:root {
      --primary: #1d4ed8;
      --primary-hover: #1e40af;
      --accent: #0284c7;
      --accent-warm: #f97316;
      --bg-page: #f8fafc;
      --bg-surface: #ffffff;
      --bg-subtle: #f1f5f9;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --border-color: #e2e8f0;
      --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05);
      --card-shadow-hover: 0 12px 28px -4px rgba(15, 23, 42, 0.1);
      --container-max: 1200px;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: all 0.25s ease;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }
    ul, ol {
      list-style: none;
    }
    .site-container {
      max-width: var(--container-max);
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
      width: 100%;
    }
    .section-wrap {
      padding: 70px 0;
      border-bottom: 1px solid var(--border-color);
    }
    .section-header {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 40px auto;
    }
    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      background: #e0f2fe;
      color: #0369a1;
      font-size: 0.85rem;
      font-weight: 600;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
      letter-spacing: -0.02em;
    }
    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
    }
    
    /* 顶部导航 */
    .site-nav-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-color);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .ai-page-logo {
      height: 38px;
      width: auto;
      display: block;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }
    .nav-link-item {
      display: inline-block;
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: var(--radius-sm);
    }
    .nav-link-item:hover, .nav-link-item.active {
      color: var(--primary);
      background: var(--bg-subtle);
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .nav-toggle-btn {
      display: none;
      background: none;
      border: 1px solid var(--border-color);
      padding: 6px 10px;
      border-radius: var(--radius-sm);
      cursor: pointer;
    }
    .nav-toggle-icon {
      display: block;
      width: 20px;
      height: 2px;
      background: var(--text-main);
      position: relative;
    }
    .nav-toggle-icon::before,
    .nav-toggle-icon::after {
      content: "";
      position: absolute;
      width: 20px;
      height: 2px;
      background: var(--text-main);
      left: 0;
    }
    .nav-toggle-icon::before { top: -6px; }
    .nav-toggle-icon::after { bottom: -6px; }

    /* 通用按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: var(--transition);
      border: 1px solid transparent;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(29, 78, 216, 0.25);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 16px rgba(29, 78, 216, 0.35);
      color: #ffffff;
    }
    .btn-secondary {
      background: #eff6ff;
      color: var(--primary);
      border-color: #bfdbfe;
    }
    .btn-secondary:hover {
      background: #dbeafe;
    }
    .btn-highlight {
      background: linear-gradient(135deg, #2563eb, #0284c7);
      color: #ffffff;
      font-size: 1.05rem;
      padding: 12px 28px;
    }
    .btn-highlight:hover {
      opacity: 0.95;
      color: #ffffff;
    }

    /* 首屏无图 Hero */
    .hero-section {
      background: radial-gradient(circle at 80% 20%, #eff6ff 0%, #ffffff 70%), #f8fafc;
      padding: 85px 0 65px;
      text-align: center;
      border-bottom: 1px solid var(--border-color);
    }
    .hero-content {
      max-width: 920px;
      margin: 0 auto;
    }
    .hero-h1 {
      font-size: 2.5rem;
      line-height: 1.25;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.03em;
    }
    .hero-p {
      font-size: 1.15rem;
      color: var(--text-muted);
      margin-bottom: 30px;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-btn-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }
    .hero-data-strip {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 30px;
      background: var(--bg-surface);
      padding: 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--card-shadow);
      border: 1px solid var(--border-color);
    }
    .data-item {
      text-align: center;
    }
    .data-num {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
    }
    .data-label {
      font-size: 0.85rem;
      color: var(--text-light);
      margin-top: 4px;
    }

    /* 平台介绍 */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      align-items: center;
    }
    .about-text-card {
      background: var(--bg-surface);
      padding: 36px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
    }
    .about-points {
      margin-top: 24px;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    .point-entry {
      display: flex;
      align-items: flex-start;
      gap: 12px;
    }
    .point-icon {
      background: #eff6ff;
      color: var(--primary);
      width: 24px;
      height: 24px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      font-size: 0.8rem;
      flex-shrink: 0;
      margin-top: 3px;
    }

    /* 模型矩阵徽章 */
    .model-tag-cloud {
      background: var(--bg-surface);
      padding: 30px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
    }
    .tag-container {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 16px;
    }
    .model-chip {
      background: var(--bg-subtle);
      color: var(--text-muted);
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: 6px;
      font-size: 0.85rem;
      font-weight: 500;
      transition: var(--transition);
    }
    .model-chip:hover {
      background: #eff6ff;
      color: var(--primary);
      border-color: #bfdbfe;
    }

    /* 卡片网格通用 */
    .feature-grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-2px);
    }
    .card-title {
      font-size: 1.15rem;
      font-weight: 600;
      margin-bottom: 10px;
      color: var(--text-main);
    }
    .card-desc {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 步骤流程 */
    .process-container {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .process-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px 20px;
      text-align: center;
      position: relative;
    }
    .process-idx {
      width: 36px;
      height: 36px;
      line-height: 36px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      font-weight: 700;
      margin: 0 auto 16px auto;
    }

    /* 案例中心图文 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--bg-surface);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .case-img-box {
      width: 100%;
      background: #f1f5f9;
      position: relative;
    }
    .case-img-box img {
      width: 100%;
      height: auto;
      display: block;
    }
    .case-body {
      padding: 24px;
    }

    /* 对比评测板块 */
    .review-highlight-box {
      background: linear-gradient(135deg, #1e3a8a, #1e40af);
      color: #ffffff;
      padding: 30px;
      border-radius: var(--radius-md);
      margin-bottom: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }
    .review-score-pane {
      display: flex;
      align-items: center;
      gap: 20px;
    }
    .score-badge {
      font-size: 3rem;
      font-weight: 900;
      line-height: 1;
      color: #fbbf24;
    }
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: var(--bg-surface);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
    }
    .comparison-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }
    .comparison-table th, .comparison-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }
    .comparison-table th {
      background: var(--bg-subtle);
      font-weight: 600;
      color: var(--text-main);
    }
    .comparison-table tr:last-child td {
      border-bottom: none;
    }
    .highlight-col {
      background: #eff6ff;
      color: var(--primary);
      font-weight: 600;
    }

    /* 用户评论 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }
    .testimonial-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--card-shadow);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .testimonial-user {
      margin-top: 16px;
      padding-top: 12px;
      border-top: 1px solid var(--border-color);
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.85rem;
    }
    .user-identity {
      font-weight: 600;
      color: var(--text-main);
    }
    .user-role {
      color: var(--text-light);
    }

    /* FAQ 折叠面板 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      overflow: hidden;
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      font-size: 1rem;
      font-weight: 600;
      background: none;
      border: none;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.2s;
    }
    .faq-answer {
      display: none;
      padding: 0 24px 18px;
      font-size: 0.92rem;
      color: var(--text-muted);
      border-top: 1px solid #f1f5f9;
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 表单与需求匹配 */
    .form-wrapper {
      background: var(--bg-surface);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      padding: 36px;
      max-width: 780px;
      margin: 0 auto;
    }
    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-bottom: 20px;
    }
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
      margin-bottom: 20px;
    }
    .form-label {
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--text-main);
    }
    .form-control {
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      background: var(--bg-page);
      color: var(--text-main);
      outline: none;
    }
    .form-control:focus {
      border-color: var(--primary);
      background: #ffffff;
    }

    /* 宣传图卡片 */
    .banner-preview-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 30px;
    }
    .banner-preview-card {
      border-radius: var(--radius-sm);
      overflow: hidden;
      border: 1px solid var(--border-color);
      background: #ffffff;
    }
    .ai-page-image {
      width: 100%;
      height: auto;
      display: block;
    }

    /* 联系我们 */
    .contact-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      align-items: center;
    }
    .contact-card-info {
      background: var(--bg-surface);
      padding: 32px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
    }
    .contact-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 20px;
    }
    .contact-item {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 0.95rem;
    }
    .qr-box {
      text-align: center;
      background: var(--bg-surface);
      padding: 24px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
    }
    .qr-box img {
      max-width: 180px;
      height: auto;
      margin-bottom: 12px;
      border-radius: var(--radius-sm);
    }

    /* 页脚 */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 50px 0 30px;
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 30px;
    }
    .footer-title {
      font-size: 1rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 14px;
    }
    .footer-links-group {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
    }
    .footer-links-group a {
      font-size: 0.9rem;
      color: var(--text-muted);
    }
    .footer-links-group a:hover {
      color: var(--primary);
    }
    .footer-bottom {
      padding-top: 24px;
      border-top: 1px solid var(--border-color);
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.85rem;
      color: var(--text-light);
    }

    /* 浮动客服 */
    .floating-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
      cursor: pointer;
      font-size: 0.85rem;
      font-weight: 600;
      border: none;
    }
    .float-btn:hover {
      background: var(--primary-hover);
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .feature-grid-4, .process-container, .banner-preview-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .feature-grid-3, .testimonial-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .about-grid, .contact-layout, .case-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .hero-h1 {
        font-size: 1.85rem;
      }
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        border-bottom: 1px solid var(--border-color);
        padding: 16px 20px;
        box-shadow: 0 10px 15px -3px rgba(0,0,0,0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-link-item {
        width: 100%;
        padding: 10px 0;
      }
      .nav-toggle-btn {
        display: block;
      }
      .hero-data-strip {
        grid-template-columns: repeat(2, 1fr);
      }
      .feature-grid-3, .feature-grid-4, .testimonial-grid, .banner-preview-grid, .process-container {
        grid-template-columns: 1fr;
      }
      .form-row {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .footer-bottom {
        flex-direction: column;
        gap: 10px;
        text-align: center;
      }
    }