:root {
      --primary: #0052d9;
      --primary-hover: #003cab;
      --primary-light: #e8f3ff;
      --accent: #00b42a;
      --text-main: #1d2129;
      --text-regular: #4e5969;
      --text-muted: #86909c;
      --bg-page: #f7f9fc;
      --bg-card: #ffffff;
      --border-color: #e5e6eb;
      --container-width: 1200px;
      --shadow-sm: 0 2px 8px rgba(0, 82, 217, 0.06);
      --shadow-md: 0 8px 24px rgba(0, 82, 217, 0.08);
      --shadow-lg: 0 16px 36px rgba(0, 82, 217, 0.12);
      --radius: 8px;
      --transition: all 0.25s ease-in-out;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", 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;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    .container {
      width: 100%;
      max-width: var(--container-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .brand-box .ai-page-logo {
      height: 38px;
      width: auto;
    }
    .brand-name {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }
    .nav-item {
      padding: 8px 12px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-regular);
      border-radius: 4px;
    }
    .nav-item:hover, .nav-item.active {
      color: var(--primary);
      background: var(--primary-light);
    }
    .header-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 20px;
      font-size: 14px;
      font-weight: 600;
      border-radius: var(--radius);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(0, 82, 217, 0.25);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 16px rgba(0, 82, 217, 0.35);
    }
    .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
      background: #ffffff;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }
    .mobile-menu-btn span {
      display: block;
      width: 22px;
      height: 2px;
      background: var(--text-main);
      margin: 4px 0;
      transition: var(--transition);
    }

    /* 首屏 Hero (无任何图片) */
    .hero-section {
      padding: 80px 0 60px;
      background: linear-gradient(180deg, #edf5ff 0%, #f7f9fc 100%);
      border-bottom: 1px solid var(--border-color);
      text-align: center;
    }
    .hero-badge {
      display: inline-block;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid #c9dffc;
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      border-radius: 30px;
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
    }
    .hero-title {
      font-size: 38px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-title span {
      color: var(--primary);
    }
    .hero-subtitle {
      max-width: 760px;
      margin: 0 auto 36px;
      font-size: 16px;
      color: var(--text-regular);
      line-height: 1.8;
    }
    .hero-cta {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 50px;
    }
    .hero-cta .btn {
      padding: 12px 28px;
      font-size: 15px;
    }
    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1000px;
      margin: 0 auto;
    }
    .stat-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 24px 16px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .stat-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #b0d4ff;
    }
    .stat-value {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 6px;
    }
    .stat-label {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 模块通用样式 */
    .section-block {
      padding: 70px 0;
      border-bottom: 1px solid var(--border-color);
    }
    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      color: var(--primary);
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: 8px;
    }
    .section-heading {
      font-size: 28px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }
    .section-desc {
      font-size: 15px;
      color: var(--text-regular);
      max-width: 680px;
      margin: 0 auto;
    }

    /* 网格布局 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

    /* 卡片体系 */
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #bad9ff;
    }
    .feature-icon {
      width: 44px;
      height: 44px;
      border-radius: 8px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
      margin-bottom: 18px;
    }
    .feature-title {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 10px;
      color: var(--text-main);
    }
    .feature-desc {
      font-size: 14px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    /* 平台介绍与图文 */
    .media-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .media-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #f0f2f5;
      overflow: hidden;
    }
    .media-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }
    .media-card:hover .media-img-wrap img {
      transform: scale(1.03);
    }
    .media-content {
      padding: 20px;
    }
    .media-title {
      font-size: 16px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .media-desc {
      font-size: 13px;
      color: var(--text-regular);
    }

    /* 标签云与模型矩阵 */
    .tag-cluster {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 24px;
    }
    .tag-item {
      padding: 6px 14px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      font-size: 13px;
      color: var(--text-regular);
      border-radius: 20px;
      transition: var(--transition);
    }
    .tag-item:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: var(--primary-light);
    }

    /* 标准流程时间线 */
    .flow-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px 20px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }
    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 16px;
      font-size: 15px;
    }
    .step-title {
      font-size: 16px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .step-text {
      font-size: 13px;
      color: var(--text-regular);
    }

    /* 对比表格 */
    .compare-wrap {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      overflow-x: auto;
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 600px;
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 14px;
    }
    .compare-table th {
      background: #fafbfe;
      color: var(--text-main);
      font-weight: 600;
    }
    .compare-table tr:last-child td {
      border-bottom: none;
    }
    .highlight-col {
      background: #f4f8ff;
      color: var(--primary);
      font-weight: 600;
    }
    .rating-badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #fff7e6;
      border: 1px solid #ffd591;
      padding: 4px 8px;
      border-radius: 4px;
      font-weight: 700;
      color: #d46b08;
      font-size: 13px;
    }

    /* 常见问题折叠面板 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      border: 1px solid var(--border-color);
      background: #ffffff;
      border-radius: var(--radius);
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-question {
      padding: 18px 20px;
      font-size: 15px;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      user-select: none;
    }
    .faq-question::after {
      content: "+";
      font-size: 18px;
      color: var(--primary);
      transition: transform 0.2s;
    }
    .faq-item.active .faq-question::after {
      content: "-";
    }
    .faq-answer {
      display: none;
      padding: 0 20px 18px;
      font-size: 14px;
      color: var(--text-regular);
      line-height: 1.7;
      border-top: 1px dashed var(--border-color);
      margin-top: 4px;
      padding-top: 12px;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* 客户评论 */
    .review-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }
    .review-header {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
    }
    .review-avatar {
      width: 44px;
      height: 44px;
      background: var(--primary-light);
      color: var(--primary);
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
    }
    .review-info h4 {
      font-size: 15px;
      font-weight: 600;
    }
    .review-info p {
      font-size: 12px;
      color: var(--text-muted);
    }
    .review-text {
      font-size: 13.5px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    /* 表单与需求匹配 */
    .form-wrapper {
      max-width: 680px;
      margin: 0 auto;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 36px 30px;
      box-shadow: var(--shadow-sm);
    }
    .form-group {
      margin-bottom: 18px;
    }
    .form-label {
      display: block;
      font-size: 14px;
      font-weight: 600;
      margin-bottom: 6px;
      color: var(--text-main);
    }
    .form-control {
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border-color);
      border-radius: 6px;
      font-size: 14px;
      color: var(--text-main);
      outline: none;
      transition: var(--transition);
      background: #fcfdfe;
    }
    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(0, 82, 217, 0.1);
      background: #ffffff;
    }
    textarea.form-control {
      min-height: 100px;
      resize: vertical;
    }

    /* 文章列表 */
    .article-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
      max-width: 800px;
      margin: 0 auto;
    }
    .article-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      transition: var(--transition);
    }
    .article-item:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-sm);
      transform: translateX(4px);
    }
    .article-link {
      font-size: 15px;
      color: var(--text-main);
      font-weight: 500;
    }
    .article-tag {
      font-size: 12px;
      color: var(--primary);
      background: var(--primary-light);
      padding: 2px 8px;
      border-radius: 4px;
    }

    /* 友情链接区 */
    .links-box {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      justify-content: center;
      padding: 16px 0;
    }
    .links-box a {
      font-size: 13px;
      color: var(--text-regular);
      padding: 4px 10px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 4px;
    }
    .links-box a:hover {
      color: var(--primary);
      border-color: var(--primary);
    }

    /* 页脚 */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 40px 0 20px;
      color: var(--text-regular);
    }
    .footer-top {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 30px;
    }
    .footer-col h4 {
      font-size: 15px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 14px;
    }
    .footer-col p {
      font-size: 13px;
      line-height: 1.8;
      margin-bottom: 8px;
    }
    .footer-qr {
      width: 100px;
      height: 100px;
      border: 1px solid var(--border-color);
      padding: 4px;
      border-radius: 6px;
      background: #ffffff;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 20px;
      text-align: center;
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 悬浮客服 */
    .floating-service {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      align-items: center;
      background: #ffffff;
      padding: 8px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-lg);
      cursor: pointer;
      transition: var(--transition);
    }
    .floating-service:hover {
      transform: translateY(-4px);
    }
    .floating-service img {
      width: 80px;
      height: 80px;
      border-radius: 4px;
    }
    .floating-label {
      font-size: 11px;
      font-weight: 600;
      color: var(--primary);
      margin-top: 4px;
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .flow-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-stats {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-top {
        grid-template-columns: 1fr;
        gap: 20px;
      }
    }

    @media (max-width: 768px) {
      .mobile-menu-btn {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        border-bottom: 1px solid var(--border-color);
        padding: 16px 20px;
        box-shadow: var(--shadow-md);
      }
      .nav-links.show {
        display: flex;
      }
      .nav-item {
        width: 100%;
        padding: 10px 0;
      }
      .grid-3, .grid-2, .grid-4 {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 26px;
      }
      .hero-subtitle {
        font-size: 14px;
      }
      .hero-cta {
        flex-direction: column;
        align-items: stretch;
      }
      .hero-stats {
        grid-template-columns: 1fr;
      }
      .flow-steps {
        grid-template-columns: 1fr;
      }
    }