/* roulang page: index */
:root {
      --primary-deep: #1A2B4C;
      --primary-dark: #152037;
      --accent-amber: #D49B3B;
      --accent-hover: #b8862b;
      --bg-light: #F8F9FA;
      --white: #FFFFFF;
      --text-dark: #1e293b;
      --text-gray: #475569;
      --text-muted: #64748b;
      --border-light: #e2e8f0;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-image: 16px;
      --transition: 0.25s ease;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    
    .container {
      max-width: var(--max-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    /* 导航栏固定顶部 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }
    
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-deep);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--accent-amber);
      margin-right: 6px;
      font-size: 24px;
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    
    .nav-links a {
      color: #333;
      font-weight: 500;
      font-size: 15px;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--accent-amber);
    }
    
    .nav-cta-mobile {
      display: none;
    }
    
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--primary-deep);
      padding: 8px;
    }
    
    /* 移动端导航面板 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--white);
      box-shadow: -5px 0 25px rgba(0,0,0,0.1);
      z-index: 1100;
      padding: 32px 24px;
      transition: right 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    .mobile-menu.active {
      right: 0;
    }
    .mobile-menu a {
      display: block;
      padding: 16px 8px;
      font-size: 18px;
      font-weight: 500;
      border-bottom: 1px solid var(--border-light);
      color: var(--text-dark);
    }
    .mobile-menu .close-btn {
      align-self: flex-end;
      background: none;
      border: none;
      font-size: 28px;
      margin-bottom: 24px;
      color: var(--primary-deep);
    }
    
    /* Hero 区域 */
    .hero {
      padding-top: calc(var(--nav-height) + 48px);
      padding-bottom: 80px;
      background-color: var(--bg-light);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: 42px;
      font-weight: 700;
      color: var(--primary-deep);
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .hero-left .subtitle {
      font-size: 18px;
      color: var(--text-gray);
      margin-bottom: 32px;
      line-height: 1.6;
      max-width: 480px;
    }
    .btn-primary {
      background: var(--primary-deep);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      display: inline-block;
      transition: background 0.2s, transform 0.1s;
      border: none;
      box-shadow: 0 4px 12px rgba(26,43,76,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
    }
    .hero-right {
      flex: 1;
    }
    .hero-right img {
      border-radius: var(--radius-image);
      box-shadow: var(--shadow-md);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    
    /* 板块通用间距 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 600;
      color: var(--primary-deep);
      margin-bottom: 16px;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 48px;
      font-size: 17px;
    }
    
    /* 服务卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      text-align: left;
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 42px;
      color: var(--accent-amber);
      margin-bottom: 24px;
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 14px;
      color: var(--primary-deep);
    }
    
    /* 数据统计条 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 38px;
      font-weight: 700;
      color: var(--accent-amber);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-gray);
      font-size: 16px;
    }
    
    /* 流程步骤 */
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 40px;
    }
    .step-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .step-number {
      font-size: 48px;
      font-weight: 700;
      color: rgba(26,43,76,0.08);
      position: absolute;
      top: 16px;
      right: 24px;
    }
    .step-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--primary-deep);
    }
    
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-card img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      border-radius: var(--radius-card) var(--radius-card) 0 0;
    }
    .case-content {
      padding: 24px;
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--primary-deep);
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      padding: 8px 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-gray);
      padding-right: 32px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--accent-amber);
      transition: transform 0.2s;
    }
    
    /* 最终 CTA 横幅 */
    .cta-banner {
      background: var(--primary-deep);
      border-radius: var(--radius-card);
      padding: 64px 48px;
      text-align: center;
      color: white;
      margin: 60px 0;
    }
    .btn-accent {
      background: var(--accent-amber);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: background 0.2s;
      border: none;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
    }
    
    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: #B0B8C5;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
    }
    .footer a:hover {
      color: var(--accent-amber);
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-left .subtitle {
        max-width: 100%;
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .hero-left h1 {
        font-size: 32px;
      }
      .cards-grid, .steps-grid, .stats-grid, .case-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .section {
        padding: 64px 0;
      }
      .container {
        padding-left: 20px;
        padding-right: 20px;
      }
    }