/* 全局 CSS 变量设定 - 鲜活高亮科技风 */
    :root {
      --primary-color: #2563eb;
      --primary-hover: #1d4ed8;
      --primary-light: #eff6ff;
      --accent-color: #0d9488;
      --accent-light: #ccfbf1;
      --text-main: #0f172a;
      --text-muted: #475569;
      --bg-page: #f8fafc;
      --bg-white: #ffffff;
      --border-color: #e2e8f0;
      --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.06);
      --card-hover-shadow: 0 12px 30px -4px rgba(37, 99, 235, 0.15);
      --container-max: 1200px;
      --transition: all 0.28s 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, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      overflow-x: hidden;
      width: 100%;
    }

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

    a:hover {
      color: var(--primary-hover);
    }

    /* 容器样式 */
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航 */
    .header-nav {
      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: 0 2px 10px rgba(0,0,0,0.03);
    }

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

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

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

    .brand-title {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

    /* Strict rule: .nav-links gap set to 0 as requested */
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }

    .nav-links li a {
      display: inline-block;
      padding: 8px 14px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: 6px;
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 14px;
      font-weight: 600;
      border-radius: 8px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary-color);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
    }

    .btn-outline {
      border-color: var(--primary-color);
      color: var(--primary-color);
      background-color: transparent;
    }

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

    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
    }

    /* 视觉区块统一规范 */
    .section-padding {
      padding: 80px 0;
    }

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

    .section-header {
      text-align: center;
      max-width: 800px;
      margin: 0 auto 50px auto;
    }

    .section-subtitle {
      display: inline-block;
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary-color);
      background: var(--primary-light);
      padding: 4px 14px;
      border-radius: 20px;
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 16px;
    }

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
    }

    /* 首屏 HERO 区域（严格遵守规则：无任何图片） */
    .hero-section {
      padding: 100px 0 80px 0;
      background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 50%, #f0fdf4 100%);
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #ffffff;
      border: 1px solid #dbeafe;
      padding: 6px 18px;
      border-radius: 30px;
      font-size: 14px;
      color: var(--primary-color);
      font-weight: 600;
      margin-bottom: 24px;
      box-shadow: 0 2px 10px rgba(37,99,235,0.08);
    }

    .hero-h1 {
      font-size: 42px;
      font-weight: 900;
      color: #0f172a;
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -1px;
    }

    .hero-lead {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 860px;
      margin: 0 auto 36px auto;
      line-height: 1.7;
    }

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

    .hero-btn-large {
      padding: 14px 36px;
      font-size: 16px;
      border-radius: 10px;
    }

    .hero-highlights {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
      margin-top: 40px;
      text-align: left;
    }

    .highlight-card {
      background: #ffffff;
      padding: 20px;
      border-radius: 12px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }

    .highlight-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--card-hover-shadow);
      border-color: #bfdbfe;
    }

    .highlight-icon {
      width: 44px;
      height: 44px;
      background: var(--primary-light);
      color: var(--primary-color);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
      margin-bottom: 14px;
    }

    .highlight-title {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 6px;
    }

    .highlight-desc {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 数据指标卡片 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: -40px;
      position: relative;
      z-index: 10;
    }

    .stat-card {
      background: #ffffff;
      padding: 28px 20px;
      border-radius: 16px;
      border: 1px solid var(--border-color);
      text-align: center;
      box-shadow: var(--card-shadow);
    }

    .stat-num {
      font-size: 36px;
      font-weight: 900;
      color: var(--primary-color);
      line-height: 1;
      margin-bottom: 8px;
    }

    .stat-label {
      font-size: 14px;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 服务能力卡片网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
      gap: 24px;
    }

    .service-card {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: 14px;
      padding: 28px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
      border-color: var(--primary-color);
    }

    .service-tag {
      font-size: 12px;
      font-weight: 700;
      color: var(--accent-color);
      background: var(--accent-light);
      padding: 3px 10px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 14px;
      width: fit-content;
    }

    .service-title {
      font-size: 19px;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .service-desc {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 20px;
      flex-grow: 1;
    }

    /* 对比评测表格 */
    .comparison-wrapper {
      background: #ffffff;
      border-radius: 16px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      overflow-x: auto;
      padding: 24px;
    }

    .evaluation-header-box {
      background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
      color: #ffffff;
      padding: 24px;
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 24px;
      flex-wrap: wrap;
      gap: 16px;
    }

    .score-badge {
      font-size: 32px;
      font-weight: 900;
      color: #facc15;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .stars {
      color: #facc15;
      font-size: 24px;
    }

    .comparison-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 650px;
    }

    .comparison-table th, 
    .comparison-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 14px;
    }

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

    .comparison-table td.highlight-col {
      background: #eff6ff;
      font-weight: 700;
      color: var(--primary-color);
    }

    /* 模型代币/Token比价卡片 */
    .models-cloud {
      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: 20px;
      font-size: 13px;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: 0 2px 6px rgba(0,0,0,0.02);
      transition: var(--transition);
    }

    .model-chip:hover {
      border-color: var(--primary-color);
      color: var(--primary-color);
      transform: translateY(-2px);
    }

    /* 步骤流程组件 */
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
      position: relative;
    }

    .step-card {
      background: #ffffff;
      padding: 24px;
      border-radius: 12px;
      border: 1px solid var(--border-color);
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary-color);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 16px;
      margin-bottom: 16px;
    }

    /* 用户评论组件 */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
      gap: 24px;
    }

    .review-card {
      background: #ffffff;
      padding: 24px;
      border-radius: 14px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-text {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 20px;
      line-height: 1.6;
    }

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

    .avatar-placeholder {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary-color);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
    }

    .author-info h4 {
      font-size: 15px;
      font-weight: 700;
    }

    .author-info p {
      font-size: 12px;
      color: var(--text-muted);
    }

    /* FAQ 折叠面板 */
    .faq-accordion {
      max-width: 900px;
      margin: 0 auto;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 10px;
      margin-bottom: 12px;
      overflow: hidden;
      transition: var(--transition);
    }

    .faq-item:hover {
      border-color: #bfdbfe;
    }

    .faq-header {
      padding: 18px 24px;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      user-select: none;
    }

    .faq-toggle-icon {
      font-size: 18px;
      color: var(--primary-color);
      transition: transform 0.3s ease;
    }

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

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

    .faq-item.active .faq-content {
      max-height: 300px;
      padding: 18px 24px;
      border-top: 1px solid var(--border-color);
    }

    /* 案例展示区 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
      gap: 24px;
    }

    .case-card {
      background: #ffffff;
      border-radius: 12px;
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }

    .case-img-wrap {
      width: 100%;
      background: #f1f5f9;
      overflow: hidden;
    }

    .case-img-wrap img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

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

    .case-body {
      padding: 20px;
    }

    .case-title {
      font-size: 17px;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .case-desc {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 表单组件 */
    .form-container {
      background: #ffffff;
      border-radius: 16px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      padding: 40px;
      max-width: 800px;
      margin: 0 auto;
    }

    .form-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .form-group.full-width {
      grid-column: span 2;
    }

    .form-group label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
    }

    .form-control {
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 14px;
      outline: none;
      transition: var(--transition);
      background: #f8fafc;
    }

    .form-control:focus {
      border-color: var(--primary-color);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 120px;
    }

    /* 统一页脚 */
    .footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 70px 0 30px 0;
      border-top: 1px solid #1e293b;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 50px;
    }

    .footer-brand h3 {
      color: #ffffff;
      font-size: 20px;
      margin-bottom: 14px;
    }

    .footer-brand p {
      font-size: 14px;
      line-height: 1.7;
      margin-bottom: 20px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 16px;
      margin-bottom: 18px;
    }

    .footer-links {
      list-style: none;
    }

    .footer-links li {
      margin-bottom: 10px;
    }

    .footer-links a {
      color: #94a3b8;
      font-size: 14px;
    }

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

    .footer-qr {
      text-align: center;
    }

    .footer-qr img {
      width: 120px;
      height: 120px;
      border-radius: 8px;
      background: #ffffff;
      padding: 6px;
      margin-bottom: 8px;
    }

    .footer-qr p {
      font-size: 12px;
      color: #cbd5e1;
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 13px;
    }

    .friend-links-box {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      align-items: center;
    }

    .friend-links-box a {
      color: #64748b;
    }

    .friend-links-box a:hover {
      color: #38bdf8;
    }

    /* 浮动客服入口 */
    .floating-contact {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary-color);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 14px rgba(0,0,0,0.2);
      cursor: pointer;
      transition: var(--transition);
      border: none;
      position: relative;
    }

    .float-btn:hover {
      transform: scale(1.08);
      background: var(--primary-hover);
    }

    .float-qr-popover {
      position: absolute;
      right: 60px;
      bottom: 0;
      background: #ffffff;
      padding: 12px;
      border-radius: 12px;
      box-shadow: 0 10px 25px rgba(0,0,0,0.15);
      display: none;
      width: 140px;
      text-align: center;
    }

    .float-btn:hover .float-qr-popover {
      display: block;
    }

    .float-qr-popover img {
      width: 100%;
      height: auto;
      border-radius: 6px;
    }

    .float-qr-popover p {
      font-size: 12px;
      color: var(--text-main);
      margin-top: 6px;
      font-weight: 600;
    }

    /* 响应式适配 */
    @media (max-width: 992px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        margin-top: 20px;
      }
      
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }

      .form-grid {
        grid-template-columns: 1fr;
      }

      .form-group.full-width {
        grid-column: span 1;
      }
    }

    @media (max-width: 768px) {
      .hero-h1 {
        font-size: 30px;
      }

      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }

      .nav-links.active {
        display: flex;
      }

      .mobile-menu-toggle {
        display: block;
      }

      .section-title {
        font-size: 26px;
      }

      .footer-grid {
        grid-template-columns: 1fr;
      }
    }