/* CSS 全局变量与鲜活明亮风格 */
    :root {
      --primary: #2563eb;
      --primary-hover: #1d4ed8;
      --primary-light: #eff6ff;
      --accent: #0ea5e9;
      --accent-glow: #38bdf8;
      --orange: #f97316;
      --green: #10b981;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --bg-soft: #f1f5f9;
      --text-main: #0f172a;
      --text-sub: #334155;
      --text-muted: #64748b;
      --border-color: #e2e8f0;
      --border-focus: #93c5fd;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 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, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --radius-full: 9999px;
      --container-width: 1200px;
      --transition: all 0.25s ease-in-out;
    }

    *, *::before, *::after {
      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, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    /* 统一居中容器 */
    .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: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
    }
    .brand-logo .ai-page-logo {
      height: 38px;
      width: auto;
      display: block;
    }
    .nav-links {
      display: flex;
      align-items: center;
      list-style: none;
      gap: 0;
    }
    .nav-links li a, .nav-links .ai-page-home-link {
      display: inline-block;
      padding: 8px 14px;
      color: var(--text-sub);
      font-weight: 500;
      font-size: 15px;
      text-decoration: none;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }
    .nav-links li a:hover, .nav-links .ai-page-home-link:hover {
      color: var(--primary);
      background-color: var(--primary-light);
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    /* 按钮规范 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-full);
      text-decoration: none;
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: #ffffff;
      box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.35);
    }
    .btn-primary:hover {
      background: linear-gradient(135deg, var(--primary-hover), var(--primary));
      box-shadow: 0 6px 20px 0 rgba(37, 99, 235, 0.45);
      transform: translateY(-1px);
    }
    .btn-outline {
      background-color: #ffffff;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background-color: var(--primary-light);
      transform: translateY(-1px);
    }
    .btn-orange {
      background: linear-gradient(135deg, #ff8a00, var(--orange));
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(249, 115, 22, 0.35);
    }
    .btn-orange:hover {
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(249, 115, 22, 0.45);
    }
    .btn-lg {
      padding: 14px 32px;
      font-size: 16px;
    }

    /* 移动端菜单切换 */
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
      padding: 6px;
    }

    /* 通用章节规范 */
    .section {
      padding: 80px 0;
      position: relative;
    }
    .section-alt {
      background-color: #ffffff;
    }
    .section-header {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 50px auto;
    }
    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      background-color: var(--primary-light);
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      border-radius: var(--radius-full);
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-subtitle {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 首屏 Hero（严禁出现任何图片） */
    .hero-section {
      padding: 90px 0 70px 0;
      background: radial-gradient(circle at 50% 10%, #dbeafe 0%, #f8fafc 70%);
      text-align: center;
      position: relative;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid var(--border-focus);
      border-radius: var(--radius-full);
      font-size: 14px;
      color: var(--primary);
      font-weight: 600;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }
    .hero-title {
      font-size: 46px;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-title span {
      background: linear-gradient(135deg, #1d4ed8, #0284c7);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-desc {
      font-size: 18px;
      color: var(--text-sub);
      max-width: 820px;
      margin: 0 auto 36px auto;
      line-height: 1.8;
    }
    .hero-ctas {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 50px;
    }
    .hero-data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 20px;
    }
    .hero-data-card {
      background: #ffffff;
      padding: 24px 20px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
      transition: var(--transition);
    }
    .hero-data-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: var(--border-focus);
    }
    .data-num {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }
    .data-label {
      font-size: 14px;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 平台支持的大模型标签墙 */
    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }
    .model-pill {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: var(--radius-full);
      font-size: 13px;
      font-weight: 600;
      color: var(--text-sub);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .model-pill:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: var(--primary-light);
      transform: scale(1.05);
    }

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

    /* 场景卡片样式 */
    .feature-card {
      background: #ffffff;
      padding: 28px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-lg);
      border-color: var(--border-focus);
    }
    .feature-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 18px;
      margin-bottom: 18px;
    }
    .feature-title {
      font-size: 19px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }
    .feature-desc {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.65;
      margin-bottom: 16px;
      flex-grow: 1;
    }
    .feature-tag {
      font-size: 12px;
      color: var(--accent);
      background: #f0f9ff;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
      align-self: flex-start;
      font-weight: 600;
    }

    /* 流程步骤 */
    .process-timeline {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .process-step {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .step-number {
      font-size: 28px;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .step-title {
      font-size: 17px;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .step-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 案例展示带图结构 */
    .case-card {
      background: #ffffff;
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
    }
    .case-media {
      width: 100%;
      background: #e2e8f0;
      overflow: hidden;
    }
    .case-media img {
      width: 100%;
      height: auto;
      display: block;
      transition: var(--transition);
    }
    .case-card:hover .case-media img {
      transform: scale(1.03);
    }
    .case-body {
      padding: 22px;
    }
    .case-title {
      font-size: 18px;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .case-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 对比评测表格 */
    .rating-banner {
      background: linear-gradient(135deg, #1e3a8a, #2563eb);
      color: #ffffff;
      padding: 30px;
      border-radius: var(--radius-lg);
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 30px;
      flex-wrap: wrap;
      gap: 20px;
    }
    .rating-info h3 {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 6px;
    }
    .rating-info p {
      color: #bfdbfe;
      font-size: 15px;
    }
    .rating-score {
      display: flex;
      align-items: center;
      gap: 15px;
    }
    .score-big {
      font-size: 48px;
      font-weight: 900;
      color: #fde047;
      line-height: 1;
    }
    .score-detail {
      font-size: 14px;
      line-height: 1.4;
    }
    .stars {
      color: #fde047;
      font-size: 18px;
      letter-spacing: 2px;
    }
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 14px;
    }
    .compare-table th {
      background: #f8fafc;
      font-weight: 700;
      color: var(--text-main);
    }
    .compare-table th.highlight, .compare-table td.highlight {
      background: #eff6ff;
      color: var(--primary);
      font-weight: 700;
    }
    .check-yes {
      color: var(--green);
      font-weight: bold;
    }
    .check-no {
      color: #ef4444;
      font-weight: bold;
    }

    /* 用户评论网格 */
    .review-card {
      background: #ffffff;
      padding: 26px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      transition: var(--transition);
    }
    .review-card:hover {
      box-shadow: var(--shadow-lg);
      border-color: var(--border-focus);
    }
    .review-quote {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.7;
      margin-bottom: 20px;
      font-style: italic;
    }
    .review-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }
    .author-avatar {
      width: 42px;
      height: 42px;
      border-radius: var(--radius-full);
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 15px;
    }
    .author-meta h4 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
    }
    .author-meta p {
      font-size: 12px;
      color: var(--text-muted);
    }

    /* FAQ 手风琴 */
    .faq-wrapper {
      max-width: 900px;
      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;
      transition: var(--transition);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      font-size: 16px;
      font-weight: 600;
      color: var(--text-main);
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: var(--transition);
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-icon {
      font-size: 18px;
      font-weight: 400;
      transition: transform 0.3s ease;
    }
    .faq-answer {
      padding: 0 24px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      color: var(--text-sub);
      font-size: 14px;
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      padding: 0 24px 20px 24px;
      max-height: 250px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 需求匹配与表单 */
    .form-box {
      background: #ffffff;
      padding: 36px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-lg);
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      display: block;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 8px;
    }
    .form-control {
      width: 100%;
      padding: 12px 16px;
      font-size: 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      background-color: #f8fafc;
      color: var(--text-main);
      transition: var(--transition);
    }
    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }
    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    /* 联系我们与客服渠道 */
    .contact-card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      margin-bottom: 40px;
    }
    .contact-item {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      text-align: center;
      box-shadow: var(--shadow-sm);
    }
    .contact-item h4 {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .contact-item p {
      font-size: 14px;
      color: var(--text-sub);
    }
    .kefu-qr-box {
      text-align: center;
      padding: 20px;
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      display: inline-block;
    }
    .kefu-qr-box img {
      max-width: 160px;
      height: auto;
      border-radius: var(--radius-sm);
      display: block;
      margin: 0 auto 10px auto;
    }

    /* 文章列表 */
    .article-link-list {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }
    .article-chip {
      padding: 8px 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-full);
      color: var(--text-sub);
      text-decoration: none;
      font-size: 13px;
      transition: var(--transition);
    }
    .article-chip:hover {
      background: var(--primary-light);
      border-color: var(--primary);
      color: var(--primary);
    }

    /* 友情链接区 */
    .friendly-links-section {
      padding: 30px 0;
      background: #f1f5f9;
      border-top: 1px solid var(--border-color);
    }
    .friendly-links-wrap {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 16px;
      font-size: 13px;
    }
    .friendly-links-wrap a {
      color: var(--text-muted);
      text-decoration: none;
      transition: var(--transition);
    }
    .friendly-links-wrap a:hover {
      color: var(--primary);
    }

    /* 页脚 */
    .site-footer {
      background-color: #0f172a;
      color: #94a3b8;
      padding: 50px 0 30px 0;
      font-size: 14px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-col h4 {
      color: #f8fafc;
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .footer-col p {
      line-height: 1.8;
      margin-bottom: 12px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .footer-links a {
      color: #94a3b8;
      text-decoration: none;
      transition: var(--transition);
    }
    .footer-links a:hover {
      color: #38bdf8;
    }
    .footer-bottom {
      border-top: 1px solid #334155;
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: #64748b;
    }

    /* 浮动客服入口 */
    .float-kefu {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 999;
      background: var(--primary);
      color: #ffffff;
      width: 52px;
      height: 52px;
      border-radius: var(--radius-full);
      box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
      display: flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
      font-weight: bold;
      font-size: 13px;
      transition: var(--transition);
    }
    .float-kefu:hover {
      transform: scale(1.1);
      background: var(--primary-hover);
    }

    /* 响应式媒体查询 */
    @media (max-width: 992px) {
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .process-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-data-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
      }
      .hero-title {
        font-size: 36px;
      }
      .contact-card-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .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: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .hero-title {
        font-size: 28px;
      }
      .grid-3, .grid-2, .grid-4, .process-timeline, .hero-data-grid {
        grid-template-columns: 1fr;
      }
      .section {
        padding: 50px 0;
      }
      .rating-banner {
        flex-direction: column;
        text-align: center;
      }
      .rating-score {
        justify-content: center;
      }
    }