/* roulang page: index */
:root {
      --bg-base: #0b111e;
      --bg-surface: #131c2e;
      --bg-surface-elevated: #1a273f;
      --primary: #10b981;
      --primary-hover: #059669;
      --accent-cyan: #06b6d4;
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --border-color: rgba(255, 255, 255, 0.08);
      --border-highlight: rgba(16, 185, 129, 0.3);
      --glow-shadow: 0 10px 30px -10px rgba(16, 185, 129, 0.2);
      --card-radius: 14px;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background-color: var(--bg-base);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
      line-height: 1.6;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

    /* TopBar */
    .top-meta-bar {
      background: #060b13;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.8125rem;
      color: var(--text-muted);
    }
    .pulse-dot {
      display: inline-block;
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      box-shadow: 0 0 8px var(--primary);
      animation: pulse 2s infinite;
    }
    @keyframes pulse {
      0% { opacity: 0.4; transform: scale(0.9); }
      50% { opacity: 1; transform: scale(1.15); }
      100% { opacity: 0.4; transform: scale(0.9); }
    }

    /* Navbar */
    .site-nav {
      background: rgba(11, 17, 30, 0.85);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--border-color);
      position: sticky;
      top: 0;
      z-index: 1030;
      transition: background 0.3s ease;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      font-size: 1.35rem;
      letter-spacing: -0.5px;
      color: var(--text-main);
    }
    .brand-logo i {
      color: var(--primary);
      font-size: 1.6rem;
    }
    .nav-link {
      color: var(--text-muted) !important;
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0.85rem !important;
      border-radius: 8px;
    }
    .nav-link:hover {
      color: var(--text-main) !important;
      background: rgba(255, 255, 255, 0.04);
    }
    .timeline-chip {
      background: rgba(16, 185, 129, 0.12);
      border: 1px solid rgba(16, 185, 129, 0.4);
      color: #34d399;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 999px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    /* Buttons */
    .btn-brand-primary {
      background: var(--primary);
      color: #042f1e;
      font-weight: 700;
      border: none;
      padding: 0.75rem 1.75rem;
      border-radius: 10px;
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-brand-primary:hover {
      background: #34d399;
      color: #042f1e;
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
    }
    .btn-brand-outline {
      background: rgba(255, 255, 255, 0.03);
      color: var(--text-main);
      font-weight: 600;
      border: 1px solid var(--border-color);
      padding: 0.75rem 1.65rem;
      border-radius: 10px;
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-brand-outline:hover {
      border-color: rgba(255, 255, 255, 0.25);
      background: rgba(255, 255, 255, 0.08);
      color: #fff;
      transform: translateY(-2px);
    }

    /* Sections */
    .sec-wrap {
      padding: 5rem 0;
      position: relative;
    }
    .sec-alt {
      background: #0f1828;
    }
    .sec-highlight {
      background: linear-gradient(180deg, #0b111e 0%, #111a2d 100%);
    }
    .section-eyebrow {
      color: var(--primary);
      font-size: 0.85rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1.5px;
      margin-bottom: 0.5rem;
      display: inline-block;
    }
    .section-title {
      font-size: 2.15rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 1rem;
      letter-spacing: -0.5px;
    }
    .section-desc {
      color: var(--text-muted);
      max-width: 760px;
      font-size: 1.05rem;
      margin: 0 auto;
    }

    /* Cards */
    .custom-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--card-radius);
      padding: 1.75rem;
      transition: all 0.3s ease;
      height: 100%;
    }
    .custom-card:hover {
      border-color: var(--border-highlight);
      transform: translateY(-4px);
      box-shadow: var(--glow-shadow);
    }

    /* Hero Showcase */
    .hero-container {
      position: relative;
      background: radial-gradient(circle at 50% 20%, rgba(16, 185, 129, 0.12) 0%, transparent 70%), url('/assets/images/3a2559212f2d8b0c.jpg') center/cover no-repeat;
      padding: 6rem 0 4rem;
      border-bottom: 1px solid var(--border-color);
    }
    .hero-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(11, 17, 30, 0.86);
      backdrop-filter: blur(2px);
    }
    .hero-series-strip {
      background: rgba(19, 28, 46, 0.7);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-color);
      border-radius: 16px;
      padding: 1rem 1.5rem;
      margin-top: 3.5rem;
    }
    .series-item {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 0.75rem;
      border-radius: 10px;
      transition: background 0.2s;
    }
    .series-item:hover {
      background: rgba(255, 255, 255, 0.05);
    }
    .series-icon {
      width: 42px;
      height: 42px;
      border-radius: 8px;
      background: rgba(16, 185, 129, 0.15);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.15rem;
    }

    /* Stat Cards */
    .stat-number {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.1;
      color: #34d399;
      font-feature-settings: "tnum";
    }

    /* Comparison Table */
    .custom-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      background: var(--bg-surface);
      border-radius: var(--card-radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
    }
    .custom-table th, .custom-table td {
      padding: 1.2rem 1.5rem;
      border-bottom: 1px solid var(--border-color);
      vertical-align: middle;
    }
    .custom-table th {
      background: rgba(255, 255, 255, 0.02);
      font-weight: 700;
      color: var(--text-main);
    }
    .custom-table tr:last-child td {
      border-bottom: none;
    }
    .col-highlight {
      background: rgba(16, 185, 129, 0.06);
      border-left: 1px solid rgba(16, 185, 129, 0.2);
      border-right: 1px solid rgba(16, 185, 129, 0.2);
    }

    /* Timeline Section */
    .timeline-step {
      position: relative;
      padding-left: 2.5rem;
      margin-bottom: 2.5rem;
    }
    .timeline-step::before {
      content: '';
      position: absolute;
      left: 11px;
      top: 8px;
      bottom: -32px;
      width: 2px;
      background: var(--border-color);
    }
    .timeline-step:last-child::before {
      display: none;
    }
    .timeline-marker {
      position: absolute;
      left: 0;
      top: 0;
      width: 24px;
      height: 24px;
      border-radius: 50%;
      background: var(--bg-surface);
      border: 3px solid var(--primary);
    }

    /* Accordion */
    .accordion-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 10px !important;
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .accordion-button {
      background: var(--bg-surface);
      color: var(--text-main);
      font-weight: 600;
      font-size: 1.05rem;
      padding: 1.25rem 1.5rem;
      box-shadow: none !important;
    }
    .accordion-button:not(.collapsed) {
      background: rgba(16, 185, 129, 0.08);
      color: #34d399;
    }
    .accordion-button::after {
      filter: invert(1);
    }
    .accordion-body {
      background: var(--bg-surface);
      color: var(--text-muted);
      line-height: 1.7;
      padding: 0 1.5rem 1.5rem;
    }

    /* Form Controls */
    .form-control, .form-select {
      background: rgba(11, 17, 30, 0.8);
      border: 1px solid var(--border-color);
      color: var(--text-main);
      border-radius: 8px;
      padding: 0.75rem 1rem;
    }
    .form-control:focus, .form-select:focus {
      background: rgba(11, 17, 30, 0.95);
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
      color: #fff;
    }

    /* Footer */
    .site-footer {
      background: #060a12;
      border-top: 1px solid var(--border-color);
      color: var(--text-muted);
      font-size: 0.9rem;
      padding: 4.5rem 0 2rem;
    }
    .footer-title {
      color: var(--text-main);
      font-weight: 700;
      margin-bottom: 1.25rem;
    }
    .footer-links li {
      margin-bottom: 0.6rem;
    }
    .footer-links a:hover {
      color: var(--primary);
      padding-left: 4px;
    }

    @media (max-width: 991.98px) {
      .hero-series-strip {
        margin-top: 2rem;
      }
      .sec-wrap {
        padding: 3.5rem 0;
      }
      .section-title {
        font-size: 1.8rem;
      }
    }