/* roulang page: index */
:root {
      --bg-dark: #070b14;
      --bg-surface: #0d1424;
      --bg-panel: #04070d;
      --primary: #2563eb;
      --accent: #38bdf8;
      --glow: #06b6d4;
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --border-glass: rgba(56, 189, 248, 0.15);
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-dark);
      color: var(--text-main);
    }
    .glass-card {
      background: rgba(13, 20, 36, 0.72);
      backdrop-filter: blur(14px);
      border: 1px solid var(--border-glass);
      box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.45);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: rgba(6, 182, 212, 0.45);
      transform: translateY(-3px);
    }
    .btn-glow {
      background: linear-gradient(135deg, #2563eb 0%, #38bdf8 100%);
      box-shadow: 0 0 24px rgba(56, 189, 248, 0.35);
      transition: all 0.25s ease;
    }
    .btn-glow:hover {
      box-shadow: 0 0 32px rgba(6, 182, 212, 0.6);
      transform: scale(1.02);
    }
    .btn-secondary {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.15);
      transition: all 0.25s ease;
    }
    .btn-secondary:hover {
      background: rgba(56, 189, 248, 0.1);
      border-color: #38bdf8;
      color: #38bdf8;
    }
    .tech-border {
      position: relative;
    }
    .tech-border::after {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.4), transparent);
    }
    details summary::-webkit-details-marker {
      display: none;
    }
    details[open] summary .faq-icon {
      transform: rotate(45deg);
    }