/* roulang page: index */
:root {
      --bg-base: #070d1e;
      --bg-panel: rgba(11, 22, 44, 0.75);
      --bg-card: rgba(16, 29, 58, 0.65);
      --border-cyan: rgba(0, 210, 255, 0.22);
      --border-cyan-hover: rgba(0, 210, 255, 0.55);
      --glow-cyan: 0 0 25px rgba(0, 210, 255, 0.35);
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --text-dim: #64748b;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background-color: var(--bg-base);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.6;
      overflow-x: hidden;
    }

    /* 玻璃拟态卡片 */
    .glass-card {
      background-color: var(--bg-card);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border: 1px solid var(--border-cyan);
      border-radius: 0.85rem;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .glass-card:hover {
      border-color: var(--border-cyan-hover);
      transform: translateY(-4px);
      box-shadow: 0 12px 30px rgba(0, 210, 255, 0.15);
    }

    /* 主 CTA 发光按钮 */
    .btn-glow {
      background: linear-gradient(135deg, #00d2ff 0%, #0066ff 100%);
      color: #ffffff;
      font-weight: 600;
      border: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: 0.5rem;
      transition: all 0.25s ease-in-out;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
    }

    .btn-glow:hover {
      box-shadow: var(--glow-cyan);
      transform: scale(1.02);
      color: #ffffff;
    }

    .btn-outline {
      background: rgba(11, 22, 44, 0.8);
      border: 1px solid var(--border-cyan);
      color: #00d2ff;
      font-weight: 500;
      border-radius: 0.5rem;
      transition: all 0.25s ease;
    }

    .btn-outline:hover {
      background: rgba(0, 210, 255, 0.12);
      border-color: #00d2ff;
      color: #ffffff;
    }

    /* 背景网格微光栅 */
    .cyber-grid {
      background-size: 40px 40px;
      background-image: 
        linear-gradient(to right, rgba(0, 210, 255, 0.04) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(0, 210, 255, 0.04) 1px, transparent 1px);
    }

    /* 手风琴开关动效 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, opacity 0.3s ease-out;
      opacity: 0;
    }

    .faq-item.active .faq-content {
      max-height: 260px;
      opacity: 1;
    }

    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }

    html {
      scroll-behavior: smooth;
    }

    ::selection {
      background: rgba(0, 210, 255, 0.3);
      color: #ffffff;
    }