/* roulang page: index */
:root {
      --primary: #7C3AED;
      --primary-dark: #4F46E5;
      --accent: #06B6D4;
      --cta: #F59E0B;
      --dark-bg: #0F172A;
      --text-main: #0F172A;
      --text-body: #475569;
      --text-muted: #94A3B8;
      --text-on-dark: #CBD5E1;
      --card-bg: #FFFFFF;
      --bg: #F8FAFC;
      --radius-xl: 24px;
      --radius-lg: 16px;
      --radius-md: 12px;
      --shadow-card: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
      --shadow-hover: 0 20px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.03);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .font-mono, .stat-number, .badge {
      font-family: 'Inter', -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    h1, h2, h3 {
      color: var(--text-main);
      font-weight: 700;
    }
    .gradient-text {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .gradient-bg {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    }
    .accent-gradient {
      background: linear-gradient(135deg, var(--accent), var(--primary));
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-xl);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(124, 58, 237, 0.2);
    }
    .badge-pill {
      background: linear-gradient(135deg, var(--accent), var(--primary));
      color: white;
      font-weight: 600;
      font-size: 0.875rem;
      padding: 6px 16px;
      border-radius: 999px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: transform 0.2s;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
      color: white;
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 14px 32px;
      transition: all 0.25s ease;
      box-shadow: 0 10px 15px -3px rgba(124, 58, 237, 0.2);
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      transform: scale(1.05);
      box-shadow: 0 15px 25px -5px rgba(124, 58, 237, 0.3);
      background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 14px 32px;
      transition: all 0.25s ease;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(124, 58, 237, 0.08);
    }
    .btn-cta {
      background: var(--cta);
      color: white;
      font-weight: 700;
      border-radius: var(--radius-md);
      padding: 14px 32px;
      transition: all 0.25s ease;
      box-shadow: 0 8px 15px -3px rgba(245, 158, 11, 0.3);
      border: none;
      cursor: pointer;
    }
    .btn-cta:hover {
      filter: brightness(1.1);
      box-shadow: 0 15px 25px -5px rgba(245, 158, 11, 0.4);
    }
    .nav-link {
      position: relative;
      font-weight: 500;
      color: var(--text-body);
      transition: color 0.2s;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .hero-visual {
      background: radial-gradient(circle at 30% 30%, rgba(124,58,237,0.15), transparent 60%);
      border-radius: 32px;
      transform: rotate(1deg);
      transition: transform 0.3s;
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-on-dark);
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding-top: 12px;
    }
    .faq-item i {
      transition: transform 0.3s;
    }
    .faq-item.open i {
      transform: rotate(45deg);
      color: var(--primary);
    }
    .masonry {
      column-count: 2;
      column-gap: 24px;
    }
    @media (max-width: 768px) {
      .masonry {
        column-count: 1;
      }
      .btn-primary, .btn-outline, .btn-cta {
        width: 100%;
        display: block;
      }
    }
    #mobile-menu {
      transition: transform 0.3s ease;
      transform: translateX(100%);
    }
    #mobile-menu.open {
      transform: translateX(0);
    }
    .decor-line {
      background: linear-gradient(90deg, transparent, rgba(124,58,237,0.2), transparent);
      height: 1px;
    }
    input, textarea {
      border-radius: 12px;
      border: 1px solid #e2e8f0;
      padding: 12px 16px;
      width: 100%;
      font-size: 1rem;
      transition: border 0.2s;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(124,58,237,0.1);
    }