/* roulang page: index */
:root {
      --primary: #1E40AF;
      --primary-hover: #172554;
      --secondary: #3B82F6;
      --accent: #0D9488;
      --accent-warm: #F59E0B;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --bg-dark: #0F172A;
      --text-main: #0F172A;
      --text-muted: #475569;
      --text-sub: #64748B;
      --border-color: #E2E8F0;
      --card-radius: 12px;
      --shadow-sm: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
      --shadow-hover: 0 12px 24px -4px rgba(30, 64, 175, 0.12);
      --font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-family);
      color: var(--text-main);
      background-color: var(--bg-white);
      line-height: 1.7;
      overflow-x: hidden;
    }
    a { text-decoration: none; color: inherit; }
    .site-topbar {
      background-color: #0B1329;
      color: #94A3B8;
      font-size: 13px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .status-dot {
      display: inline-block;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background-color: var(--accent);
      margin-right: 6px;
      animation: pulseDot 2s infinite ease-in-out;
    }
    @keyframes pulseDot {
      0%, 100% { opacity: 1; transform: scale(1); }
      50% { opacity: 0.4; transform: scale(0.85); }
    }
    .main-navbar {
      background-color: #ffffff;
      border-bottom: 1px solid var(--border-color);
      position: sticky;
      top: 0;
      z-index: 1020;
      padding: 14px 0;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.02);
    }
    .brand-logo-text {
      font-size: 20px;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .brand-badge {
      font-size: 11px;
      background: #EFF6FF;
      color: var(--secondary);
      padding: 2px 8px;
      border-radius: 20px;
      font-weight: 600;
    }
    .nav-link-custom {
      font-size: 15px;
      font-weight: 500;
      color: #334155;
      padding: 6px 14px;
      transition: color 0.2s;
    }
    .nav-link-custom:hover {
      color: var(--primary);
    }
    .btn-brand-primary {
      background-color: var(--primary);
      color: #ffffff;
      font-weight: 600;
      font-size: 14px;
      border-radius: 8px;
      padding: 8px 20px;
      border: 1px solid var(--primary);
      transition: all 0.2s ease-in-out;
      display: inline-block;
    }
    .btn-brand-primary:hover {
      background-color: var(--primary-hover);
      border-color: var(--primary-hover);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(30, 64, 175, 0.25);
    }
    .btn-brand-outline {
      background-color: transparent;
      color: var(--primary);
      border: 1px solid #CBD5E1;
      font-weight: 600;
      font-size: 14px;
      border-radius: 8px;
      padding: 8px 18px;
      transition: all 0.2s;
    }
    .btn-brand-outline:hover {
      background-color: #EFF6FF;
      border-color: var(--secondary);
      color: var(--primary);
    }
    .section-wrap {
      padding: 80px 0;
    }
    @media (max-width: 991px) {
      .section-wrap { padding: 50px 0; }
    }
    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary);
      background-color: #EFF6FF;
      padding: 4px 12px;
      border-radius: 4px;
      margin-bottom: 12px;
    }
    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 760px;
      margin: 0 auto 48px auto;
      line-height: 1.7;
    }
    .hero-skew-section {
      position: relative;
      background: linear-gradient(135deg, #0F172A 0%, #1E293B 55%, #1E40AF 100%);
      color: #ffffff;
      padding: 100px 0 120px 0;
      clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
      overflow: hidden;
    }
    .hero-bg-overlay {
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-image: url('/assets/images/3f104917f959a4b0.png');
      background-size: cover;
      background-position: center;
      opacity: 0.12;
      pointer-events: none;
    }
    .hero-title {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 24px;
      letter-spacing: -1px;
    }
    @media (max-width: 768px) {
      .hero-title { font-size: 28px; }
      .hero-skew-section { clip-path: none; padding: 60px 0 80px 0; }
    }
    .hero-intro {
      font-size: 17px;
      color: #E2E8F0;
      margin-bottom: 32px;
      line-height: 1.8;
      max-width: 820px;
    }
    .hero-metric-pill {
      background: rgba(255, 255, 255, 0.08);
      border: 1px solid rgba(255, 255, 255, 0.15);
      backdrop-filter: blur(8px);
      padding: 12px 20px;
      border-radius: 10px;
      margin-right: 12px;
      margin-bottom: 12px;
      display: inline-block;
    }
    .hero-metric-pill .num {
      font-size: 20px;
      font-weight: 800;
      color: #38BDF8;
      font-family: monospace;
    }
    .hero-metric-pill .lbl {
      font-size: 13px;
      color: #CBD5E1;
      margin-left: 6px;
    }
    .card-base {
      background-color: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--card-radius);
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s ease-in-out, box-shadow 0.25s ease-in-out;
      height: 100%;
    }
    .card-base:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(59, 130, 246, 0.4);
    }
    .tech-bg-dark {
      background-color: var(--bg-dark);
      color: #FFFFFF;
    }
    .tech-card {
      background-color: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: var(--card-radius);
      padding: 24px;
      height: 100%;
      transition: all 0.25s;
    }
    .tech-card:hover {
      background-color: rgba(255, 255, 255, 0.07);
      border-color: var(--secondary);
    }
    .step-badge {
      width: 42px;
      height: 42px;
      background: #EFF6FF;
      color: var(--primary);
      border-radius: 50%;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 18px;
      border: 2px solid #BFDBFE;
    }
    .metric-counter {
      font-size: 40px;
      font-weight: 800;
      font-family: monospace;
      color: var(--primary);
      line-height: 1;
      margin-bottom: 8px;
    }
    .accordion-custom .accordion-item {
      border: 1px solid var(--border-color);
      border-radius: 10px !important;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .accordion-custom .accordion-button {
      font-size: 16px;
      font-weight: 600;
      color: var(--text-main);
      background-color: #FFFFFF;
      padding: 18px 24px;
      box-shadow: none;
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      color: var(--primary);
      background-color: #F8FAFC;
    }
    .accordion-custom .accordion-button:focus {
      box-shadow: none;
      border-color: var(--border-color);
    }
    .accordion-custom .accordion-body {
      padding: 20px 24px;
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.75;
      background-color: #FFFFFF;
    }
    .footer-section {
      background-color: #090E1A;
      color: #94A3B8;
      font-size: 14px;
      padding: 70px 0 24px 0;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
    }
    .footer-title {
      font-size: 16px;
      font-weight: 700;
      color: #F8FAFC;
      margin-bottom: 20px;
    }
    .footer-link {
      color: #94A3B8;
      display: block;
      margin-bottom: 10px;
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: #FFFFFF;
    }