/* roulang page: index */
:root {
      --primary: #0F52BA;
      --primary-dark: #0C3E8A;
      --secondary: #00D084;
      --navy: #0B132B;
      --surface: #F8FAFC;
      --card-border: rgba(226, 232, 240, 0.9);
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      background-color: #F8FAFC;
      color: #334155;
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    .hero-skew-bg {
      clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
    }
    .tabular-nums {
      font-variant-numeric: tabular-nums;
    }
    .glass-nav {
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }
    .card-hover {
      transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.28s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: 0 16px 30px -10px rgba(15, 82, 186, 0.12);
    }
    summary::-webkit-details-marker {
      display: none;
    }
    summary {
      list-style: none;
    }
    details[open] summary svg {
      transform: rotate(180deg);
    }