/* roulang page: index */
:root {
      --primary: #4F46E5;
      --primary-light: #6366F1;
      --accent-cyan: #06B6D4;
      --bg-slate: #0F172A;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      line-height: 1.75;
      color: var(--text-body);
      background-color: #F8FAFC;
      -webkit-font-smoothing: antialiased;
    }
    .scroll-mt-header {
      scroll-margin-top: 5rem;
    }
    .hero-bg-overlay {
      background: linear-gradient(135deg, rgba(15, 23, 42, 0.92) 0%, rgba(30, 41, 59, 0.88) 100%);
    }
    .cyber-glow {
      box-shadow: 0 0 35px -5px rgba(99, 102, 241, 0.35);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .accordion-content.active {
      max-height: 240px;
    }