:root {
      --primary: #2563eb;
      --primary-dark: #1d4ed8;
      --accent: #f97316;
      --accent-hover: #ea580c;
      --bg-base: #f8fafc;
      --bg-surface: #ffffff;
      --bg-alt: #eff6ff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --border-color: #e2e8f0;
      --border-focus: #3b82f6;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
      --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --radius-full: 9999px;
      --container-max: 1200px;
      --transition: all 0.25s ease-in-out;
    }

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

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-base);
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
      color: var(--text-main);
      overflow-x: hidden;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

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

    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }

    /* 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);
    }

    .nav-wrapper {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }

    .brand-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .brand-area img.ai-page-logo {
      height: 40px;
      width: auto;
      display: block;
    }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }

    .nav-links li a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
    }

    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--primary);
      background-color: var(--bg-alt);
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }

    .mobile-menu-btn span {
      display: block;
      width: 24px;
      height: 2px;
      background-color: var(--text-main);
      margin: 5px 0;
      transition: var(--transition);
    }

    /* 按钮规范 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius-md);
      transition: var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
      color: #ffffff;
    }

    .btn-accent {
      background-color: var(--accent);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(249, 115, 22, 0.25);
    }

    .btn-accent:hover {
      background-color: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(249, 115, 22, 0.35);
      color: #ffffff;
    }

    .btn-outline {
      border-color: var(--border-color);
      background-color: #ffffff;
      color: var(--text-main);
    }

    .btn-outline:hover {
      border-color: var(--primary);
      color: var(--primary);
      background-color: var(--bg-alt);
    }

    /* 首屏 Hero */
    .hero-section {
      padding: 70px 0 60px;
      background: linear-gradient(135deg, #ffffff 0%, #eff6ff 50%, #fef3c7 100%);
      border-bottom: 1px solid var(--border-color);
      position: relative;
    }

    .hero-container {
      text-align: center;
      max-width: 900px;
      margin: 0 auto;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 6px 16px;
      background: rgba(37, 99, 235, 0.1);
      color: var(--primary);
      border-radius: var(--radius-full);
      font-size: 0.875rem;
      font-weight: 600;
      margin-bottom: 20px;
      border: 1px solid rgba(37, 99, 235, 0.2);
    }

    .hero-title {
      font-size: 2.75rem;
      line-height: 1.25;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
    }

    .hero-cta {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 30px;
    }

    .metric-card {
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(8px);
      border: 1px solid var(--border-color);
      padding: 20px 16px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
    }

    .metric-val {
      font-size: 1.85rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }

    .metric-lbl {
      font-size: 0.85rem;
      color: var(--text-muted);
      margin-top: 4px;
    }

    /* 模块通用样式 */
    .section {
      padding: 70px 0;
      border-bottom: 1px solid var(--border-color);
    }

    .section-header {
      text-align: center;
      max-width: 700px;
      margin: 0 auto 50px;
    }

    .section-subtitle {
      font-size: 0.875rem;
      font-weight: 700;
      text-transform: uppercase;
      color: var(--accent);
      letter-spacing: 1px;
      margin-bottom: 8px;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 12px;
    }

    .section-desc {
      font-size: 1rem;
      color: var(--text-muted);
    }

    /* 服务能力卡片网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background-color: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: rgba(37, 99, 235, 0.3);
    }

    .service-badge {
      display: inline-block;
      align-self: flex-start;
      padding: 4px 10px;
      background: var(--bg-alt);
      color: var(--primary);
      font-size: 0.75rem;
      font-weight: 700;
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
    }

    .service-card h3 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .service-card p {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 模型矩阵标签墙 */
    .models-wall {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: var(--radius-full);
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--text-main);
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }

    .model-chip:hover {
      border-color: var(--accent);
      color: var(--accent);
      transform: scale(1.05);
    }

    /* 流程步骤 */
    .workflow-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-md);
      padding: 24px 20px;
      position: relative;
      box-shadow: var(--shadow-sm);
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      font-weight: 700;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
      font-size: 1.1rem;
    }

    .step-item h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .step-item p {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* 案例展示 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .case-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-3px);
    }

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #e2e8f0;
      overflow: hidden;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

    .case-card:hover .case-img-wrap img {
      transform: scale(1.03);
    }

    .case-content {
      padding: 20px;
    }

    .case-content h4 {
      font-size: 1.15rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .case-content p {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* 对比评测表格与卡片 */
    .review-score-box {
      background: linear-gradient(135deg, #eff6ff 0%, #fef3c7 100%);
      border: 2px solid #bfdbfe;
      border-radius: var(--radius-lg);
      padding: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 24px;
      margin-bottom: 30px;
    }

    .score-left h3 {
      font-size: 1.5rem;
      font-weight: 800;
      margin-bottom: 6px;
    }

    .score-left p {
      color: var(--text-muted);
      font-size: 0.95rem;
    }

    .score-right {
      display: flex;
      align-items: center;
      gap: 20px;
    }

    .score-stars {
      color: #eab308;
      font-size: 1.5rem;
      letter-spacing: 2px;
    }

    .score-big {
      font-size: 2.5rem;
      font-weight: 900;
      color: var(--primary);
    }

    .score-big span {
      font-size: 1.1rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.95rem;
      min-width: 600px;
    }

    .compare-table th,
    .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }

    .compare-table th {
      background-color: #f8fafc;
      font-weight: 700;
      color: var(--text-main);
    }

    .compare-table tbody tr:hover {
      background-color: var(--bg-alt);
    }

    .compare-table .highlight {
      font-weight: 700;
      color: var(--primary);
    }

    /* 用户评论 */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .review-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-text {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 20px;
    }

    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .review-avatar {
      width: 44px;
      height: 44px;
      background: var(--bg-alt);
      border: 1px solid rgba(37, 99, 235, 0.2);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
    }

    .review-info h5 {
      font-size: 0.95rem;
      font-weight: 700;
    }

    .review-info span {
      font-size: 0.8rem;
      color: var(--text-light);
    }

    /* FAQ 折叠面板 */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      background: none;
      border: none;
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: var(--transition);
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-icon {
      font-size: 1.25rem;
      transition: transform 0.25s ease;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background: #f8fafc;
      padding: 0 24px;
    }

    .faq-answer p {
      padding: 16px 0;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      border-top: 1px dashed var(--border-color);
    }

    /* 表单与联系区 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      gap: 40px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }

    .contact-info h3 {
      font-size: 1.5rem;
      font-weight: 800;
      margin-bottom: 16px;
    }

    .contact-info p {
      color: var(--text-muted);
      font-size: 0.95rem;
      margin-bottom: 24px;
    }

    .contact-details {
      display: flex;
      flex-direction: column;
      gap: 14px;
      margin-bottom: 30px;
    }

    .contact-row {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .qr-container {
      display: inline-block;
      padding: 8px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      max-width: 140px;
    }

    .qr-container img {
      width: 100%;
      height: auto;
      display: block;
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      transition: var(--transition);
      background-color: #f8fafc;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--border-focus);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }

    textarea.form-control {
      min-height: 110px;
      resize: vertical;
    }

    /* 资讯与友情链接 */
    .articles-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 30px;
      margin-bottom: 40px;
    }

    .article-links {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
      margin-top: 16px;
    }

    .article-link-item {
      padding: 8px 16px;
      background: var(--bg-alt);
      border-radius: var(--radius-sm);
      font-size: 0.9rem;
      color: var(--primary);
      font-weight: 500;
    }

    .article-link-item:hover {
      background: rgba(37, 99, 235, 0.15);
    }

    .footer-links-box {
      border-top: 1px solid var(--border-color);
      padding-top: 30px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 16px;
    }

    .footer-links-box span {
      font-weight: 700;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .footer-links-box a {
      color: var(--text-muted);
      font-size: 0.9rem;
    }

    .footer-links-box a:hover {
      color: var(--primary);
    }

    /* 页脚 */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 40px 0 30px;
      margin-top: auto;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 30px;
    }

    .footer-brand h4 {
      color: #ffffff;
      font-size: 1.25rem;
      margin-bottom: 12px;
    }

    .footer-brand p {
      font-size: 0.9rem;
      line-height: 1.6;
    }

    .footer-col h5 {
      color: #ffffff;
      font-size: 1rem;
      margin-bottom: 14px;
    }

    .footer-col ul {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .footer-col ul a {
      color: #94a3b8;
      font-size: 0.9rem;
    }

    .footer-col ul a:hover {
      color: #ffffff;
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 20px;
      text-align: center;
      font-size: 0.85rem;
    }

    /* 悬浮客服 */
    .floating-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .floating-btn {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-lg);
      cursor: pointer;
      transition: var(--transition);
      border: none;
      font-size: 1.2rem;
    }

    .floating-btn:hover {
      background: var(--accent);
      transform: scale(1.1);
    }

    /* 响应式媒体查询 */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .services-grid,
      .case-grid,
      .reviews-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .workflow-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @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;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links li a {
        display: block;
        padding: 10px 0;
      }
      .hero-title {
        font-size: 1.85rem;
      }
      .services-grid,
      .case-grid,
      .reviews-grid,
      .workflow-steps {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .score-right {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
      }
    }