/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-hover: #154E63;
      --accent: #0D9488;
      --accent-hover: #0F766E;
      --bg: #F8FAFC;
      --white: #FFFFFF;
      --text: #1E293B;
      --text-secondary: #64748B;
      --border-light: #E2E8F0;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.03);
      --shadow-card-hover: 0 6px 24px rgba(26,95,122,0.08);
      --shadow-nav: 0 1px 8px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 767px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      z-index: 50;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.2s ease, border-color 0.2s ease;
    }
    .nav.scrolled {
      box-shadow: var(--shadow-nav);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      height: 100%;
    }
    .logo {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      gap: 36px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text);
      text-decoration: none;
      font-size: 16px;
      font-weight: 500;
      transition: color 0.2s ease;
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
      z-index: 55;
    }
    .hamburger span {
      display: block;
      width: 26px;
      height: 2.5px;
      background: var(--text);
      border-radius: 4px;
      transition: all 0.2s ease;
    }
    @media (max-width: 767px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        font-size: 22px;
      }
      .nav-links.mobile-open {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      body.menu-open {
        overflow: hidden;
      }
    }
    /* 板块间距 */
    .section {
      padding: 120px 0;
    }
    @media (max-width: 1024px) {
      .section {
        padding: 80px 0;
      }
    }
    @media (max-width: 767px) {
      .section {
        padding: 60px 0;
      }
    }
    h2 {
      font-size: 32px;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text);
      text-align: center;
    }
    h3 {
      font-size: 22px;
      font-weight: 600;
      line-height: 1.4;
      margin-bottom: 10px;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      margin-bottom: 48px;
      max-width: 680px;
      margin-left: auto;
      margin-right: auto;
    }
    /* 按钮 */
    .btn {
      display: inline-block;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
      text-decoration: none;
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
      cursor: pointer;
      border: none;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      padding: 14px 32px;
    }
    .btn-secondary:hover {
      background: var(--primary);
      color: white;
    }
    .btn-cta {
      background: var(--accent);
      color: white;
      padding: 16px 40px;
      font-size: 18px;
      border-radius: var(--radius-btn);
      box-shadow: 0 4px 10px rgba(13,148,136,0.15);
    }
    .btn-cta:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(13,148,136,0.2);
    }
    /* hero 数据卡片 */
    .data-card {
      background: #F1F5F9;
      border-radius: var(--radius-card);
      padding: 20px;
      text-align: center;
    }
    .data-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
    }
    /* 服务矩阵非对称 */
    .service-grid {
      display: grid;
      grid-template-columns: 7fr 5fr;
      gap: 24px;
      margin-top: 32px;
    }
    .service-large {
      background: var(--white);
      border-radius: 16px;
      padding: 28px;
      box-shadow: var(--shadow-card);
      display: flex;
      gap: 24px;
    }
    .service-large img {
      width: 240px;
      height: 150px;
      object-fit: cover;
      border-radius: 12px;
      background: #E2E8F0;
    }
    .service-small {
      background: var(--white);
      border-radius: 12px;
      padding: 22px;
      box-shadow: var(--shadow-card);
      border-left: 4px solid var(--primary);
      margin-bottom: 20px;
    }
    @media (max-width: 1024px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
      .service-large {
        flex-direction: column;
      }
      .service-large img {
        width: 100%;
        height: auto;
      }
    }
    /* 结果对比卡 */
    .compare-row {
      display: flex;
      gap: 32px;
      margin-top: 24px;
    }
    .compare-card {
      flex: 1;
      padding: 28px;
      border-radius: 16px;
    }
    .before {
      background: #F1F5F9;
    }
    .after {
      background: var(--white);
      border: 1px solid var(--primary);
      position: relative;
    }
    .improve-badge {
      position: absolute;
      right: 20px;
      top: -12px;
      background: var(--accent);
      color: white;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 14px;
    }
    @media (max-width: 767px) {
      .compare-row {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-item {
      background: var(--white);
      border-radius: 12px;
      margin-bottom: 12px;
      box-shadow: var(--shadow-card);
    }
    .faq-question {
      padding: 18px 24px;
      font-size: 18px;
      font-weight: 500;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: #F8FAFC;
      padding: 0 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 20px 24px;
    }
    /* 表单 */
    .contact-form {
      background: var(--white);
      border-radius: 16px;
      padding: 40px;
      max-width: 640px;
      margin: 32px auto;
      box-shadow: var(--shadow-card);
    }
    input, textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-light);
      border-radius: 8px;
      margin-bottom: 20px;
      font-family: inherit;
      transition: border 0.2s;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,122,0.1);
    }
    .trust-badges {
      display: flex;
      gap: 24px;
      justify-content: center;
      color: var(--text-secondary);
      font-size: 13px;
      margin-top: 24px;
    }
    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      text-align: center;
      padding: 60px 0 40px;
    }
    .footer-links a {
      color: #CBD5E1;
      margin: 0 16px;
      text-decoration: none;
    }