/* roulang page: index */
/* 自定义设计变量与全局重置 */
    :root {
      --primary: #0A2647;
      --secondary: #144272;
      --accent: #2E8BC0;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --success: #0F766E;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 4px rgba(0,0,0,0.03);
      --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08);
      --radius-lg: 16px;
      --radius-md: 8px;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: 'Inter', 'Noto Sans SC', 'PingFang SC', system-ui, sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.6;
      margin: 0;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }
    
    /* 自定义滚动条 */
    ::-webkit-scrollbar {
      width: 6px;
    }
    ::-webkit-scrollbar-track {
      background: #f1f5f9;
    }
    ::-webkit-scrollbar-thumb {
      background: #94a3b8;
      border-radius: 8px;
    }
    
    /* 容器最大宽度 */
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    /* 卡片悬停动画 */
    .card-hover {
      transition: all 0.3s ease;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    
    /* 段落间距 */
    .section-space {
      padding-top: 6rem;
      padding-bottom: 6rem;
    }
    @media (max-width: 768px) {
      .section-space {
        padding-top: 3.5rem;
        padding-bottom: 3.5rem;
      }
      .container-custom {
        padding-left: 20px;
        padding-right: 20px;
      }
    }
    
    /* 标题下划线装饰 */
    .title-decor {
      position: relative;
      display: inline-block;
    }
    .title-decor::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 4px;
      background-color: var(--accent);
      border-radius: 2px;
    }
    
    /* 导航激活状态 */
    .nav-chip {
      transition: all 0.2s;
      cursor: pointer;
    }
    .nav-chip.active {
      background-color: var(--primary);
      color: white;
    }
    
    /* 手风琴动画 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
    }
    .faq-item.open .faq-content {
      max-height: 300px;
    }
    .faq-icon {
      transition: transform 0.2s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    
    /* 按钮焦点可见 */
    button:focus-visible, a:focus-visible, input:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }
    
    /* 移动端汉堡菜单 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 1023px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu {
        display: block;
      }
    }