/* roulang page: index */
:root {
      --primary: #1D4ED8;
      --primary-dark: #1E40AF;
      --accent-blue: #0284C7;
      --accent-teal: #0D9488;
      --slate-dark: #0F172A;
      --slate-text: #334155;
      --slate-light: #F8FAFC;
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Heiti SC", sans-serif;
    }
    .hero-bg {
      background: linear-gradient(135deg, rgba(15, 23, 42, 0.92) 0%, rgba(29, 78, 216, 0.85) 100%), url('/assets/images/194762a1f8aa1e60.webp') center/cover no-repeat;
    }
    .dark-band {
      background: linear-gradient(180deg, #0F172A 0%, #1E293B 100%);
    }
    .custom-shadow {
      box-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .custom-shadow:hover {
      box-shadow: 0 12px 28px -4px rgba(15, 23, 42, 0.12);
      transform: translateY(-4px);
    }
    details > summary {
      list-style: none;
    }
    details > summary::-webkit-details-marker {
      display: none;
    }
    details[open] summary .faq-icon {
      transform: rotate(180deg);
    }