/* roulang page: index */
:root {
      --primary: #0F4C81;
      --primary-dark: #0A3459;
      --accent: #FF6B35;
      --bg-slate: #F8FAFC;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-color: #E2E8F0;
    }
    body {
      color: var(--text-body);
      background-color: var(--bg-slate);
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Heiti SC", sans-serif;
      line-height: 1.75;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, h5, h6 {
      color: var(--text-main);
      line-height: 1.3;
    }
    .custom-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 0.75rem;
      transition: all 0.25s ease-in-out;
    }
    .custom-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 28px -6px rgba(15, 76, 129, 0.12);
      border-color: #CBD5E1;
    }
    .hero-bg-overlay {
      background: linear-gradient(135deg, rgba(10, 25, 47, 0.92) 0%, rgba(15, 76, 129, 0.88) 100%);
    }
    details summary::-webkit-details-marker {
      display: none;
    }
    details[open] summary svg {
      transform: rotate(180deg);
    }