/* roulang page: index */
:root {
      --primary: #1e40af;
      --primary-hover: #1d4ed8;
      --accent: #0d9488;
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-muted: #64748b;
      --border-color: rgba(226, 232, 240, 0.85);
      --shadow-soft: 0 10px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.03);
      --shadow-hover: 0 20px 30px -10px rgba(30, 64, 175, 0.12), 0 10px 15px -3px rgba(15, 23, 42, 0.06);
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      background-color: var(--bg-page);
      color: var(--text-main);
      font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      overflow-x: hidden;
    }
    .med-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-soft);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .med-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: #cbd5e1;
    }
    .med-btn-primary {
      background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
      transition: all 0.25s ease;
      box-shadow: 0 4px 14px 0 rgba(29, 78, 216, 0.39);
    }
    .med-btn-primary:hover {
      background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
      box-shadow: 0 6px 20px rgba(29, 78, 216, 0.45);
      transform: translateY(-1px);
    }
    .med-btn-primary:active {
      transform: translateY(1px);
    }
    .med-badge {
      display: inline-flex;
      align-items: center;
      padding: 0.25rem 0.75rem;
      border-radius: 9999px;
      font-size: 0.75rem;
      font-weight: 600;
      letter-spacing: 0.025em;
    }
    .code-accent {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    }
    .nav-blur {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }
    .step-line::after {
      content: '';
      position: absolute;
      top: 50%;
      right: -24px;
      width: 24px;
      height: 2px;
      border-top: 2px dashed #94a3b8;
      z-index: 1;
    }
    @media (max-width: 1023px) {
      .step-line::after {
        display: none;
      }
    }
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, padding 0.3s ease;
    }
    .faq-item.active .faq-content {
      max-height: 240px;
      padding-top: 0.75rem;
      padding-bottom: 0.5rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }