/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --deep-bg: #0A1A3A;
      --darker-bg: #060E1F;
      --mid-bg: #0D2149;
      --neon-cyan: #00F0FF;
      --neon-cyan-dark: #00B8D4;
      --text-primary: rgba(255,255,255,0.92);
      --text-secondary: rgba(255,255,255,0.65);
      --text-muted: rgba(255,255,255,0.45);
      --glass-bg: rgba(255,255,255,0.03);
      --glass-border: rgba(0,240,255,0.15);
      --glass-border-hover: rgba(0,240,255,0.35);
      --card-shadow: 0 8px 32px rgba(0,0,0,0.4);
      --glow-neon: 0 0 20px rgba(0,240,255,0.5);
      --radius-card: 20px;
      --radius-btn: 12px;
      --radius-tag: 8px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background: radial-gradient(circle at 30% 10%, #0D2149 0%, #060E1F 85%);
      background-attachment: fixed;
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    /* 自定义容器宽度，配合Tailwind */
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 玻璃拟态卡片通用 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: var(--glass-border-hover);
      box-shadow: 0 12px 36px rgba(0,0,0,0.6), 0 0 20px rgba(0,240,255,0.2);
    }
    /* 霓虹主按钮 */
    .btn-primary {
      background: linear-gradient(135deg, #00F0FF 0%, #00B8D4 100%);
      border: none;
      color: #0A1A3A;
      font-weight: 700;
      padding: 0.9rem 2.2rem;
      border-radius: var(--radius-btn);
      letter-spacing: 0.5px;
      transition: all 0.25s;
      box-shadow: 0 4px 14px rgba(0,240,255,0.35);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      cursor: pointer;
    }
    .btn-primary:hover {
      box-shadow: 0 0 28px rgba(0,240,255,0.7);
      transform: scale(1.03);
      color: #0A1A3A;
    }
    /* 次按钮（轮廓霓虹） */
    .btn-outline {
      background: transparent;
      border: 1px solid rgba(0,240,255,0.45);
      color: var(--neon-cyan);
      font-weight: 600;
      padding: 0.85rem 2rem;
      border-radius: var(--radius-btn);
      backdrop-filter: blur(4px);
      transition: all 0.25s;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
      border-color: var(--neon-cyan);
      box-shadow: 0 0 20px rgba(0,240,255,0.4);
    }
    /* 导航链接样式 */
    .nav-link {
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover {
      color: var(--neon-cyan);
    }
    /* 霓虹下划线装饰 */
    .neon-underline {
      background: linear-gradient(90deg, transparent, var(--neon-cyan), transparent);
      height: 2px;
      width: 60px;
      margin: 0.5rem auto 0;
    }
    /* 手风琴动画 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .faq-item.active .faq-content {
      max-height: 150px; 
    }
    /* 移动端汉堡菜单全屏面板 */
    .mobile-menu {
      background: rgba(10,26,58,0.96);
      backdrop-filter: blur(28px);
      -webkit-backdrop-filter: blur(28px);
    }
    /* 数据数字等宽 */
    .stat-number {
      font-feature-settings: "tnum";
      font-variant-numeric: tabular-nums;
    }
    /* 响应式辅助 */
    @media (max-width: 768px) {
      .glass-card {
        border-radius: 16px;
      }
    }