/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary: #1A5FDC;
      --primary-light: #E8F0FE;
      --secondary: #FF6B35;
      --secondary-light: #FFF0EA;
      --bg: #F8FAFC;
      --surface: #FFFFFF;
      --text-main: #1E293B;
      --text-soft: #64748B;
      --text-muted: #94A3B8;
      --border: #E2E8F0;
      --success: #10B981;
      --danger: #EF4444;
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-md: 0 10px 25px rgba(26,95,220,0.12), 0 4px 10px rgba(0,0,0,0.05);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "Segoe UI", system-ui, sans-serif;
      --nav-width: 240px;
      --header-height: 56px;
      --transition: all 0.2s ease;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    
    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* ----- 桌面端左侧竖向导航 ----- */
    .desktop-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background: var(--surface);
      box-shadow: 1px 0 12px rgba(0,0,0,0.04);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      z-index: 1000;
      padding: 32px 20px 24px;
    }
    
    .brand {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 48px;
    }
    
    .brand-logo {
      width: 40px;
      height: 40px;
      background: linear-gradient(135deg, var(--primary) 0%, #3B82F6 100%);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 22px;
    }
    
    .brand-text {
      font-weight: 700;
      font-size: 20px;
      color: var(--text-main);
      letter-spacing: -0.3px;
    }
    
    .nav-links {
      display: flex;
      flex-direction: column;
      gap: 8px;
      flex: 1;
    }
    
    .nav-item {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 12px 16px;
      border-radius: 10px;
      color: var(--text-soft);
      font-weight: 500;
      position: relative;
      transition: var(--transition);
    }
    
    .nav-item i {
      width: 20px;
      font-size: 18px;
      text-align: center;
    }
    
    .nav-item:hover {
      background-color: var(--primary-light);
      color: var(--primary);
    }
    
    .nav-item.active {
      background-color: var(--primary-light);
      color: var(--primary);
      font-weight: 600;
    }
    
    .nav-item.active::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      bottom: 8px;
      width: 3px;
      background: var(--primary);
      border-radius: 0 4px 4px 0;
    }
    
    .nav-footer {
      margin-top: auto;
      color: var(--text-muted);
      font-size: 13px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    
    .social-icons {
      display: flex;
      gap: 16px;
      font-size: 18px;
    }
    
    .social-icons a:hover {
      color: var(--primary);
    }
    
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: var(--surface);
      border-bottom: 1px solid var(--border);
      padding: 0 20px;
      justify-content: space-between;
      align-items: center;
      z-index: 999;
    }
    
    .mobile-brand {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    
    .mobile-logo {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .hamburger {
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
    }
    
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--surface);
      z-index: 1001;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
    }
    
    .mobile-menu.open {
      display: flex;
    }
    
    .close-menu {
      position: absolute;
      top: 20px;
      right: 20px;
      background: none;
      border: none;
      font-size: 28px;
      cursor: pointer;
    }
    
    .mobile-menu a {
      font-size: 24px;
      font-weight: 600;
      color: var(--text-main);
    }
    
    /* 主内容区域（为左侧导航留出空间） */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
    }
    
    /* 通用板块样式 */
    section {
      padding: 100px 0;
    }
    
    .section-title {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }
    
    .section-subtitle {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 48px;
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      background: linear-gradient(135deg, #F8FAFC 0%, #E8F0FE 100%);
      position: relative;
      overflow: hidden;
      min-height: 90vh;
      display: flex;
      align-items: center;
    }
    
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    
    .hero h1 span {
      color: var(--secondary);
      border-bottom: 3px solid var(--secondary);
    }
    
    .hero p {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 32px;
    }
    
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .btn-primary {
      background: var(--secondary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      box-shadow: 0 4px 12px rgba(255,107,53,0.3);
    }
    
    .btn-primary:hover {
      background: #E55A2B;
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
    }
    
    .btn-outline:hover {
      background: var(--primary-light);
    }
    
    .hero-image {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      height: 400px;
      box-shadow: var(--shadow-md);
      position: relative;
    }
    
    /* 仪表板卡片 */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    
    .stat-card {
      background: var(--surface);
      padding: 28px 20px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
    }
    
    .stat-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    
    .stat-number {
      font-family: var(--font-number);
      font-size: 40px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    
    .stat-label {
      color: var(--text-soft);
      margin-top: 8px;
      font-weight: 500;
    }
    
    /* 服务矩阵 错落栅格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    
    .service-card {
      background: var(--surface);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid transparent;
      position: relative;
    }
    
    .service-card:nth-child(2) {
      grid-column: span 1;
    }
    
    @media (min-width: 769px) {
      .service-card:nth-child(3) {
        grid-column: span 2;
        display: flex;
        gap: 32px;
        align-items: center;
      }
      .service-card:nth-child(3) .service-img {
        width: 160px;
        height: 120px;
        flex-shrink: 0;
        border-radius: 12px;
        background-image: url('/assets/images/coverpic/cover-2.webp');
        background-size: cover;
      }
    }
    
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary);
    }
    
    .service-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 20px;
    }
    
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    
    /* 对比板块 */
    .comparison-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      align-items: start;
    }
    
    .compare-card {
      background: var(--surface);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    
    .compare-card.old {
      background: #F1F5F9;
      border: 1px solid #CBD5E1;
      color: var(--text-soft);
    }
    
    .compare-card.new {
      background: var(--primary-light);
      border: 2px solid var(--primary);
      color: var(--text-main);
    }
    
    .compare-item {
      display: flex;
      justify-content: space-between;
      padding: 12px 0;
      border-bottom: 1px solid var(--border);
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }
    
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--text-main);
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-soft);
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    
    /* 表单 */
    .contact-form {
      background: var(--surface);
      padding: 40px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-md);
      max-width: 600px;
      margin: 0 auto;
    }
    
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 14px 16px;
      border: 1px solid #CBD5E1;
      border-radius: var(--radius-input);
      margin-bottom: 16px;
      transition: var(--transition);
    }
    
    .form-group input:focus, .form-group textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,220,0.2);
    }
    
    /* 页脚 */
    .footer {
      background: #F1F5F9;
      padding: 32px 0;
      color: var(--text-soft);
    }
    
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .desktop-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: var(--header-height);
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .dashboard-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    
    @media (max-width: 768px) {
      .section-title {
        font-size: 28px;
      }
      .hero h1 {
        font-size: 32px;
      }
      .comparison-wrapper {
        grid-template-columns: 1fr;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .service-card:nth-child(3) {
        grid-column: span 1;
        flex-direction: column;
      }
    }