/* roulang page: index */
:root {
      --primary: #2B5F8A;
      --accent: #C87E4F;
      --soft: #E8F1F8;
      --dark: #1E2A38;
      --graytext: #4A5568;
      --card: #F7FAFC;
      --border: #CBD5E0;
      --white: #FFFFFF;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
      background-color: var(--white);
      color: var(--graytext);
      line-height: 1.7;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .section-padding {
      padding: 96px 0;
    }
    @media (max-width: 1023px) {
      .section-padding {
        padding: 72px 0;
      }
    }
    @media (max-width: 639px) {
      .section-padding {
        padding: 56px 0;
      }
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.88);
      backdrop-filter: blur(8px);
      transition: background 0.3s ease, box-shadow 0.3s ease;
    }
    .navbar.scrolled {
      background: #FFFFFF;
      box-shadow: 0 1px 4px rgba(0,0,0,0.05);
    }
    .nav-link {
      font-weight: 500;
      color: #4A5568;
      padding: 8px 4px;
      margin: 0 12px;
      position: relative;
      white-space: nowrap;
    }
    .nav-link:hover {
      color: #2B5F8A;
    }
    .nav-link.active {
      color: #2B5F8A;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: #C87E4F;
      border-radius: 2px;
    }
    .btn-primary {
      background: #C87E4F;
      color: white;
      font-weight: 600;
      font-size: 14px;
      padding: 10px 24px;
      border-radius: 8px;
      border: none;
      cursor: pointer;
      transition: background 0.25s ease, transform 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #B56A3D;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid #2B5F8A;
      color: #2B5F8A;
      font-weight: 600;
      font-size: 14px;
      padding: 10px 24px;
      border-radius: 8px;
      transition: background 0.25s ease;
      display: inline-block;
    }
    .btn-outline:hover {
      background: #E8F1F8;
    }
    .card {
      background: #F7FAFC;
      border-radius: 12px;
      padding: 28px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
      transition: all 0.25s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    }
    .data-number {
      font-weight: 700;
      font-size: 42px;
      line-height: 1.2;
      color: #2B5F8A;
    }
    .accent-number {
      color: #C87E4F;
    }
    .faq-item {
      border-bottom: 1px solid #CBD5E0;
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      color: #1E2A38;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      background: #F7FAFC;
      border-radius: 8px;
      margin-top: 4px;
      color: #4A5568;
      font-size: 14px;
      line-height: 1.6;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px;
      margin-top: 8px;
    }
    .hamburger-menu {
      display: none;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger-menu {
        display: block;
      }
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: #2B5F8A;
      background: #F7FAFC;
      box-shadow: 0 0 0 2px rgba(43,95,138,0.15);
    }