/* roulang page: index */
:root {
      --primary: #6366f1;
      --primary-hover: #4f46e5;
      --accent-cyan: #06b6d4;
      --accent-coral: #f43f5e;
      --bg-light: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --border-soft: rgba(226, 232, 240, 0.85);
      --shadow-sm: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
      --shadow-lg: 0 20px 25px -5px rgba(99, 102, 241, 0.12), 0 8px 10px -6px rgba(99, 102, 241, 0.08);
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-main);
      background-color: var(--bg-light);
      line-height: 1.65;
    }
    .hero-mask {
      background: linear-gradient(135deg, rgba(2, 6, 23, 0.88) 0%, rgba(15, 23, 42, 0.82) 50%, rgba(79, 70, 229, 0.7) 100%);
    }
    .custom-card {
      background: var(--bg-card);
      border: 1px solid var(--border-soft);
      box-shadow: var(--shadow-sm);
      transition: all 0.28s ease-in-out;
    }
    .custom-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
    }
    .dark-panel {
      background: radial-gradient(circle at top right, #1e1b4b 0%, #0f172a 60%, #020617 100%);
    }
    details summary::-webkit-details-marker {
      display: none;
    }