/* roulang page: index */
:root {
      --primary-green: #0F7B4E;
      --deep-green: #0A5F3A;
      --accent-orange: #F59E0B;
      --deep-orange: #D97706;
      --charcoal: #1E293B;
      --gray-blue: #F0F4F8;
      --soft-white: #FFFFFF;
      --border-light: #E2E8F0;
      --text-muted: #64748B;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.06);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.1);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: #FFFFFF;
      color: #1E293B;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
      outline: none;
    }

    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 导航固定 */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: #FFFFFF;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .logo-text {
      font-weight: 700;
      font-size: 22px;
      color: var(--primary-green);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .nav-link {
      color: #475569;
      font-weight: 500;
      font-size: 16px;
      padding: 0 12px;
      position: relative;
      transition: var(--transition);
      white-space: nowrap;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary-green);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--primary-green);
      transition: width 0.2s ease;
    }

    .nav-link:hover::after,
    .nav-link.active::after {
      width: 70%;
    }

    .search-box {
      background: #F8FAFC;
      border: 1px solid var(--border-light);
      border-radius: 20px;
      padding: 8px 16px;
      font-size: 14px;
      width: 180px;
      transition: var(--transition);
    }

    .search-box:focus {
      border-color: var(--primary-green);
      box-shadow: 0 0 0 2px rgba(15,123,78,0.15);
    }

    .btn-primary {
      background: var(--primary-green);
      color: white;
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: var(--deep-green);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-green);
      color: var(--primary-green);
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
    }

    .btn-outline:hover {
      background: var(--primary-green);
      color: white;
    }

    .btn-accent {
      background: var(--accent-orange);
      color: white;
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
      border: none;
      cursor: pointer;
    }

    .btn-accent:hover {
      background: var(--deep-orange);
    }

    /* 卡片通用 */
    .card {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-2px);
    }

    /* Hero overlay */
    .hero-overlay {
      background: linear-gradient(90deg, rgba(0,0,0,0.7) 0%, rgba(15,123,78,0.5) 100%);
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      cursor: pointer;
      padding: 18px 16px;
      background: #FAFAFA;
      font-weight: 500;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: background 0.2s;
    }

    .faq-question:hover {
      background: #EDF7F2;
    }

    .faq-answer {
      padding: 0 16px 18px;
      color: #475569;
      display: none;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    .faq-item.active .faq-question {
      background: #EDF7F2;
      color: var(--primary-green);
    }

    /* 移动端汉堡菜单 */
    .mobile-menu {
      display: none;
    }

    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu {
        display: flex;
        align-items: center;
      }
      .search-box {
        width: 140px;
      }
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
      .hero-title {
        font-size: 36px !important;
      }
      .grid-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-services {
        grid-template-columns: 1fr;
      }
      .comparison-container {
        flex-direction: column;
      }
    }

    @media (max-width: 520px) {
      .hero-title {
        font-size: 28px !important;
      }
      .btn-group {
        flex-direction: column;
        gap: 12px;
      }
    }