:root {
      --gold: #c9a84c; --gold-light: #e8c97a; --gold-dark: #8a6820;
      --ink: #110e06; --ink-mid: #1e180a; --ink-soft: #3d2e10;
      --paper: #fdf8ef; --paper-dark: #f0e8d5;
      --text-body: #3d2e10; --text-muted: #7a6040;
      --border: rgba(201,168,76,0.25); --border-mid: rgba(201,168,76,0.4);
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body { font-family: 'Noto Serif SC', 'SimSun', serif; background: var(--paper); color: var(--text-body); line-height: 1.9; }

    /* 导航 */
    .nav { position: fixed; top: 0; left: 0; right: 0; z-index: 200; background: rgba(17,14,6,0.97); backdrop-filter: blur(8px); border-bottom: 1px solid var(--gold-dark); height: 62px; display: flex; align-items: center; justify-content: space-between; padding: 0 6%; }
    .nav-logo { color: var(--gold); font-size: 1.1rem; font-weight: 900; letter-spacing: 0.25em; text-decoration: none; }
    .nav-cta { background: var(--gold); color: var(--ink); padding: 7px 20px; font-weight: 700; border-radius: 1px; text-decoration: none; font-size: 0.88rem; }
    .nav-cta:hover { background: var(--gold-light); }

    /* 语言切换器 */
    .lang-switcher { display: flex; align-items: center; gap: 8px; }
    .lang-btn { font-size: 0.82rem; font-weight: 600; color: #c8a84a; text-decoration: none; letter-spacing: 0.06em; padding: 3px 6px; border-radius: 2px; transition: color 0.2s, background 0.2s; }
    .lang-btn:hover { color: var(--gold-light); }
    .lang-btn.active { color: #fff; background: rgba(201,168,76,0.18); }
    .lang-sep { color: rgba(201,168,76,0.4); font-size: 0.75rem; }
    @media (max-width: 480px) { .lang-switcher { display: none; } }

    /* 页头 */
    .page-hero {
      background: var(--ink);
      background-image: radial-gradient(ellipse 60% 60% at 20% 50%, rgba(201,168,76,0.07) 0%, transparent 70%);
      padding: 96px 6% 60px;
      text-align: center;
      border-bottom: 1px solid var(--gold-dark);
    }
    .page-tag { font-size: 0.7rem; letter-spacing: 0.28em; color: var(--gold); border: 1px solid rgba(201,168,76,0.35); padding: 4px 16px; display: inline-block; margin-bottom: 24px; }
    .page-hero h1 { font-size: clamp(1.5rem, 4vw, 2.4rem); color: var(--gold-light); font-weight: 700; letter-spacing: 0.06em; margin-bottom: 14px; max-width: 800px; margin-left: auto; margin-right: auto; line-height: 1.4; }
    .page-hero p { color: rgba(255,255,255,0.45); font-size: 0.92rem; max-width: 560px; margin: 0 auto; }

    /* 主体 */
    .main { max-width: 900px; margin: 0 auto; padding: 56px 6% 80px; }

    /* ── 视频嵌入区 ── */
    .video-wrap {
      position: relative;
      padding-bottom: 56.25%; /* 16:9 */
      height: 0;
      overflow: hidden;
      background: #000;
      border: 1px solid var(--gold-dark);
      margin-bottom: 36px;
      border-radius: 2px;
    }
    .video-wrap iframe {
      position: absolute;
      top: 0; left: 0;
      width: 100%; height: 100%;
      border: 0;
    }

    /* ── 章节时间轴 ── */
    .chapters {
      background: var(--ink);
      border: 1px solid var(--gold-dark);
      padding: 28px 32px;
      margin-bottom: 40px;
    }
    .chapters-title {
      font-size: 0.72rem;
      letter-spacing: 0.22em;
      color: var(--gold);
      margin-bottom: 20px;
    }
    .chapter-list { list-style: none; }
    .chapter-item {
      display: flex;
      align-items: baseline;
      gap: 16px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .chapter-item:last-child { border-bottom: none; }
    .chapter-time {
      font-size: 0.8rem;
      color: var(--gold);
      font-weight: 700;
      min-width: 44px;
      flex-shrink: 0;
      font-variant-numeric: tabular-nums;
    }
    .chapter-link {
      font-size: 0.88rem;
      color: rgba(255,255,255,0.7);
      text-decoration: none;
      line-height: 1.5;
      transition: color 0.2s;
    }
    .chapter-link:hover { color: var(--gold-light); text-decoration: underline; }

    /* ── 多视频网格 ── */
    .video-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 2px;
      background: var(--border);
      border: 1px solid var(--border);
      margin-bottom: 40px;
    }
    .video-card { background: var(--ink-mid); padding: 0; }
    .video-card-embed {
      position: relative;
      padding-bottom: 56.25%;
      height: 0;
      overflow: hidden;
      background: #000;
    }
    .video-card-embed iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; }
    .video-card-body { padding: 16px 18px 20px; }
    .video-card-num { font-size: 0.65rem; letter-spacing: 0.2em; color: var(--gold-dark); margin-bottom: 6px; }
    .video-card-title { font-size: 0.9rem; font-weight: 700; color: var(--gold-light); line-height: 1.5; }

    /* ── H2/H3 内容 ── */
    h2 { font-size: 1.4rem; color: var(--ink); font-weight: 700; margin: 48px 0 18px; padding-bottom: 12px; border-bottom: 1px solid var(--border); position: relative; letter-spacing: 0.05em; }
    h2::before { content: ''; position: absolute; bottom: -1px; left: 0; width: 40px; height: 2px; background: var(--gold); }
    h3 { font-size: 1rem; color: var(--ink-soft); font-weight: 700; margin: 22px 0 8px; padding-left: 12px; border-left: 3px solid var(--gold); }
    p { margin-bottom: 14px; font-size: 0.97rem; line-height: 1.9; }

    /* 面包屑 */
    .breadcrumb { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 36px; }
    .breadcrumb a { color: var(--gold-dark); text-decoration: none; }
    .breadcrumb a:hover { color: var(--gold); }

    /* YouTube 频道链接 */
    .channel-bar {
      background: var(--paper-dark);
      border: 1px solid var(--border);
      padding: 16px 24px;
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 40px;
      text-decoration: none;
      transition: border-color 0.2s;
    }
    .channel-bar:hover { border-color: var(--gold); }
    .channel-bar-icon { font-size: 1.4rem; flex-shrink: 0; }
    .channel-bar-text strong { display: block; font-size: 0.9rem; color: var(--ink); margin-bottom: 2px; }
    .channel-bar-text span { font-size: 0.8rem; color: var(--text-muted); }
    .channel-bar-arrow { margin-left: auto; color: var(--gold); font-size: 1rem; }

    /* 联系区 */
    .contact-section { background: var(--ink); border: 1px solid var(--gold-dark); padding: 40px; text-align: center; margin: 56px 0 0; }
    .contact-section h2 { color: var(--gold-light); border: none; margin: 0 0 10px; font-size: 1.4rem; }
    .contact-section h2::before { display: none; }
    .contact-sub { color: rgba(255,255,255,0.45); font-size: 0.88rem; margin-bottom: 28px; }
    .contact-grid { display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; margin-bottom: 24px; }
    .contact-item { text-align: center; }
    .contact-label { font-size: 0.65rem; letter-spacing: 0.22em; color: var(--gold-dark); margin-bottom: 5px; }
    .contact-value { font-size: 1rem; font-weight: 700; color: var(--gold-light); letter-spacing: 0.05em; }
    .contact-value-sm { font-size: 0.85rem; color: rgba(255,255,255,0.55); }
    .contact-divider { width: 1px; background: var(--gold-dark); align-self: stretch; }
    .btn-primary { background: var(--gold); color: var(--ink); padding: 13px 36px; font-size: 0.95rem; font-weight: 700; letter-spacing: 0.1em; text-decoration: none; border-radius: 1px; display: inline-block; transition: background 0.2s; }
    .btn-primary:hover { background: var(--gold-light); }

    /* 页脚 */
    .site-footer { background: #0e0b04; border-top: 1px solid var(--gold-dark); padding: 32px 5%; text-align: center; }
    .footer-links { display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; margin-bottom: 18px; list-style: none; }
    .footer-links a { color: #d9c07a; font-size: 0.95rem; font-weight: 600; text-decoration: none; }
    .footer-links a:hover { color: var(--gold-light); text-decoration: underline; }
    .footer-copy { font-size: 0.9rem; color: #a88a4a; line-height: 1.8; }

    @media (max-width: 640px) {
      .contact-divider { display: none; }
      .chapters { padding: 20px; }
    }