/* roulang page: index */
:root {
      --bg-main: #0B0D13;
      --bg-alt: #131620;
      --text-main: #F8FAFC;
      --text-muted: #94A3B8;
      --border-line: rgba(255, 255, 255, 0.08);
      --primary-color: #7C3AED;
      --secondary-color: #06B6D4;
      --accent-color: #F59E0B;
    }
    * {
      box-sizing: border-box;
      scroll-behavior: smooth;
    }
    body {
      background-color: var(--bg-main);
      color: var(--text-main);
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      line-height: 1.6;
      overflow-x: hidden;
    }
    .custom-glow-purple {
      box-shadow: 0 0 35px -5px rgba(124, 58, 237, 0.35);
    }
    .custom-glow-cyan {
      box-shadow: 0 0 35px -5px rgba(6, 182, 212, 0.25);
    }
    .text-gradient {
      background: linear-gradient(135deg, #F8FAFC 20%, #06B6D4 70%, #7C3AED 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .card-border {
      border: 1px solid var(--border-line);
      background: rgba(26, 31, 46, 0.65);
      backdrop-filter: blur(12px);
    }
    .card-border:hover {
      border-color: rgba(6, 182, 212, 0.4);
      transform: translateY(-2px);
      transition: all 0.3s ease;
    }
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
    }
    .faq-item.active .faq-content {
      max-height: 500px;
      transition: max-height 0.35s ease-in-out;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }