/* roulang page: index */
:root {
      --primary: #0A6EBD;
      --primary-dark: #085C9E;
      --secondary: #F59E0B;
      --secondary-light: #FDE68A;
      --bg-page: #F8FAFC;
      --bg-white: #FFFFFF;
      --bg-light: #F1F5F9;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --text-on-dark: #FFFFFF;
      --border-light: #E2E8F0;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 50px;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(10,110,189,0.12);
      --transition: 0.3s ease;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-stack);
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 排版 */
    h1, h2, h3, .h2, .h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    h1 { font-size: 48px; }
    h2 { font-size: 36px; }
    h3 { font-size: 24px; }
    p { margin-bottom: 1rem; color: var(--text-muted); }
    a { text-decoration: none; color: inherit; transition: color 0.2s; }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-xl);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
      min-height: 48px;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      border-color: var(--primary-dark);
      transform: scale(1.03);
      box-shadow: 0 6px 16px rgba(10,110,189,0.4);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background: rgba(10,110,189,0.08);
      transform: scale(1.02);
    }
    .btn-light {
      background: white;
      color: var(--primary);
      border-color: white;
    }
    .btn-light:hover {
      background: #f0f9ff;
    }
    
    /* 导航 */
    .site-header {
      background: white;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      height: var(--nav-height);
      position: sticky;
      top: 0;
      z-index: 50;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      font-size: 28px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 3px solid transparent;
      transition: 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text-main);
      cursor: pointer;
    }
    
    /* Hero */
    .hero {
      background: linear-gradient(270deg, rgba(10,110,189,0.75) 0%, rgba(0,32,63,0.8) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 85vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
    }
    .hero-content {
      max-width: 700px;
    }
    .hero h1 {
      font-weight: 800;
      margin-bottom: 1.5rem;
      text-shadow: 0 4px 12px rgba(0,0,0,0.3);
    }
    .hero .subtitle {
      font-size: 20px;
      font-weight: 400;
      opacity: 0.9;
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    .section-head {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-head h2 {
      margin-bottom: 12px;
      color: var(--text-main);
    }
    
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: white;
      padding: 32px 24px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: all var(--transition);
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 40px;
      margin-bottom: 20px;
      color: var(--primary);
    }
    
    /* 服务项目 左右交替 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .service-text {
      flex: 1;
    }
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap 0.2s;
    }
    .text-link:hover { gap: 8px; }
    
    /* 数据看板 */
    .stats-bg {
      background: #EFF6FF;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--secondary);
      line-height: 1.2;
    }
    .stat-label {
      font-size: 16px;
      color: var(--text-muted);
      margin-top: 8px;
    }
    
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 200px;
      object-fit: cover;
      transition: transform 0.4s;
    }
    .case-card:hover .case-img {
      transform: scale(1.04);
    }
    .case-body {
      padding: 20px;
    }
    .tag {
      background: var(--secondary-light);
      color: #92400E;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      display: inline-block;
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      background: white;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
      border-left: 4px solid var(--primary);
    }
    .faq-answer {
      padding: 0 24px 20px;
      background: #F8FAFC;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    
    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #0A6EBD 0%, #085C9E 100%);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    
    /* 页脚 */
    .site-footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 800;
      color: white;
      margin-bottom: 12px;
    }
    .footer-links a {
      display: block;
      margin-bottom: 8px;
      color: #CBD5E1;
    }
    .footer-links a:hover { color: var(--secondary); }
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: #94A3B8;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      h2 { font-size: 30px; }
      .features-grid, .cases-grid { grid-template-columns: repeat(2,1fr); }
      .service-row { flex-direction: column; gap: 24px; }
      .service-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-menu-toggle { display: block; }
      .nav-links.mobile-open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: white;
        padding: 24px;
        box-shadow: 0 12px 24px rgba(0,0,0,0.1);
        gap: 16px;
      }
      h1 { font-size: 34px; }
      h2 { font-size: 28px; }
      .hero { min-height: 70vh; }
      .features-grid, .stats-grid, .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .section { padding: 56px 0; }
    }