/* roulang page: index */
:root {
      --brand-dark: #0F172A;
      --brand-navy: #0B0F19;
      --brand-primary: #0284C7;
      --brand-accent: #10B981;
      --brand-amber: #F59E0B;
      --surface-light: #F8FAFC;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --border-subtle: rgba(226, 232, 240, 0.8);
      --border-dark: rgba(255, 255, 255, 0.12);
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }
    body {
      background-color: var(--surface-light);
      color: var(--text-main);
      line-height: 1.75;
      overflow-x: hidden;
    }
    .custom-container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }
    .glass-nav {
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }
    .hero-glow {
      background: radial-gradient(circle at 50% 30%, rgba(2, 132, 199, 0.15) 0%, rgba(15, 23, 42, 0) 70%);
    }
    .card-transition {
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .card-transition:hover {
      transform: translateY(-4px);
    }
    .section-dark {
      background-color: var(--brand-navy);
      color: #F1F5F9;
    }
    /* 解决原生 details 展开箭头体验 */
    details summary::-webkit-details-marker {
      display: none;
    }
    details summary {
      list-style: none;
    }