/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #0A66FF;
      --primary-dark: #0852CC;
      --secondary: #FF6B2B;
      --secondary-dark: #E55A1C;
      --bg-page: #FAFBFC;
      --bg-card: #FFFFFF;
      --bg-dark: #111827;
      --text-main: #1F2937;
      --text-secondary: #4B5563;
      --text-weak: #6B7280;
      --text-light: #9CA3AF;
      --border-light: #E5E7EB;
      --radius-sm: 12px;
      --radius-md: 16px;
      --radius-lg: 20px;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 24px rgba(10,102,255,0.08);
      --max-width: 1280px;
      --header-height: 72px;
      --section-gap: 120px;
      --section-gap-mobile: 80px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.5;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }
    
    @media (max-width: 768px) {
      .container {
        padding: 0 24px;
      }
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: all 0.25s ease;
    }
    
    input {
      font-family: inherit;
      outline: none;
    }
    
    /* 通用标题 */
    h1, h2, h3, h4 {
      font-weight: 600;
      letter-spacing: -0.02em;
    }
    
    h2 {
      font-size: 36px;
      line-height: 1.25;
      margin-bottom: 16px;
    }
    
    h3 {
      font-size: 24px;
      line-height: 1.35;
    }
    
    /* ----- 导航 Header ----- */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: #FFFFFF;
      height: var(--header-height);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      display: flex;
      align-items: center;
    }
    
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--text-main);
    }
    
    .logo-icon {
      font-size: 28px;
      color: var(--primary);
      display: flex;
      align-items: center;
    }
    
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      font-size: 16px;
      color: #374151;
    }
    
    .nav-links a {
      position: relative;
      padding: 8px 0;
    }
    
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s;
    }
    
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    
    .header-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }
    
    .search-box {
      display: flex;
      align-items: center;
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: 20px;
      padding: 8px 18px;
      gap: 8px;
    }
    
    .search-box i {
      color: var(--text-weak);
      font-size: 14px;
    }
    
    .search-box input {
      border: none;
      background: transparent;
      font-size: 14px;
      width: 140px;
    }
    
    .btn-cta-nav {
      background: var(--secondary);
      color: white;
      border-radius: 20px;
      padding: 10px 22px;
      font-weight: 600;
      font-size: 15px;
      white-space: nowrap;
    }
    
    .btn-cta-nav:hover {
      background: var(--secondary-dark);
      transform: translateY(-1px);
    }
    
    .mobile-menu-btn {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--text-main);
    }
    
    /* ----- 按钮系统 ----- */
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-sm);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      display: inline-block;
      text-align: center;
    }
    
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 8px 16px rgba(10,102,255,0.15);
    }
    
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-sm);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      display: inline-block;
    }
    
    .btn-secondary:hover {
      background: rgba(10,102,255,0.04);
    }
    
    .btn-large {
      padding: 18px 44px;
      font-size: 17px;
      border-radius: var(--radius-lg);
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      padding: 100px 0 120px;
      display: flex;
      align-items: center;
      min-height: 600px;
    }
    
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(10,102,255,0.85) 0%, rgba(17,24,39,0.9) 100%);
    }
    
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      color: white;
    }
    
    .hero h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      margin-bottom: 20px;
    }
    
    .hero-sub {
      font-size: 20px;
      line-height: 1.6;
      opacity: 0.9;
      margin-bottom: 36px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }
    
    .hero .btn-primary {
      background: var(--secondary);
      border: none;
    }
    .hero .btn-primary:hover { background: var(--secondary-dark); }
    
    .hero .btn-secondary {
      border-color: white;
      color: white;
    }
    .hero .btn-secondary:hover { background: rgba(255,255,255,0.1); }
    
    .trust-badges {
      display: flex;
      gap: 40px;
      flex-wrap: wrap;
      opacity: 0.9;
      font-weight: 500;
    }
    
    .trust-badges span {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    
    /* ----- 通用区块 ----- */
    .section {
      padding: var(--section-gap) 0;
    }
    
    .section-header {
      text-align: center;
      margin-bottom: 56px;
    }
    
    .section-header p {
      color: var(--text-weak);
      font-size: 18px;
      max-width: 600px;
      margin: 0 auto;
    }
    
    /* 核心优势 2x2 网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    
    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      display: flex;
      gap: 24px;
      align-items: flex-start;
    }
    
    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    
    .feature-icon {
      font-size: 32px;
      color: var(--primary);
      width: 60px;
      height: 60px;
      background: rgba(10,102,255,0.08);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }
    
    .feature-text h3 {
      margin-bottom: 8px;
      font-size: 22px;
    }
    
    .feature-text p {
      color: var(--text-weak);
      line-height: 1.6;
    }
    
    /* 解决方案三列卡片 */
    .solutions-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    
    .solution-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    
    .solution-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    
    .solution-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    
    .solution-body {
      padding: 28px 24px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    
    .solution-body h3 {
      margin-bottom: 12px;
    }
    
    .solution-body p {
      color: var(--text-weak);
      margin-bottom: 20px;
      flex: 1;
    }
    
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .text-link:hover { text-decoration: underline; }
    
    /* 场景图文交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 80px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      background: #f0f2f5;
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h2 {
      margin-bottom: 16px;
    }
    
    /* 成功案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .case-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 28px;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .case-card:hover { box-shadow: var(--shadow-hover); }
    .case-logo {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .case-stats {
      font-weight: 700;
      font-size: 24px;
      color: var(--secondary);
      margin: 12px 0 8px;
    }
    .tag {
      background: #f3f4f6;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      color: var(--text-secondary);
      display: inline-block;
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
      background: white;
      transition: 0.2s;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      cursor: pointer;
      background: none;
      width: 100%;
      text-align: left;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-weak);
      display: none;
    }
    .faq-item.active .faq-answer { display: block; }
    .faq-item.active { background: #F9FAFB; }
    
    /* CTA横幅 */
    .cta-banner {
      background: var(--bg-dark);
      color: white;
      text-align: center;
      padding: 80px 0;
      border-radius: 32px;
      margin: 40px 0;
      background-image: radial-gradient(circle at 20% 30%, #1e3a5f, #111827);
    }
    
    /* 页脚 */
    .site-footer {
      background: #111827;
      color: #9CA3AF;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-col h4 {
      color: white;
      margin-bottom: 20px;
      font-size: 18px;
    }
    .footer-col a {
      display: block;
      margin-bottom: 12px;
      color: #9CA3AF;
    }
    .footer-col a:hover { color: var(--primary); }
    .copyright {
      border-top: 1px solid #1f2937;
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .nav-links, .header-actions .search-box { display: none; }
      .mobile-menu-btn { display: block; }
      .features-grid { grid-template-columns: 1fr; }
      .solutions-grid, .cases-grid { grid-template-columns: repeat(2,1fr); }
      .scenario-row { flex-direction: column; gap: 32px; }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .hero h1 { font-size: 36px; }
      .solutions-grid, .cases-grid { grid-template-columns: 1fr; }
      .hero-buttons .btn { width: 100%; }
      .footer-grid { grid-template-columns: 1fr; }
    }