:root {
      --primary-red: #d32f2f;
      --deep-red: #9a0007;
      --vibrant-red: #ff334b;
      --accent-gold: #e65100;
      --bg-light: #fffaf9;
      --card-bg: #ffffff;
      --text-main: #1f2429;
      --text-muted: #57606a;
      --border-subtle: #fbe9e7;
      --border-strong: #ffcdd2;
      --shadow-sm: 0 4px 12px rgba(211, 47, 47, 0.06);
      --shadow-md: 0 8px 24px rgba(211, 47, 47, 0.1);
      --shadow-hover: 0 16px 36px rgba(211, 47, 47, 0.18);
      --radius: 12px;
      --transition: all 0.28s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-tap-highlight-color: transparent;
    }

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

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

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

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

    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    .section-spacing {
      padding-top: 76px;
      padding-bottom: 76px;
    }

    .section-title-wrap {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-badge {
      display: inline-block;
      background: #ffebee;
      color: var(--deep-red);
      font-size: 0.875rem;
      font-weight: 700;
      padding: 6px 16px;
      border-radius: 999px;
      border: 1px solid var(--border-strong);
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 2.15rem;
      color: var(--text-main);
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.3;
    }

    .section-desc {
      margin-top: 12px;
      color: var(--text-muted);
      font-size: 1.05rem;
      max-width: 720px;
      margin-left: auto;
      margin-right: auto;
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-strong);
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
    }

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

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

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

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

    .nav-links li a {
      padding: 10px 14px;
      font-size: 0.95rem;
      color: var(--text-main);
      font-weight: 600;
      border-radius: 6px;
    }

    .nav-links li a:hover {
      color: var(--primary-red);
      background-color: #ffebee;
    }

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

    .btn-portal {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      background: linear-gradient(135deg, var(--primary-red), var(--deep-red));
      color: #ffffff;
      font-size: 0.95rem;
      font-weight: 700;
      border-radius: 8px;
      box-shadow: 0 4px 14px rgba(211, 47, 47, 0.35);
      border: 1px solid rgba(255, 255, 255, 0.2);
    }

    .btn-portal:hover {
      background: linear-gradient(135deg, #e53935, #b71c1c);
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(211, 47, 47, 0.45);
    }

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

    /* 首屏 Hero (无图片) */
    .hero-section {
      background: radial-gradient(circle at 85% 15%, #ffebee 0%, #fff 60%),
                  linear-gradient(180deg, #fff7f6 0%, #fff 100%);
      padding-top: 84px;
      padding-bottom: 90px;
      position: relative;
      border-bottom: 1px solid var(--border-subtle);
    }

    .hero-content {
      text-align: center;
      max-width: 960px;
      margin: 0 auto;
    }

    .hero-badge-wrap {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #ffcdd2;
      color: var(--deep-red);
      padding: 6px 18px;
      border-radius: 30px;
      font-weight: 700;
      font-size: 0.9rem;
      margin-bottom: 24px;
      border: 1px solid #ef9a9a;
    }

    .hero-heading {
      font-size: 2.85rem;
      line-height: 1.25;
      font-weight: 900;
      color: #1a1a1a;
      letter-spacing: -1px;
      margin-bottom: 24px;
    }

    .hero-heading span {
      color: var(--primary-red);
      position: relative;
      display: inline-block;
    }

    .hero-subtext {
      font-size: 1.2rem;
      color: var(--text-muted);
      line-height: 1.8;
      max-width: 820px;
      margin: 0 auto 36px;
    }

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

    .btn-primary-hero {
      background: linear-gradient(135deg, var(--vibrant-red), var(--deep-red));
      color: #ffffff;
      padding: 16px 36px;
      font-size: 1.125rem;
      font-weight: 800;
      border-radius: 10px;
      box-shadow: 0 10px 28px rgba(211, 47, 47, 0.4);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-primary-hero:hover {
      transform: translateY(-2px);
      box-shadow: 0 14px 34px rgba(211, 47, 47, 0.5);
    }

    .btn-secondary-hero {
      background: #ffffff;
      color: var(--deep-red);
      border: 2px solid var(--border-strong);
      padding: 15px 32px;
      font-size: 1.125rem;
      font-weight: 700;
      border-radius: 10px;
    }

    .btn-secondary-hero:hover {
      background: #ffebee;
      border-color: var(--primary-red);
    }

    /* 状态与指标面板 (纯代码构建) */
    .hero-metrics {
      margin-top: 56px;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .metric-box {
      background: #ffffff;
      padding: 24px 16px;
      border-radius: 14px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .metric-val {
      font-size: 2.25rem;
      font-weight: 800;
      color: var(--primary-red);
      margin-bottom: 6px;
    }

    .metric-label {
      font-size: 0.925rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* 模型矩阵胶囊条 */
    .model-ticker {
      background: #fff;
      padding: 28px 0;
      border-bottom: 1px solid var(--border-subtle);
    }

    .model-tag-list {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
    }

    .model-tag {
      background: #fff5f5;
      color: var(--deep-red);
      border: 1px solid #ffdcd9;
      font-size: 0.85rem;
      font-weight: 600;
      padding: 6px 14px;
      border-radius: 6px;
      transition: var(--transition);
    }

    .model-tag:hover {
      background: var(--primary-red);
      color: #fff;
      transform: translateY(-2px);
    }

    /* 关于与平台介绍 */
    .about-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 40px;
      align-items: center;
    }

    .about-card {
      background: #ffffff;
      padding: 40px;
      border-radius: 16px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
    }

    .feature-check-list {
      list-style: none;
      margin-top: 24px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

    .feature-check-item {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      font-size: 0.95rem;
      color: var(--text-main);
      font-weight: 600;
    }

    .feature-check-item svg {
      flex-shrink: 0;
      margin-top: 2px;
      color: var(--primary-red);
    }

    .about-highlight-box {
      background: linear-gradient(145deg, #ffebee, #ffffff);
      border: 2px solid var(--border-strong);
      border-radius: 16px;
      padding: 36px;
    }

    .about-highlight-box h3 {
      font-size: 1.5rem;
      color: var(--deep-red);
      margin-bottom: 16px;
    }

    /* 服务与能力网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: #ffffff;
      border: 1px solid var(--border-subtle);
      border-radius: 14px;
      padding: 32px 26px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--border-strong);
    }

    .service-icon-wrap {
      width: 52px;
      height: 52px;
      background: #ffebee;
      color: var(--primary-red);
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 12px;
      margin-bottom: 20px;
    }

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

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

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

    .step-node {
      background: #ffffff;
      border: 1px solid var(--border-subtle);
      border-radius: 14px;
      padding: 30px 22px;
      position: relative;
      box-shadow: var(--shadow-sm);
    }

    .step-badge {
      font-size: 0.85rem;
      font-weight: 800;
      color: var(--primary-red);
      background: #ffebee;
      padding: 4px 10px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 16px;
    }

    .step-title {
      font-size: 1.15rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

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

    /* 对比评测卡片与表格 */
    .review-summary-card {
      background: linear-gradient(135deg, #ffffff, #fff5f5);
      border: 2px solid var(--border-strong);
      border-radius: 16px;
      padding: 36px;
      margin-bottom: 36px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 24px;
    }

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

    .score-circle {
      width: 90px;
      height: 90px;
      background: var(--primary-red);
      color: #fff;
      border-radius: 50%;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      box-shadow: 0 8px 20px rgba(211, 47, 47, 0.3);
    }

    .score-num {
      font-size: 2rem;
      font-weight: 900;
      line-height: 1;
    }

    .score-max {
      font-size: 0.75rem;
      opacity: 0.85;
    }

    .score-detail h4 {
      font-size: 1.4rem;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .star-rating {
      color: #ff9800;
      font-size: 1.25rem;
      letter-spacing: 2px;
    }

    .table-responsive {
      overflow-x: auto;
      background: #ffffff;
      border-radius: 14px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-subtle);
    }

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }

    .compare-table th,
    .compare-table td {
      padding: 18px 24px;
      border-bottom: 1px solid #f0f0f0;
      font-size: 0.95rem;
    }

    .compare-table th {
      background: #ffebee;
      color: var(--deep-red);
      font-weight: 700;
    }

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

    .compare-table td.col-brand {
      background: #fffcfc;
      font-weight: 700;
      color: var(--primary-red);
    }

    /* 案例图片网格 (除首屏外展示) */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: #ffffff;
      border-radius: 14px;
      overflow: hidden;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .case-img-wrap {
      aspect-ratio: 16 / 10;
      overflow: hidden;
      background: #f5f5f5;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .case-card:hover .case-img-wrap img {
      transform: scale(1.04);
    }

    .case-body {
      padding: 24px;
    }

    .case-category {
      font-size: 0.8rem;
      color: var(--primary-red);
      font-weight: 700;
      text-transform: uppercase;
      margin-bottom: 8px;
    }

    .case-body h4 {
      font-size: 1.15rem;
      margin-bottom: 10px;
      color: var(--text-main);
    }

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

    /* 用户评论卡片 (6条) */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: #ffffff;
      border-radius: 14px;
      padding: 28px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .quote-content {
      font-size: 0.95rem;
      color: var(--text-main);
      line-height: 1.7;
      margin-bottom: 20px;
      position: relative;
    }

    .quote-author {
      display: flex;
      align-items: center;
      gap: 14px;
      border-top: 1px solid #f5f5f5;
      padding-top: 16px;
    }

    .author-avatar {
      width: 44px;
      height: 44px;
      background: #ffebee;
      color: var(--deep-red);
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      font-size: 1rem;
    }

    .author-meta h5 {
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .author-meta span {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    /* FAQ 手风琴 */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-subtle);
      border-radius: 10px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 20px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      user-select: none;
    }

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

    .faq-icon {
      font-size: 1.3rem;
      color: var(--primary-red);
      transition: transform 0.25s ease;
    }

    .faq-answer {
      display: none;
      padding: 0 24px 22px 24px;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.7;
    }

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

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

    /* 需求匹配与联系我们 (表单区) */
    .contact-layout {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 36px;
      align-items: flex-start;
    }

    .form-card {
      background: #ffffff;
      padding: 40px;
      border-radius: 16px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-md);
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-label {
      display: block;
      margin-bottom: 8px;
      font-size: 0.925rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 13px 16px;
      border: 1px solid #e0e0e0;
      border-radius: 8px;
      font-size: 0.95rem;
      color: var(--text-main);
      background-color: #fafafa;
      transition: var(--transition);
      font-family: inherit;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary-red);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.12);
    }

    .form-submit-btn {
      width: 100%;
      padding: 15px;
      background: linear-gradient(135deg, var(--primary-red), var(--deep-red));
      color: #ffffff;
      border: none;
      border-radius: 8px;
      font-size: 1.05rem;
      font-weight: 700;
      cursor: pointer;
      box-shadow: 0 8px 20px rgba(211, 47, 47, 0.35);
      transition: var(--transition);
    }

    .form-submit-btn:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 26px rgba(211, 47, 47, 0.45);
    }

    .contact-info-card {
      background: #ffffff;
      padding: 40px;
      border-radius: 16px;
      border: 1px solid var(--border-subtle);
      box-shadow: var(--shadow-sm);
    }

    .contact-detail-row {
      margin-bottom: 24px;
      display: flex;
      align-items: flex-start;
      gap: 16px;
    }

    .contact-icon-box {
      width: 44px;
      height: 44px;
      background: #ffebee;
      color: var(--primary-red);
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 10px;
      flex-shrink: 0;
    }

    .qrcode-wrapper {
      margin-top: 24px;
      padding-top: 24px;
      border-top: 1px solid #f0f0f0;
      text-align: center;
    }

    .qrcode-wrapper img {
      width: 130px;
      height: 130px;
      margin: 12px auto;
      border: 1px solid #eee;
      padding: 6px;
      background: #fff;
      border-radius: 8px;
    }

    /* 资讯与百科 */
    .article-pills-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
      justify-content: center;
      margin-top: 24px;
    }

    .article-pill {
      background: #ffffff;
      border: 1px solid var(--border-subtle);
      padding: 12px 20px;
      border-radius: 8px;
      font-size: 0.95rem;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .article-pill:hover {
      border-color: var(--primary-red);
      color: var(--primary-red);
      transform: translateY(-2px);
    }

    /* 页脚 */
    .site-footer {
      background: #191c20;
      color: #c4c9d0;
      padding-top: 64px;
      padding-bottom: 40px;
      border-top: 3px solid var(--primary-red);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
      gap: 40px;
      margin-bottom: 48px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1.15rem;
      margin-bottom: 20px;
      font-weight: 700;
    }

    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .footer-links a {
      color: #9ea5b0;
      font-size: 0.925rem;
    }

    .footer-links a:hover {
      color: #ff8a80;
      padding-left: 4px;
    }

    .friend-links-area {
      border-top: 1px solid #2e333a;
      padding-top: 24px;
      margin-bottom: 24px;
      font-size: 0.875rem;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 16px;
    }

    .friend-links-area span {
      color: #88909c;
      font-weight: 700;
    }

    .friend-links-area a {
      color: #a0a6b1;
    }

    .friend-links-area a:hover {
      color: #ffffff;
      text-decoration: underline;
    }

    .copyright-bar {
      border-top: 1px solid #282c32;
      padding-top: 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 14px;
      font-size: 0.85rem;
      color: #7b8390;
    }

    /* 浮动组件与返回顶部 */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 80px;
      z-index: 999;
      background: linear-gradient(135deg, var(--primary-red), var(--deep-red));
      color: #fff;
      padding: 12px 18px;
      border-radius: 30px;
      box-shadow: 0 8px 24px rgba(211, 47, 47, 0.4);
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.9rem;
      font-weight: 700;
      cursor: pointer;
    }

    .back-to-top {
      position: fixed;
      right: 20px;
      bottom: 24px;
      z-index: 999;
      width: 44px;
      height: 44px;
      background: #ffffff;
      border: 1px solid #ddd;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary-red);
      cursor: pointer;
      box-shadow: var(--shadow-sm);
      opacity: 0;
      pointer-events: none;
      transition: var(--transition);
    }

    .back-to-top.visible {
      opacity: 1;
      pointer-events: auto;
    }

    /* 响应式适配 */
    @media (max-width: 1024px) {
      .hero-heading {
        font-size: 2.3rem;
      }
      .service-grid,
      .cases-grid,
      .testimonials-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-wrapper {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .section-spacing {
        padding-top: 56px;
        padding-bottom: 56px;
      }
      .hero-heading {
        font-size: 1.85rem;
      }
      .hero-subtext {
        font-size: 1.05rem;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-strong);
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .about-grid,
      .contact-layout {
        grid-template-columns: 1fr;
      }
      .service-grid,
      .cases-grid,
      .testimonials-grid,
      .steps-wrapper,
      .footer-grid,
      .hero-metrics {
        grid-template-columns: 1fr;
      }
      .feature-check-list {
        grid-template-columns: 1fr;
      }
      .form-card,
      .contact-info-card,
      .about-card {
        padding: 24px;
      }
    }