:root {
      --primary-red: #d91b24;
      --primary-red-hover: #b8141c;
      --primary-red-light: #fff1f0;
      --primary-red-subtle: #ffd8d6;
      --accent-gold: #f59e0b;
      --text-main: #1d2129;
      --text-muted: #4e5969;
      --text-light: #86909c;
      --bg-page: #fbfbfc;
      --bg-card: #ffffff;
      --border-color: #f2dcdc;
      --container-width: 1200px;
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 18px;
      --shadow-sm: 0 2px 8px rgba(217, 27, 36, 0.04);
      --shadow-md: 0 8px 24px rgba(217, 27, 36, 0.08);
      --shadow-lg: 0 16px 36px rgba(217, 27, 36, 0.12);
      --transition: all 0.25s ease;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.65;
      -webkit-font-smoothing: antialiased;
    }

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

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

    /* 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-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }

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

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

    .nav-item a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 10px 14px;
      display: inline-block;
      border-radius: var(--radius-sm);
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 15px;
      font-weight: 600;
      padding: 10px 22px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
    }

    .btn-primary {
      background: var(--primary-red);
      color: #ffffff !important;
      box-shadow: 0 4px 12px rgba(217, 27, 36, 0.25);
    }

    .btn-primary:hover {
      background: var(--primary-red-hover);
      transform: translateY(-2px);
    }

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

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

    .btn-accent {
      background: #e6222b;
      color: #fff;
      font-size: 16px;
      padding: 14px 32px;
      border-radius: 30px;
      box-shadow: 0 8px 20px rgba(217, 27, 36, 0.3);
    }

    .btn-accent:hover {
      background: #c0151d;
      transform: translateY(-2px);
    }

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

    /* 首屏 Hero - 无图片 pure CSS 风格 */
    .hero-section {
      background: radial-gradient(circle at 50% -20%, #ffebec 0%, #fff7f7 50%, var(--bg-page) 100%);
      padding: 70px 0 60px;
      text-align: center;
      border-bottom: 1px solid var(--border-color);
      position: relative;
    }

    .hero-tagline {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: var(--primary-red-light);
      border: 1px solid var(--primary-red-subtle);
      color: var(--primary-red);
      font-size: 14px;
      font-weight: 600;
      padding: 6px 16px;
      border-radius: 20px;
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.25;
      color: #b8141c;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px;
      line-height: 1.7;
    }

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

    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px 30px;
      box-shadow: var(--shadow-md);
      text-align: left;
    }

    .metric-item {
      border-right: 1px solid var(--border-color);
      padding-right: 15px;
    }

    .metric-item:last-child {
      border-right: none;
      padding-right: 0;
    }

    .metric-num {
      font-size: 30px;
      font-weight: 800;
      color: var(--primary-red);
      line-height: 1.2;
    }

    .metric-label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-top: 4px;
    }

    .metric-desc {
      font-size: 12px;
      color: var(--text-light);
      margin-top: 2px;
    }

    /* 通用区块排版 */
    .section-wrap {
      padding: 70px 0;
      border-bottom: 1px solid #f2ecec;
    }

    .section-head {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 48px;
    }

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

    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 12px;
    }

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

    /* 多模型聚合卡片 */
    .model-tags-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 30px;
      box-shadow: var(--shadow-sm);
    }

    .model-chips {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 20px;
    }

    .chip {
      background: #fff8f8;
      border: 1px solid #fedbdc;
      color: var(--text-main);
      font-size: 13px;
      font-weight: 500;
      padding: 6px 14px;
      border-radius: 20px;
      transition: var(--transition);
    }

    .chip:hover {
      border-color: var(--primary-red);
      color: var(--primary-red);
      background: #ffebeb;
    }

    .chip.highlight {
      background: var(--primary-red-light);
      color: var(--primary-red);
      font-weight: 700;
      border-color: var(--primary-red);
    }

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

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

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

    .service-icon-wrap {
      width: 46px;
      height: 46px;
      border-radius: var(--radius-sm);
      background: var(--primary-red-light);
      color: var(--primary-red);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 18px;
    }

    .service-card h3 {
      font-size: 19px;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .service-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 16px;
    }

    .service-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      margin-top: auto;
    }

    .service-tag {
      font-size: 12px;
      background: #f7f8fa;
      color: var(--text-muted);
      padding: 3px 8px;
      border-radius: 4px;
    }

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

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

    .step-num {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      background: var(--primary-red);
      color: #fff;
      font-weight: 700;
      font-size: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 14px;
    }

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

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

    /* 对比评测模块 */
    .evaluation-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }

    .eval-header {
      background: linear-gradient(135deg, #d91b24 0%, #b8141c 100%);
      color: #ffffff;
      padding: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }

    .eval-score-box {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .eval-star {
      color: #ffda44;
      font-size: 22px;
      letter-spacing: 2px;
    }

    .eval-score {
      font-size: 40px;
      font-weight: 900;
      line-height: 1;
    }

    .eval-score span {
      font-size: 18px;
      font-weight: 400;
      opacity: 0.85;
    }

    .eval-table-wrap {
      overflow-x: auto;
    }

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

    .eval-table th, .eval-table td {
      padding: 16px 20px;
      border-bottom: 1px solid #f0f0f0;
      font-size: 14px;
    }

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

    .eval-table tr:hover {
      background: #fffafa;
    }

    .badge-win {
      color: var(--primary-red);
      font-weight: 700;
      background: var(--primary-red-light);
      padding: 2px 8px;
      border-radius: 4px;
    }

    /* 案例中心图文卡片 */
    .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-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 10;
      background: #eee;
      overflow: hidden;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .case-body {
      padding: 20px;
    }

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

    .case-desc {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 用户评论卡片 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

    .testi-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }

    .testi-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
    }

    .user-avatar-initial {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-red-light);
      color: var(--primary-red);
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 16px;
    }

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

    .user-info span {
      font-size: 12px;
      color: var(--text-light);
    }

    .testi-content {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 表单与需求匹配 */
    .contact-form-container {
      display: grid;
      grid-template-columns: 1.2fr 1fr;
      gap: 36px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }

    .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: 12px 14px;
      border: 1px solid #dcdfe6;
      border-radius: var(--radius-sm);
      font-size: 14px;
      transition: var(--transition);
      background: #fafafa;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary-red);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(217, 27, 36, 0.1);
    }

    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

    /* FAQ 手风琴 */
    .faq-accordion {
      max-width: 900px;
      margin: 0 auto;
    }

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

    .faq-question {
      padding: 18px 24px;
      font-size: 16px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #ffffff;
      transition: var(--transition);
    }

    .faq-question:hover {
      background: #fff8f8;
      color: var(--primary-red);
    }

    .faq-icon {
      font-size: 18px;
      transition: transform 0.25s ease;
      color: var(--primary-red);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      padding: 0 24px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      background: #fafafa;
    }

    .faq-item.active .faq-answer {
      max-height: 250px;
      padding: 16px 24px;
      border-top: 1px solid #f2e4e4;
    }

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

    /* 资讯与百科 */
    .info-dual-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }

    .info-list-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
    }

    .info-list-box h3 {
      font-size: 19px;
      font-weight: 700;
      margin-bottom: 18px;
      border-left: 4px solid var(--primary-red);
      padding-left: 10px;
    }

    .news-link-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 12px 0;
      border-bottom: 1px dashed #eee;
      font-size: 14px;
    }

    .news-link-item:hover a {
      color: var(--primary-red);
    }

    .news-link-item:last-child {
      border-bottom: none;
    }

    /* 友情链接与页脚 */
    .site-footer {
      background: #191c22;
      color: #b0b4be;
      padding: 60px 0 30px;
      font-size: 14px;
    }

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

    .footer-title {
      font-size: 16px;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 18px;
    }

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

    .footer-links-list a {
      color: #b0b4be;
    }

    .footer-links-list a:hover {
      color: #ff6b72;
    }

    .friend-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
    }

    .friend-links-wrap a {
      color: #a0a5b1;
      background: #252932;
      padding: 4px 10px;
      border-radius: 4px;
      font-size: 13px;
    }

    .friend-links-wrap a:hover {
      color: #ffffff;
      background: var(--primary-red);
    }

    .footer-bottom {
      border-top: 1px solid #282d38;
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      color: #7d8392;
      font-size: 13px;
    }

    /* 浮动客服 */
    .floating-contact {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary-red);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 18px;
      box-shadow: 0 4px 14px rgba(217, 27, 36, 0.4);
      cursor: pointer;
      border: none;
      transition: var(--transition);
      position: relative;
    }

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

    .qr-popover {
      display: none;
      position: absolute;
      right: 58px;
      bottom: 0;
      background: #fff;
      padding: 12px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      width: 160px;
      text-align: center;
      color: var(--text-main);
    }

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

    .qr-popover img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-sm);
      margin-bottom: 6px;
    }

    .qr-popover span {
      font-size: 12px;
      font-weight: 600;
      color: var(--primary-red);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .services-grid, .case-grid, .testimonials-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .metric-item:nth-child(2) {
        border-right: none;
      }
      .process-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-form-container {
        grid-template-columns: 1fr;
      }
      .footer-top {
        grid-template-columns: 1fr 1fr;
      }
      .nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
      .nav-links.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        border-bottom: 1px solid var(--border-color);
        padding: 16px;
        box-shadow: var(--shadow-md);
      }
    }

    @media (max-width: 600px) {
      .hero-title {
        font-size: 28px;
      }
      .services-grid, .case-grid, .testimonials-grid, .info-dual-grid, .process-timeline {
        grid-template-columns: 1fr;
      }
      .hero-metrics {
        grid-template-columns: 1fr;
      }
      .metric-item {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding-bottom: 12px;
      }
      .metric-item:last-child {
        border-bottom: none;
      }
      .form-row {
        grid-template-columns: 1fr;
      }
      .footer-top {
        grid-template-columns: 1fr;
      }
    }