/* roulang page: index */
:root {
      --primary: #1E3A8A;
      --primary-dark: #0F172A;
      --primary-light: #2563EB;
      --secondary-teal: #0D9488;
      --accent-amber: #F59E0B;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-color: #E2E8F0;
      --radius-sm: 4px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.05), 0 1px 2px rgba(15, 23, 42, 0.03);
      --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -1px rgba(15, 23, 42, 0.04);
      --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.1), 0 4px 6px -2px rgba(15, 23, 42, 0.05);
      --transition: all 0.25s ease-in-out;
    }

    /* Reset & Base Typography */
    * { box-sizing: border-box; }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      color: var(--text-body);
      background-color: var(--bg-light);
      line-height: 1.75;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, h5, h6 {
      color: var(--text-main);
      font-weight: 700;
      letter-spacing: -0.01em;
      line-height: 1.35;
      margin-top: 0;
    }
    p { margin-bottom: 1.15rem; }
    a { color: var(--primary-light); text-decoration: none; transition: var(--transition); }
    a:hover { color: var(--primary); }
    img { max-width: 100%; height: auto; display: block; border-radius: var(--radius-md); }

    /* Layout Spacing */
    .section-wrap {
      padding: 5rem 0;
      position: relative;
    }
    .section-white { background-color: var(--bg-white); }
    .section-gray { background-color: var(--bg-light); }
    .section-dark { background-color: var(--primary-dark); color: #F1F5F9; }
    .section-dark h2, .section-dark h3, .section-dark h4 { color: #FFFFFF; }
    .section-dark p { color: #94A3B8; }
    .section-indigo { background: linear-gradient(135deg, #1E3A8A 0%, #0F172A 100%); color: #FFFFFF; }

    /* Section Header */
    .section-title-wrap {
      margin-bottom: 3.5rem;
      max-width: 820px;
    }
    .section-badge {
      display: inline-block;
      font-size: 0.8125rem;
      font-weight: 600;
      color: var(--secondary-teal);
      background-color: rgba(13, 148, 136, 0.1);
      padding: 0.25rem 0.75rem;
      border-radius: var(--radius-sm);
      margin-bottom: 0.75rem;
      border: 1px solid rgba(13, 148, 136, 0.2);
    }
    .section-title {
      font-size: 2.125rem;
      margin-bottom: 1rem;
    }
    .section-desc {
      font-size: 1.0625rem;
      color: var(--text-muted);
      line-height: 1.8;
      margin-bottom: 0;
    }
    .section-dark .section-desc { color: #94A3B8; }

    /* Component: Buttons */
    .btn-main {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background-color: var(--primary);
      color: #FFFFFF !important;
      font-weight: 600;
      padding: 0.85rem 1.75rem;
      border-radius: var(--radius-sm);
      border: 1px solid var(--primary);
      transition: var(--transition);
      cursor: pointer;
      min-height: 46px;
    }
    .btn-main:hover {
      background-color: var(--primary-light);
      border-color: var(--primary-light);
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
      transform: translateY(-2px);
    }
    .btn-secondary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background-color: transparent;
      color: var(--primary) !important;
      font-weight: 600;
      padding: 0.85rem 1.75rem;
      border-radius: var(--radius-sm);
      border: 1px solid #CBD5E1;
      transition: var(--transition);
      cursor: pointer;
      min-height: 46px;
    }
    .btn-secondary:hover {
      background-color: #F1F5F9;
      border-color: var(--primary);
      transform: translateY(-2px);
    }
    .btn-amber {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background-color: var(--accent-amber);
      color: #0F172A !important;
      font-weight: 700;
      padding: 0.85rem 1.75rem;
      border-radius: var(--radius-sm);
      border: 1px solid var(--accent-amber);
      transition: var(--transition);
    }
    .btn-amber:hover {
      background-color: #D97706;
      box-shadow: 0 4px 12px rgba(245, 158, 11, 0.35);
      transform: translateY(-2px);
    }

    /* Component: Cards */
    .feature-card {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 2rem;
      height: 100%;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
      border-color: #CBD5E1;
    }
    .card-dark-mode {
      background: #1E293B;
      border-color: #334155;
    }
    .card-dark-mode:hover {
      border-color: var(--secondary-teal);
    }

    /* Header Nav */
    .gov-topbar {
      background-color: var(--primary-dark);
      color: #94A3B8;
      font-size: 0.8125rem;
      padding: 0.45rem 0;
      border-bottom: 1px solid #1E293B;
    }
    .gov-topbar a { color: #CBD5E1; margin-left: 1.25rem; }
    .gov-topbar a:hover { color: #FFFFFF; }
    
    .gov-navbar {
      background-color: var(--bg-white);
      border-bottom: 1px solid var(--border-color);
      padding: 0.75rem 0;
      position: sticky;
      top: 0;
      z-index: 100;
      box-shadow: 0 2px 4px rgba(15, 23, 42, 0.04);
    }
    .logo-container {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      text-decoration: none;
    }
    .logo-badge {
      background-color: var(--primary);
      color: #FFFFFF;
      font-size: 1.15rem;
      font-weight: 800;
      padding: 0.35rem 0.65rem;
      border-radius: var(--radius-sm);
    }
    .logo-title {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--primary-dark);
      line-height: 1.2;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 1.5rem;
      margin: 0;
      list-style: none;
    }
    .nav-links a {
      font-weight: 600;
      color: var(--text-body);
      font-size: 0.9375rem;
      padding: 0.5rem 0;
      position: relative;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 2px;
      background-color: var(--primary);
    }

    /* Section 1: Hero Split Before / After */
    .hero-split-container {
      padding: 4.5rem 0 3.5rem;
      background: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
      border-bottom: 1px solid var(--border-color);
    }
    .hero-compare-box {
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      background: #FFFFFF;
      box-shadow: var(--shadow-md);
    }
    .hero-compare-header {
      padding: 1rem 1.25rem;
      font-weight: 700;
      font-size: 0.95rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .hero-compare-header.before {
      background: #FEF2F2;
      color: #991B1B;
      border-bottom: 1px solid #FEE2E2;
    }
    .hero-compare-header.after {
      background: #ECFDF5;
      color: #065F46;
      border-bottom: 1px solid #D1FAE5;
    }
    .hero-compare-content {
      padding: 1.5rem;
    }
    .hero-compare-list {
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .hero-compare-list li {
      padding: 0.65rem 0;
      border-bottom: 1px dashed var(--border-color);
      font-size: 0.9rem;
      display: flex;
      justify-content: space-between;
    }
    .hero-compare-list li:last-child { border-bottom: none; }

    /* Section 5: Engine Benchmark Table */
    .benchmark-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      background: #FFFFFF;
    }
    .benchmark-table th, .benchmark-table td {
      padding: 1.15rem 1.25rem;
      border-bottom: 1px solid var(--border-color);
      text-align: left;
    }
    .benchmark-table th {
      background-color: #F1F5F9;
      font-weight: 700;
      color: var(--text-main);
    }
    .benchmark-table tr:last-child td { border-bottom: none; }
    .benchmark-table tr:hover td { background-color: #F8FAFC; }
    .benchmark-win {
      color: var(--secondary-teal);
      font-weight: 700;
    }

    /* Section 7: Milestones Timeline */
    .milestone-item {
      position: relative;
      padding-left: 2rem;
      border-left: 2px solid #CBD5E1;
      margin-bottom: 2.25rem;
    }
    .milestone-dot {
      position: absolute;
      left: -9px;
      top: 4px;
      width: 16px;
      height: 16px;
      border-radius: 50%;
      background-color: var(--primary);
      border: 3px solid #FFFFFF;
      box-shadow: 0 0 0 2px var(--primary);
    }

    /* Section 9: Stats Bar */
    .stat-badge-num {
      font-size: 2.5rem;
      font-weight: 800;
      line-height: 1;
      margin-bottom: 0.5rem;
      color: #38BDF8;
    }

    /* Accordion FAQ */
    .accordion-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      margin-bottom: 0.75rem;
      overflow: hidden;
    }
    .accordion-title {
      padding: 1.25rem 1.5rem;
      font-weight: 700;
      color: var(--text-main);
      cursor: pointer;
      display: block;
      background: #FFFFFF;
      border-bottom: 1px solid transparent;
    }
    .accordion-title:hover { background: #F8FAFC; color: var(--primary); }
    .accordion-content {
      padding: 1.25rem 1.5rem;
      border-top: 1px solid var(--border-color);
      background-color: #F8FAFC;
    }

    /* Form Styles */
    .form-control-input {
      width: 100%;
      height: 48px;
      padding: 0.75rem 1rem;
      border: 1px solid #CBD5E1;
      border-radius: var(--radius-sm);
      background: #FFFFFF;
      margin-bottom: 1.25rem;
      font-size: 0.95rem;
    }
    .form-control-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(30, 58, 138, 0.15);
    }

    /* Footer */
    .gov-footer {
      background-color: #0B1120;
      color: #94A3B8;
      padding: 4.5rem 0 2rem;
      font-size: 0.9rem;
      border-top: 1px solid #1E293B;
    }
    .gov-footer h4 {
      color: #F1F5F9;
      font-size: 1.05rem;
      margin-bottom: 1.25rem;
    }
    .gov-footer ul { list-style: none; margin: 0; padding: 0; }
    .gov-footer ul li { margin-bottom: 0.65rem; }
    .gov-footer ul li a { color: #94A3B8; }
    .gov-footer ul li a:hover { color: #FFFFFF; }
    .footer-bottom {
      margin-top: 3.5rem;
      padding-top: 1.5rem;
      border-top: 1px solid #1E293B;
      text-align: center;
      font-size: 0.8125rem;
      color: #64748B;
    }

    /* Responsive Adjustments */
    @media print, screen and (max-width: 63.99875em) {
      .nav-links { display: none; }
      .section-title { font-size: 1.75rem; }
      .section-wrap { padding: 3.5rem 0; }
    }