/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent: #00F0FF;
      --highlight: #FF3C5A;
      --text-main: #1A1F36;
      --text-sub: #5A6070;
      --text-weak: #9CA3B0;
      --bg-page: #F4F6FB;
      --bg-white: #FFFFFF;
      --radius-card: 12px;
      --shadow-card: 0 4px 16px rgba(10,14,39,0.06);
      --shadow-hover: 0 12px 28px rgba(10,14,39,0.12);
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航毛玻璃 */
    .header-glass {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(209,213,219,0.5);
    }
    /* 按钮规范 */
    .btn-primary {
      background-color: var(--accent);
      color: var(--primary);
      font-weight: 600;
      border-radius: 8px;
      padding: 12px 28px;
      display: inline-block;
      transition: all var(--transition);
      border: none;
      cursor: pointer;
      text-align: center;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 0 16px rgba(0,240,255,0.55);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: transparent;
      color: #1A1F36;
      font-weight: 600;
      border-radius: 8px;
      padding: 12px 28px;
      display: inline-block;
      border: 1px solid #D1D5DB;
      transition: all var(--transition);
      cursor: pointer;
    }
    .btn-secondary:hover {
      border-color: var(--accent);
      color: var(--accent);
      background: rgba(0,240,255,0.04);
    }
    .btn-outline-white {
      background: transparent;
      color: white;
      font-weight: 600;
      border-radius: 8px;
      padding: 12px 28px;
      display: inline-block;
      border: 1px solid rgba(255,255,255,0.5);
      transition: all var(--transition);
    }
    .btn-outline-white:hover {
      background: rgba(255,255,255,0.08);
      border-color: white;
    }
    /* 卡片规范 */
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      overflow: hidden;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .section-space {
      margin-top: 96px;
      margin-bottom: 96px;
    }
    @media (max-width: 768px) {
      .section-space {
        margin-top: 64px;
        margin-bottom: 64px;
      }
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 汉堡菜单 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 767px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu {
        display: block;
      }
    }
    /* FAQ动画 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.25s ease, padding 0.25s ease;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 12px;
      padding-bottom: 12px;
    }
    .faq-chevron {
      transition: transform 0.2s;
    }
    .faq-item.open .faq-chevron {
      transform: rotate(180deg);
    }
    /* 数字跳动预留 */
    .stat-number {
      font-variant-numeric: tabular-nums;
      letter-spacing: 0.5px;
    }