:root {
      --primary: #2563eb;
      --primary-hover: #1d4ed8;
      --primary-light: #eff6ff;
      --accent: #f97316;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --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 -1px rgba(0, 0, 0, 0.04);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --container-max: 1200px;
    }

    * {
      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;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color 0.2s ease;
    }

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

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

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

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

    .ai-page-logo {
      height: 42px;
      width: auto;
    }

    .brand-text {
      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 a {
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: var(--radius-sm);
      transition: all 0.2s ease;
    }

    .nav-links a:hover {
      color: var(--primary);
      background-color: var(--primary-light);
    }

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

    .btn-header-cta {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 18px;
      font-size: 0.95rem;
      font-weight: 600;
      color: #ffffff;
      background-color: var(--primary);
      border-radius: var(--radius-sm);
      transition: background-color 0.2s ease, transform 0.1s ease;
    }

    .btn-header-cta:hover {
      background-color: var(--primary-hover);
      color: #ffffff;
      transform: translateY(-1px);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
      padding: 6px;
    }

    /* 首屏 Hero (无图片) */
    .hero-section {
      background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 50%, #fff7ed 100%);
      padding: 90px 0 80px;
      border-bottom: 1px solid var(--border-color);
      text-align: center;
      position: relative;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      padding: 6px 14px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--primary);
      background: var(--primary-light);
      border: 1px solid #bfdbfe;
      border-radius: 9999px;
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.8px;
    }

    .hero-subtitle {
      font-size: 1.15rem;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px;
      line-height: 1.7;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 50px;
    }

    .btn-portal-primary {
      padding: 15px 34px;
      font-size: 1.1rem;
      font-weight: 700;
      color: #ffffff;
      background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
      border-radius: var(--radius-md);
      box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.35);
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-portal-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px 0 rgba(37, 99, 235, 0.45);
      color: #ffffff;
    }

    .btn-secondary {
      padding: 15px 30px;
      font-size: 1.1rem;
      font-weight: 600;
      color: var(--text-main);
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all 0.2s ease;
    }

    .btn-secondary:hover {
      background-color: #f1f5f9;
      border-color: #cbd5e1;
    }

    .hero-stats-grid {
      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: 20px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

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

    .stat-num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }

    .stat-label {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 区域通用规范 */
    .section-wrap {
      padding: 80px 0;
      border-bottom: 1px solid var(--border-color);
      background-color: #ffffff;
    }

    .section-wrap.alt-bg {
      background-color: #f8fafc;
    }

    .section-head {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 50px;
    }

    .section-badge {
      display: inline-block;
      font-size: 0.8rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary);
      margin-bottom: 8px;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }

    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 平台介绍板块 */
    .intro-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .intro-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 30px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

    .intro-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #cbd5e1;
    }

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

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

    /* 模型矩阵胶囊标签 */
    .model-pills {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 36px;
    }

    .model-pill {
      background: #f1f5f9;
      color: var(--text-main);
      font-size: 0.85rem;
      font-weight: 600;
      padding: 7px 16px;
      border-radius: 9999px;
      border: 1px solid var(--border-color);
      transition: all 0.2s ease;
    }

    .model-pill:hover {
      background: var(--primary-light);
      color: var(--primary);
      border-color: #bfdbfe;
    }

    /* 服务场景网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 26px;
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .service-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-md);
      transform: translateY(-3px);
    }

    .service-tag {
      align-self: flex-start;
      font-size: 0.75rem;
      font-weight: 700;
      color: var(--primary);
      background: var(--primary-light);
      padding: 3px 8px;
      border-radius: var(--radius-sm);
      margin-bottom: 14px;
    }

    .service-card h3 {
      font-size: 1.2rem;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .service-card p {
      font-size: 0.92rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 宣传与案例展示图 */
    .media-card-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
      margin-bottom: 30px;
      align-items: stretch;
    }

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

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

    .media-box:hover img {
      transform: scale(1.02);
    }

    .media-caption {
      padding: 16px 20px;
      background: #ffffff;
      border-top: 1px solid var(--border-color);
    }

    .media-caption h4 {
      font-size: 1.05rem;
      margin-bottom: 4px;
      color: var(--text-main);
    }

    .media-caption p {
      font-size: 0.85rem;
      color: var(--text-muted);
    }

    /* 流程步骤 */
    .flow-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .flow-step-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 24px;
      border-radius: var(--radius-md);
      position: relative;
    }

    .flow-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-bottom: 16px;
    }

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

    .flow-step-item p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 对比评测表格 */
    .compare-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }

    .compare-banner {
      background: #eff6ff;
      padding: 20px;
      border-bottom: 1px solid #bfdbfe;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }

    .rating-badge {
      font-size: 1.15rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .rating-badge span {
      color: var(--accent);
      font-size: 1.35rem;
    }

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
    }

    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

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

    .compare-table tr:last-child td {
      border-bottom: none;
    }

    .compare-table .highlight-col {
      background-color: #f0f7ff;
      font-weight: 600;
      color: var(--primary);
    }

    /* 客户评价板块 (6条评论) */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-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;
    }

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

    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }

    .user-avatar-placeholder {
      width: 44px;
      height: 44px;
      background: #e2e8f0;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--text-main);
    }

    .user-name {
      font-weight: 700;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .user-role {
      font-size: 0.8rem;
      color: var(--text-light);
    }

    /* 常见问题折叠面板 */
    .faq-accordion {
      max-width: 860px;
      margin: 0 auto;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      overflow: hidden;
      transition: border-color 0.2s ease;
    }

    .faq-question {
      padding: 18px 24px;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }

    .faq-question:hover {
      background-color: #f8fafc;
    }

    .faq-icon {
      font-size: 1.25rem;
      color: var(--text-light);
      transition: transform 0.25s ease;
    }

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

    .faq-answer {
      display: none;
      padding: 0 24px 20px;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* 需求匹配与联系我们表单 */
    .contact-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: start;
    }

    .contact-info-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .info-item {
      margin-bottom: 18px;
    }

    .info-label {
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--text-light);
      margin-bottom: 4px;
    }

    .info-val {
      font-size: 1.05rem;
      font-weight: 500;
      color: var(--text-main);
    }

    .qr-container {
      margin-top: 24px;
      display: inline-block;
      text-align: center;
      padding: 14px;
      background: #f8fafc;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
    }

    .qr-container img {
      width: 140px;
      height: 140px;
      margin: 0 auto 8px;
      display: block;
    }

    .qr-desc {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    .form-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

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

    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 6px;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      font-size: 0.95rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      background-color: #ffffff;
      color: var(--text-main);
      outline: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    .btn-submit {
      width: 100%;
      padding: 14px;
      background-color: var(--primary);
      color: #ffffff;
      border: none;
      border-radius: var(--radius-sm);
      font-size: 1rem;
      font-weight: 700;
      cursor: pointer;
      transition: background-color 0.2s ease;
    }

    .btn-submit:hover {
      background-color: var(--primary-hover);
    }

    /* 资讯与外链板块 */
    .article-list {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
      gap: 16px;
    }

    .article-item {
      display: block;
      padding: 14px 18px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.9rem;
      color: var(--text-main);
      font-weight: 500;
      transition: all 0.2s ease;
    }

    .article-item:hover {
      border-color: var(--primary);
      color: var(--primary);
      background-color: #f0f7ff;
    }

    /* 友情链接与底部 */
    .links-block {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 14px;
    }

    .links-block a {
      font-size: 0.85rem;
      color: var(--text-muted);
      background: #ffffff;
      padding: 6px 14px;
      border: 1px solid var(--border-color);
      border-radius: 4px;
      transition: all 0.2s ease;
    }

    .links-block a:hover {
      color: var(--primary);
      border-color: var(--primary);
    }

    .site-footer {
      background-color: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 40px 0 30px;
      color: var(--text-muted);
    }

    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
      font-size: 0.9rem;
    }

    .footer-left {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .ai-page-home-link {
      font-weight: 600;
      color: var(--primary);
    }

    /* 悬浮客服面板 */
    .float-panel {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: #ffffff;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      color: var(--text-main);
      font-size: 1.1rem;
      transition: all 0.2s ease;
    }

    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .intro-grid, .service-grid, .testimonials-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .flow-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .media-card-grid {
        grid-template-columns: 1fr;
      }
      .contact-layout {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        align-items: stretch;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
        padding: 10px 0;
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        padding: 12px 20px;
        border-radius: 0;
      }
      .menu-toggle {
        display: block;
      }
      .header-actions {
        display: none;
      }
      .hero-section {
        padding: 60px 0;
      }
      .hero-title {
        font-size: 1.8rem;
      }
      .hero-stats-grid {
        grid-template-columns: 1fr;
      }
      .intro-grid, .service-grid, .testimonials-grid, .flow-steps {
        grid-template-columns: 1fr;
      }
      .footer-content {
        flex-direction: column;
        text-align: center;
        justify-content: center;
      }
    }