/* roulang page: index */
/* ===== 设计变量与全局重置 ===== */
    :root {
      --primary-start: #4E6EF2;
      --primary-end: #7B5CFA;
      --primary-solid: #4E6EF2;
      --primary-light: rgba(78, 110, 242, 0.08);
      --gradient-main: linear-gradient(135deg, #4E6EF2 0%, #7B5CFA 100%);
      
      --success: #00B578;
      --success-light: rgba(0, 181, 120, 0.08);
      --warning: #FF9F0A;
      --warning-light: rgba(255, 159, 10, 0.08);
      --error: #FA5151;
      
      --bg-base: #F5F6FA;
      --card-white: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E8ECF1;
      
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 20px;
      --radius-input: 8px;
      
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 24px rgba(0,0,0,0.08);
      --shadow-nav: 0 1px 4px rgba(0,0,0,0.04);
      
      --font-sans: 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      
      --transition-fast: 150ms ease;
      --transition-smooth: 200ms ease;
      
      --section-padding-y: 80px;
      --container-padding-x: 24px;
      --column-gap: 24px;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.5;
      color: var(--text-primary);
      background-color: var(--bg-base);
      -webkit-font-smoothing: antialiased;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-fast);
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, input, textarea {
      font-family: inherit;
      outline: none;
    }
    
    /* 容器 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: var(--container-padding-x);
      padding-right: var(--container-padding-x);
    }
    
    /* 渐变文字工具类 */
    .text-gradient {
      background: var(--gradient-main);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    
    /* 按钮体系 */
    .btn-primary {
      background: var(--gradient-main);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
      transition: all var(--transition-smooth);
      box-shadow: 0 2px 8px rgba(78, 110, 242, 0.2);
      white-space: nowrap;
    }
    
    .btn-primary:hover {
      filter: brightness(1.05);
      box-shadow: 0 6px 16px rgba(78, 110, 242, 0.3);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      color: var(--primary-solid);
      border: 1.5px solid var(--primary-solid);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all var(--transition-smooth);
      white-space: nowrap;
    }
    
    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary-end);
      color: var(--primary-end);
      transform: translateY(-1px);
    }
    
    /* 卡片悬停效果 */
    .card-hover {
      transition: all var(--transition-smooth);
    }
    
    .card-hover:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    
    /* 输入框 */
    .input-field {
      width: 100%;
      padding: 12px 16px;
      background: var(--bg-base);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      font-size: 14px;
      color: var(--text-primary);
      transition: all var(--transition-fast);
    }
    
    .input-field:focus {
      border-color: var(--primary-solid);
      box-shadow: 0 0 0 3px rgba(78, 110, 242, 0.2);
    }
    
    /* 数据徽章 */
    .badge-capsule {
      display: inline-flex;
      align-items: center;
      padding: 6px 14px;
      border-radius: var(--radius-badge);
      font-size: 14px;
      font-weight: 500;
      background: var(--primary-light);
      color: var(--primary-solid);
      white-space: nowrap;
    }
    
    .badge-capsule.green {
      background: var(--success-light);
      color: var(--success);
    }
    
    .badge-capsule.orange {
      background: var(--warning-light);
      color: var(--warning);
    }
    
    .badge-number {
      font-weight: 700;
      font-size: 24px;
      margin-right: 4px;
    }
    
    /* 板块标题 */
    .section-title {
      font-size: 28px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 16px;
      text-align: center;
    }
    
    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 640px;
      margin: 0 auto 48px;
    }
    
    /* 导航样式 */
    .header {
      background: white;
      height: 64px;
      display: flex;
      align-items: center;
      box-shadow: var(--shadow-nav);
      position: sticky;
      top: 0;
      z-index: 100;
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      font-size: 20px;
      font-weight: 700;
      display: flex;
      align-items: center;
    }
    
    .logo .brand-highlight {
      background: var(--gradient-main);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    
    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
      font-size: 14px;
      color: var(--text-primary);
    }
    
    .nav-menu a {
      position: relative;
      padding: 4px 0;
    }
    
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary-solid);
    }
    
    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary-solid);
    }
    
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      cursor: pointer;
    }
    
    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 280px;
      height: 100vh;
      background: white;
      box-shadow: -4px 0 20px rgba(0,0,0,0.1);
      transition: right 0.3s ease;
      z-index: 200;
      padding: 24px;
      display: flex;
      flex-direction: column;
    }
    
    .mobile-menu.open {
      right: 0;
    }
    
    .mobile-menu a {
      display: block;
      padding: 16px 0;
      font-size: 18px;
      border-bottom: 1px solid var(--border-light);
      color: var(--text-primary);
    }
    
    .mobile-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.3);
      z-index: 150;
      display: none;
    }
    
    .mobile-overlay.show {
      display: block;
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      margin-bottom: 12px;
      cursor: pointer;
      transition: all var(--transition-fast);
      box-shadow: var(--shadow-card);
    }
    
    .faq-question {
      display: flex;
      align-items: center;
      gap: 16px;
      font-weight: 500;
      font-size: 16px;
    }
    
    .faq-q {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary-solid);
      min-width: 32px;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 150ms ease;
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 12px;
      padding-left: 48px;
    }
    
    .faq-item.open .faq-answer {
      max-height: 200px;
    }
    
    /* Footer */
    .footer {
      background: #F5F6FA;
      padding: 60px 0 24px;
      color: var(--text-primary);
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    
    .footer a {
      color: var(--text-secondary);
      font-size: 14px;
      transition: color var(--transition-fast);
    }
    
    .footer a:hover {
      color: var(--primary-solid);
    }
    
    .copyright {
      text-align: center;
      font-size: 12px;
      color: var(--text-secondary);
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid var(--border-light);
    }
    
    /* 响应式断点 */
    @media (max-width: 1024px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .case-grid {
        columns: 2 !important;
      }
    }
    
    @media (max-width: 768px) {
      :root {
        --section-padding-y: 48px;
      }
      
      .nav-menu, .header .btn-primary {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      
      .hero-wrapper {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        width: 100% !important;
      }
      
      .features-grid {
        grid-template-columns: 1fr !important;
      }
      
      .case-grid {
        columns: 1 !important;
      }
      
      .solution-compare {
        flex-direction: column;
      }
      .solution-divider {
        display: none;
      }
      
      .contact-card {
        flex-direction: column;
      }
      
      .footer-grid {
        grid-template-columns: 1fr;
      }
      
      .section-title {
        font-size: 22px;
      }
      h1 {
        font-size: 32px !important;
        line-height: 1.3 !important;
      }
    }
    
    @media (max-width: 520px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }