/* roulang page: index */
:root {
      --color-primary: #0F4C81;
      --color-primary-hover: #0B3D6B;
      --color-accent: #FF6B35;
      --color-bg: #F8FAFC;
      --color-card: #FFFFFF;
      --color-text: #1E293B;
      --color-text-soft: #64748B;
      --radius-card: 16px;
      --radius-btn: 12px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --transition: 0.3s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      margin: 0;
      background-color: #F8FAFC;
      color: #1E293B;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航 */
    .nav-blur {
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid rgba(0,0,0,0.05);
      transition: box-shadow 0.3s ease;
    }
    .nav-shadow {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav-link {
      color: #1E293B;
      font-weight: 500;
      transition: color 0.3s;
      text-decoration: none;
    }
    .nav-link:hover {
      color: #0F4C81;
    }
    .btn-primary {
      background-color: #0F4C81;
      color: white;
      border-radius: 12px;
      padding: 10px 24px;
      font-weight: 600;
      transition: background-color 0.3s, transform 0.2s;
      display: inline-block;
      text-decoration: none;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: #0B3D6B;
      transform: translateY(-1px);
    }
    .btn-outline {
      border: 2px solid #0F4C81;
      color: #0F4C81;
      background: transparent;
      border-radius: 12px;
      padding: 10px 24px;
      font-weight: 600;
      transition: background-color 0.3s, color 0.3s, transform 0.2s;
      display: inline-block;
      text-decoration: none;
      cursor: pointer;
    }
    .btn-outline:hover {
      background-color: rgba(15,76,129,0.08);
      transform: translateY(-1px);
    }
    .card-hover {
      transition: box-shadow 0.3s, transform 0.3s;
    }
    .card-hover:hover {
      box-shadow: 0 8px 30px rgba(0,0,0,0.08);
      transform: translateY(-2px);
    }
    /* 汉堡菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: white;
      z-index: 100;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      font-size: 20px;
    }
    .mobile-menu.active {
      display: flex;
    }
    .close-btn {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      font-size: 28px;
      cursor: pointer;
      color: #1E293B;
    }
    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid #E2E8F0;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      padding: 16px 0;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: #1E293B;
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: #0F4C81;
    }
    .faq-icon {
      transition: transform 0.3s;
      font-size: 20px;
      color: #64748B;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: #475569;
      padding: 0 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0 0 16px 0;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
      color: #0F4C81;
    }
    /* 动态装饰 */
    .hero-curve {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      overflow: hidden;
      line-height: 0;
      z-index: 0;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }
    @media (min-width: 769px) {
      .hamburger {
        display: none;
      }
    }
    .hamburger {
      background: none;
      border: none;
      font-size: 28px;
      cursor: pointer;
      color: #1E293B;
      padding: 8px;
    }