/* roulang page: index */
:root {
      --primary: #2C5F7C;
      --primary-dark: #234B63;
      --accent: #00B4D8;
      --accent-light: rgba(0, 180, 216, 0.12);
      --bg-page: #F7F9FC;
      --bg-card: #FFFFFF;
      --bg-alt: #E9EEF3;
      --text-primary: #1A2B3C;
      --text-secondary: #5C6B7A;
      --text-muted: #8A98A6;
      --success: #10B981;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 4px 8px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.1);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 20px;
      --transition: 200ms ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航栏 */
    .navbar {
      background: white;
      border-bottom: 1px solid var(--bg-alt);
      position: sticky;
      top: 0;
      z-index: 50;
      transition: var(--transition);
    }
    .nav-link {
      color: var(--text-secondary);
      font-size: 0.875rem;
      font-weight: 500;
      transition: color 0.2s;
      text-decoration: none;
      padding: 0.5rem 0;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.625rem 1.5rem;
      font-weight: 600;
      transition: background-color 0.2s, transform 0.15s;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
      text-decoration: none;
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      border-radius: var(--radius-btn);
      padding: 0.625rem 1.5rem;
      font-weight: 600;
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
      cursor: pointer;
      text-decoration: none;
      background-color: white;
    }
    .btn-outline:hover {
      background-color: var(--accent);
      color: white;
      border-color: var(--accent);
    }
    .btn-accent {
      background-color: var(--accent);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 1.75rem;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: filter 0.2s, transform 0.1s;
      display: inline-block;
      text-decoration: none;
    }
    .btn-accent:hover {
      filter: brightness(1.1);
    }
    .btn-accent:active {
      transform: scale(0.97);
    }
    /* 卡片风格 */
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.25s, transform 0.25s;
      padding: 1.75rem;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .section-title {
      font-size: 1.5rem;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 0.75rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 3px;
      background-color: var(--accent);
      border-radius: 2px;
    }
    .text-accent {
      color: var(--accent);
    }
    .bg-soft {
      background-color: var(--bg-alt);
    }
    .divider {
      height: 1px;
      background-color: var(--bg-alt);
      margin: 1.5rem 0;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--bg-alt);
    }
    .faq-question {
      font-weight: 600;
      color: var(--text-primary);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1rem 0;
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background-color: var(--bg-alt);
      border-radius: 8px;
      margin-bottom: 0.5rem;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      font-size: 1.25rem;
      color: var(--accent);
      transition: transform 0.3s;
    }
    /* 汉堡菜单 */
    .mobile-menu {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: white;
      border-top: 1px solid var(--bg-alt);
    }
    .mobile-menu.open {
      max-height: 320px;
    }
    /* 数据动画 */
    @keyframes countUp {
      from { opacity: 0; transform: translateY(8px); }
      to { opacity: 1; transform: translateY(0); }
    }
    .animate-count {
      animation: countUp 0.8s ease forwards;
    }
    /* 响应式调整补充 */
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
      .section-title {
        font-size: 1.35rem;
      }
    }
    .bg-primary-dark {
      background-color: #1E3F52;
    }