/* roulang page: index */
:root {
      --bg-dark: #0B0F19;
      --card-bg: rgba(17, 24, 39, 0.85);
      --card-border: rgba(255, 255, 255, 0.08);
      --primary-gradient: linear-gradient(135deg, #6366F1 0%, #06B6D4 100%);
      --accent-glow: rgba(99, 102, 241, 0.15);
    }
    body {
      background-color: var(--bg-dark);
      color: #9CA3AF;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      overflow-x: hidden;
    }
    .hero-glow {
      background: radial-gradient(circle at 50% 30%, rgba(99, 102, 241, 0.15) 0%, rgba(6, 182, 212, 0.05) 50%, transparent 75%);
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--card-border);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .glass-card:hover {
      border-color: rgba(99, 102, 241, 0.4);
      transform: translateY(-2px);
      box-shadow: 0 12px 30px -10px rgba(0, 0, 0, 0.7);
    }
    .btn-gradient {
      background: var(--primary-gradient);
      box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
      transition: all 0.2s ease;
    }
    .btn-gradient:hover {
      filter: brightness(1.1);
      box-shadow: 0 6px 20px rgba(6, 182, 212, 0.45);
      transform: translateY(-1px);
    }
    .text-gradient {
      background: linear-gradient(135deg, #FFFFFF 20%, #93C5FD 70%, #A5B4FC 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .faq-panel {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
    }