/* roulang page: index */
:root {
      --bg-deep: #0B0A1A;
      --bg-card: #1E1B2E;
      --bg-alt: #100F1C;
      --primary: #00F0FF;
      --primary-hover: #33F3FF;
      --secondary: #A855F7;
      --accent-gold: #F59E0B;
      --text-primary: #E2E0F0;
      --text-secondary: #9B97B5;
      --border-subtle: rgba(0, 240, 255, 0.08);
      --border-active: rgba(0, 240, 255, 0.35);
      --radius-card: 16px;
      --radius-btn: 12px;
      --transition-smooth: 0.3s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'Inter', 'SF Pro Text', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(11, 10, 26, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.15);
      transition: var(--transition-smooth);
    }
    .nav-link {
      color: var(--text-primary);
      font-weight: 500;
      padding: 0.5rem 0.75rem;
      border-radius: 8px;
      transition: var(--transition-smooth);
    }
    .nav-link:hover {
      color: var(--primary);
      text-shadow: 0 0 8px rgba(0,240,255,0.6);
    }
    .nav-link.active {
      color: var(--primary);
      border-bottom: 2px solid var(--primary);
      text-shadow: 0 0 8px rgba(0,240,255,0.6);
    }
    .btn-primary {
      background: var(--primary);
      color: #0B0A1A;
      font-weight: 700;
      border-radius: var(--radius-btn);
      padding: 0.7rem 1.8rem;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 12px rgba(0,240,255,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 0 24px rgba(0,240,255,0.6);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 0.7rem 1.8rem;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 16px rgba(0,240,255,0.4);
    }
    /* 卡片规范 */
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-subtle);
      transition: var(--transition-smooth);
    }
    .card:hover {
      border-color: var(--border-active);
      transform: translateY(-4px);
      box-shadow: 0 12px 24px rgba(0,0,0,0.4);
    }
    .section-spacing {
      padding-top: 100px;
      padding-bottom: 100px;
    }
    @media (max-width: 768px) {
      .section-spacing {
        padding-top: 64px;
        padding-bottom: 64px;
      }
      .card {
        border-radius: 12px;
      }
    }
    /* 汉堡菜单 */
    .mobile-menu {
      background: rgba(16, 15, 28, 0.96);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--primary);
    }
    .faq-item {
      border-left: 3px solid transparent;
      transition: border-color 0.2s ease;
    }
    .faq-item[open] {
      border-left-color: var(--primary);
    }
    .faq-summary {
      background: var(--bg-card);
      padding: 1.2rem 1.5rem;
      border-radius: 12px;
      cursor: pointer;
      font-weight: 600;
      transition: color 0.2s;
    }
    .faq-summary:hover {
      color: var(--primary);
    }
    .footer-link {
      color: var(--text-secondary);
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--primary);
    }
    input, textarea {
      background: var(--bg-card);
      border: 1px solid rgba(0,240,255,0.2);
      border-radius: 12px;
      padding: 0.8rem 1rem;
      color: white;
      transition: 0.2s;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 12px rgba(0,240,255,0.4);
    }