-node-root.threadriver-node-interaction {
      fill: #95d475;
    }
    .threadriver-node-root.threadriver-node-emotion {
      fill: #f4a9c6;
    }

    /* 回复类型颜色 */
    .threadriver-node-knowledge {
      stroke: #e28a1b;
    }
    .threadriver-node-interaction {
      stroke: #73c45a;
    }
    .threadriver-node-emotion {
      stroke: #f4a9c6;
    }

    /* 全览模式：节点缩成实心点 */
    .threadriver-node-dot {
      stroke: none;
    }
    .threadriver-node-dot-leaf {
      fill: none;
      stroke: #1f1f1f;
      stroke-width: 1.2;
    }
    .threadriver-node-dot-mid {
      fill: #4a90e2;
    }
    .threadriver-node-dot.threadriver-node-root {
      fill: #3b3b3b;
    }
    .threadriver-node-dot.threadriver-node-root.threadriver-node-knowledge {
      fill: #e28a1b;
    }
    .threadriver-node-dot.threadriver-node-root.threadriver-node-interaction {
      fill: #95d475;
    }
    .threadriver-node-dot.threadriver-node-root.threadriver-node-emotion {
      fill: #f4a9c6;
    }