/* roulang page: index */
:root {
      --bg-dark: #070d18;
      --bg-card: rgba(14, 25, 48, 0.72);
      --bg-card-hover: rgba(22, 38, 70, 0.88);
      --neon-cyan: #00f0ff;
      --neon-blue: #2563eb;
      --neon-purple: #8b5cf6;
      --text-main: #f1f5f9;
      --text-muted: #94a3b8;
      --border-glass: rgba(0, 240, 255, 0.16);
      --border-solid: #1e293b;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --glow-cyan: 0 0 25px rgba(0, 240, 255, 0.28);
    }

    * { box-sizing: border-box; }
    body {
      margin: 0;
      padding: 0;
      background-color: var(--bg-dark);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      line-height: 1.6;
      padding-bottom: 70px;
    }

    a { color: var(--neon-cyan); text-decoration: none; transition: all 0.25s ease; }
    a:hover { color: #ffffff; text-decoration: none; }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(7, 13, 24, 0.88);
      backdrop-filter: blur(14px);
      border-bottom: 1px solid var(--border-glass);
      padding: 14px 0;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 1.35rem;
      font-weight: 700;
      color: #fff;
    }
    .brand-logo i { color: var(--neon-cyan); font-size: 1.5rem; }
    .nav-links {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 20px;
      margin: 0;
      list-style: none;
    }
    .nav-links a.active {
      color: var(--neon-cyan);
      font-weight: 600;
      border-bottom: 2px solid var(--neon-cyan);
      padding-bottom: 4px;
    }

    .glass-card {
      background: var(--bg-card);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
      transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    }
    .glass-card:hover {
      transform: translateY(-4px);
      border-color: rgba(0, 240, 255, 0.4);
      box-shadow: var(--glow-cyan);
    }

    .glow-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      background: linear-gradient(135deg, var(--neon-cyan), var(--neon-blue));
      color: #030816;
      font-weight: 700;
      padding: 12px 28px;
      border-radius: 30px;
      border: none;
      box-shadow: var(--glow-cyan);
      cursor: pointer;
      transition: all 0.3s ease;
    }
    .glow-btn:hover {
      background: linear-gradient(135deg, #4df3ff, #3b82f6);
      color: #000;
      box-shadow: 0 0 35px rgba(0, 240, 255, 0.55);
      transform: scale(1.02);
    }

    .section-wrap {
      padding: 64px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    .section-head {
      margin-bottom: 38px;
    }
    .section-tag {
      display: inline-block;
      font-size: 0.8rem;
      letter-spacing: 1px;
      color: var(--neon-cyan);
      background: rgba(0, 240, 255, 0.1);
      border: 1px solid rgba(0, 240, 255, 0.25);
      padding: 3px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    .section-title {
      color: #fff;
      font-size: 1.85rem;
      font-weight: 700;
      margin-bottom: 10px;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.7;
      margin: 0 auto;
    }

    .hero-search-area {
      padding: 85px 0 65px;
      background: radial-gradient(circle at 50% 20%, rgba(0, 240, 255, 0.15) 0%, transparent 65%);
      text-align: center;
    }
    .hero-title {
      font-size: 2.35rem;
      font-weight: 800;
      color: #fff;
      line-height: 1.35;
      margin-bottom: 18px;
    }
    .hero-desc {
      color: #cbd5e1;
      max-width: 820px;
      margin: 0 auto 32px;
      font-size: 1.05rem;
    }
    .search-input-box {
      max-width: 680px;
      margin: 0 auto 24px;
      position: relative;
    }
    .search-input-box input {
      background: rgba(14, 25, 48, 0.9);
      border: 1px solid var(--border-glass);
      color: #fff;
      height: 56px;
      border-radius: 28px;
      padding: 0 135px 0 24px;
      font-size: 0.95rem;
      box-shadow: 0 4px 20px rgba(0,0,0,0.4);
    }
    .search-input-box input:focus {
      background: #0d1a33;
      border-color: var(--neon-cyan);
      box-shadow: var(--glow-cyan);
    }
    .search-input-box button {
      position: absolute;
      right: 6px;
      top: 6px;
      height: 44px;
      padding: 0 24px;
    }
    .hot-tags-row {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
    }
    .hot-tag-chip {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.1);
      padding: 5px 14px;
      border-radius: 16px;
      font-size: 0.85rem;
      color: #94a3b8;
    }
    .hot-tag-chip:hover {
      border-color: var(--neon-cyan);
      color: #fff;
    }

    .diff-table {
      width: 100%;
      border-collapse: collapse;
      margin-top: 15px;
    }
    .diff-table th, .diff-table td {
      padding: 14px 18px;
      font-size: 0.92rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      text-align: left;
    }
    .diff-table th {
      color: var(--neon-cyan);
      background: rgba(0, 240, 255, 0.06);
    }

    .mobile-tab-bar {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: rgba(6, 12, 23, 0.96);
      backdrop-filter: blur(16px);
      border-top: 1px solid var(--border-glass);
      z-index: 1001;
      justify-content: space-around;
      align-items: center;
    }
    .mobile-tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.75rem;
      color: var(--text-muted);
    }
    .mobile-tab-item.active {
      color: var(--neon-cyan);
    }
    .mobile-tab-item i {
      font-size: 1.15rem;
      margin-bottom: 3px;
    }

    .site-footer {
      background: #040810;
      padding: 45px 0 30px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      font-size: 0.88rem;
      color: var(--text-muted);
    }

    @media (max-width: 768px) {
      body { padding-bottom: 75px; }
      .mobile-tab-bar { display: flex; }
      .hero-title { font-size: 1.7rem; }
      .section-title { font-size: 1.45rem; }
      .glass-card { padding: 18px; }
      .search-input-box input { padding-right: 110px; font-size: 0.85rem; }
      .search-input-box button { padding: 0 16px; font-size: 0.85rem; }
    }