/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: rgba(78, 110, 242, 0.08);
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      
      --bg-page: #F5F6FA;
      --bg-white: #FFFFFF;
      --bg-subtle: #F0F2F5;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-placeholder: #C9CDD4;
      --border-light: #E5E8EF;
      
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.08);
      --shadow-button: 0 0 0 3px rgba(78, 110, 242, 0.2);
      
      --font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --container-max: 1200px;
      --header-height: 64px;
      --transition: 200ms ease;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-family);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      padding-top: var(--header-height);
    }
    
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    
    button, .btn {
      cursor: pointer;
      font-family: var(--font-family);
      font-weight: 500;
      border: none;
      outline: none;
      transition: all var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border-radius: var(--radius-sm);
      font-size: 16px;
      line-height: 1.2;
    }
    
    h1, h2, h3 {
      font-weight: 600;
      color: var(--text-primary);
    }
    
    h1 {
      font-size: 36px;
      line-height: 48px;
      font-weight: 700;
    }
    
    h2 {
      font-size: 28px;
      line-height: 40px;
      margin-bottom: 16px;
    }
    
    h3 {
      font-size: 20px;
      line-height: 28px;
      margin-bottom: 8px;
    }
    
    p {
      color: var(--text-secondary);
      font-size: 16px;
      line-height: 24px;
    }
    
    /* ----- 导航系统 (毛玻璃固定导航) ----- */
    header.nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--primary);
      font-size: 26px;
    }
    
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    
    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-primary);
      padding: 8px 0;
      position: relative;
      transition: color var(--transition);
    }
    
    .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 var(--transition);
    }
    
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    
    .menu-toggle {
      display: none;
      background: transparent;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      padding: 4px;
    }
    
    /* 移动端导航抽屉 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        box-shadow: var(--shadow-card);
        transform: translateY(-120%);
        opacity: 0;
        transition: transform 0.3s ease, opacity 0.2s ease;
        border-bottom: 1px solid var(--border-light);
        z-index: 999;
      }
      .nav-links.active {
        transform: translateY(0);
        opacity: 1;
      }
      .menu-toggle {
        display: block;
      }
    }
    
    /* ----- 通用区块样式 ----- */
    section {
      padding: 80px 0;
    }
    
    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-header h2 {
      margin-bottom: 12px;
    }
    .section-header p {
      max-width: 640px;
      margin: 0 auto;
      color: var(--text-secondary);
    }
    
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      transition: box-shadow var(--transition), transform var(--transition);
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    
    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-primary:focus-visible {
      box-shadow: var(--shadow-button);
    }
    
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--text-placeholder);
      color: var(--text-primary);
      padding: 12px 28px;
      border-radius: var(--radius-sm);
    }
    .btn-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: var(--bg-subtle);
    }
    
    /* 图标容器 */
    .icon-circle {
      width: 56px;
      height: 56px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 26px;
    }
    
    /* Hero 区域 */
    .hero {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-repeat: no-repeat;
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      padding: 60px 48px;
      margin: 20px 0 0;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(245, 246, 250, 0.75);
      backdrop-filter: blur(2px);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 560px;
    }
    .hero-content h1 {
      margin-bottom: 20px;
    }
    .hero-content p {
      font-size: 18px;
      margin-bottom: 32px;
    }
    .hero-visual {
      position: relative;
      z-index: 2;
      width: 45%;
    }
    .hero-visual img {
      border-radius: 16px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.12);
    }
    
    /* 服务卡片图片 */
    .service-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 20px;
    }
    
    /* 流程步骤 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }
    .step-item {
      text-align: center;
      flex: 1;
      position: relative;
    }
    .step-number {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: 700;
      margin: 0 auto 16px;
    }
    
    /* 数据展示 */
    .data-highlight {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 18px;
      cursor: pointer;
      background: transparent;
      width: 100%;
      border: none;
      text-align: left;
      color: var(--text-primary);
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    
    /* CTA 通栏 */
    .cta-strip {
      background: linear-gradient(105deg, rgba(78,110,242,0.08) 0%, rgba(255,255,255,1) 80%);
      border-radius: var(--radius-lg);
      text-align: center;
      padding: 64px 24px;
    }
    
    /* 页脚 */
    footer {
      background: #1F2329;
      color: white;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      color: var(--text-secondary);
      font-size: 14px;
    }
    
    /* 响应式调整 */
    @media (max-width: 1024px) {
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .hero { flex-direction: column; text-align: center; padding: 48px 24px; }
      .hero-visual { width: 80%; margin-top: 24px; }
    }
    @media (max-width: 768px) {
      section { padding: 60px 0; }
      .container { padding: 0 16px; }
      .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
      .process-steps { flex-direction: column; gap: 32px; }
      .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 28px; line-height: 38px; }
    }