:root {
      --primary: #0052d9;
      --primary-hover: #003cab;
      --accent: #ff6b00;
      --accent-light: #fff2e8;
      --bg-base: #f4f7fb;
      --bg-surface: #ffffff;
      --text-main: #18202c;
      --text-regular: #435266;
      --text-light: #708099;
      --border-color: #e5ebf3;
      --border-focus: #b2ccf8;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --shadow-sm: 0 4px 12px rgba(18, 38, 63, 0.04);
      --shadow-md: 0 10px 30px rgba(18, 38, 63, 0.08);
      --shadow-hover: 0 18px 40px rgba(0, 82, 217, 0.12);
      --transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
      --container-width: 1200px;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
      background-color: var(--bg-base);
      color: var(--text-main);
      line-height: 1.65;
      font-size: 15px;
      overflow-x: hidden;
    }

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

    ul, ol {
      list-style: none;
    }

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

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

    .section-wrap {
      padding: 70px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      margin-bottom: 44px;
    }

    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      background: #e8f1ff;
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      border-radius: 20px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 30px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.35;
      margin-bottom: 12px;
    }

    .section-desc {
      font-size: 15px;
      color: var(--text-regular);
      max-width: 680px;
      margin: 0 auto;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 999;
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

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

    .brand-logo-box .ai-page-logo {
      height: 40px;
      width: auto;
      max-height: 40px;
      object-fit: contain;
    }

    .brand-name {
      font-size: 20px;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }

    .nav-links li a {
      padding: 8px 12px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-regular);
      border-radius: var(--radius-sm);
      display: inline-block;
    }

    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--primary);
      background-color: #f0f5ff;
    }

    .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: var(--radius-sm);
      border: 1px solid transparent;
      cursor: pointer;
      transition: var(--transition);
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(0, 82, 217, 0.28);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(0, 82, 217, 0.38);
      transform: translateY(-1px);
    }

    .btn-accent {
      background-color: var(--accent);
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(255, 107, 0, 0.28);
    }

    .btn-accent:hover {
      background-color: #e55c00;
      transform: translateY(-1px);
    }

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

    .btn-outline:hover {
      background-color: #f0f5ff;
    }

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

    .mobile-menu-btn span {
      display: block;
      width: 22px;
      height: 2px;
      background: var(--text-main);
      margin: 4px 0;
      transition: var(--transition);
    }

    .hero-section {
      background: radial-gradient(circle at 85% 15%, #e8f0fe 0%, transparent 60%),
                  radial-gradient(circle at 10% 80%, #fff0e6 0%, transparent 50%),
                  #ffffff;
      padding: 85px 0 75px;
      border-bottom: 1px solid var(--border-color);
      position: relative;
    }

    .hero-content {
      max-width: 860px;
      margin: 0 auto;
      text-align: center;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: #eef4ff;
      border: 1px solid #d4e3fc;
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 13px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 38px;
      font-weight: 800;
      color: #101928;
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-subtitle {
      font-size: 17px;
      color: var(--text-regular);
      line-height: 1.6;
      margin-bottom: 34px;
      max-width: 740px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-actions {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 45px;
    }

    .btn-hero-portal {
      font-size: 16px;
      padding: 13px 32px;
      border-radius: var(--radius-md);
      background: linear-gradient(135deg, #ff6b00 0%, #ff8a33 100%);
      color: #ffffff;
      font-weight: 700;
      box-shadow: 0 8px 24px rgba(255, 107, 0, 0.3);
    }

    .btn-hero-portal:hover {
      box-shadow: 0 10px 28px rgba(255, 107, 0, 0.4);
      transform: translateY(-2px);
    }

    .hero-features-chips {
      display: flex;
      align-items: center;
      justify-content: center;
      flex-wrap: wrap;
      gap: 10px;
    }

    .hero-chip {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 12px;
      color: var(--text-regular);
      box-shadow: var(--shadow-sm);
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: -35px;
      position: relative;
      z-index: 2;
    }

    .stat-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px 20px;
      box-shadow: var(--shadow-md);
      text-align: center;
      transition: var(--transition);
    }

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

    .stat-num {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }

    .stat-title {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .stat-sub {
      font-size: 12px;
      color: var(--text-light);
    }

    .platform-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }

    .platform-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 30px;
    }

    .platform-item {
      padding: 22px;
      border-radius: var(--radius-md);
      background: #fafcff;
      border: 1px solid #ebf2fb;
      transition: var(--transition);
    }

    .platform-item:hover {
      background: #ffffff;
      border-color: var(--primary);
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
    }

    .platform-item h3 {
      font-size: 17px;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .platform-item p {
      font-size: 13px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    .model-tags-box {
      margin-top: 36px;
      padding: 24px;
      background: #f8fafc;
      border-radius: var(--radius-md);
      border: 1px dashed #d5e0ee;
    }

    .model-tags-title {
      font-size: 14px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
      text-align: center;
    }

    .model-tags-list {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 8px;
    }

    .model-tag {
      padding: 5px 12px;
      font-size: 12px;
      font-weight: 500;
      border-radius: 6px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      color: var(--text-regular);
    }

    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

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

    .service-badge {
      align-self: flex-start;
      font-size: 11px;
      padding: 3px 8px;
      background: var(--accent-light);
      color: var(--accent);
      border-radius: 4px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .service-card h3 {
      font-size: 18px;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .service-card p {
      font-size: 13px;
      color: var(--text-regular);
      line-height: 1.6;
      margin-bottom: 16px;
    }

    .service-meta {
      font-size: 12px;
      color: var(--primary);
      font-weight: 600;
      border-top: 1px dashed var(--border-color);
      padding-top: 12px;
    }

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

    .process-step {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
    }

    .step-badge {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      margin-bottom: 14px;
      font-size: 15px;
    }

    .process-step h3 {
      font-size: 16px;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .process-step p {
      font-size: 13px;
      color: var(--text-regular);
      line-height: 1.5;
    }

    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #eef2f8;
      overflow: hidden;
    }

    .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: 22px;
    }

    .case-tag {
      font-size: 12px;
      color: var(--primary);
      font-weight: 600;
      margin-bottom: 6px;
    }

    .case-body h3 {
      font-size: 17px;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .case-body p {
      font-size: 13px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    .banner-gallery {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 30px;
    }

    .banner-gallery-item {
      border-radius: var(--radius-sm);
      overflow: hidden;
      border: 1px solid var(--border-color);
      background: #eef2f7;
      box-shadow: var(--shadow-sm);
      aspect-ratio: 16 / 9;
    }

    .banner-gallery-item img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .review-score-hero {
      background: linear-gradient(135deg, #ffffff 0%, #f0f7ff 100%);
      border: 2px solid #b8d5ff;
      border-radius: var(--radius-lg);
      padding: 30px;
      text-align: center;
      margin-bottom: 30px;
      box-shadow: var(--shadow-sm);
    }

    .review-stars {
      font-size: 24px;
      color: #ff9800;
      margin-bottom: 8px;
    }

    .review-points {
      font-size: 42px;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
      margin-bottom: 6px;
    }

    .review-recommend {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      background: var(--bg-surface);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

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

    .compare-table th {
      background-color: #f7fafc;
      font-weight: 700;
      color: var(--text-main);
    }

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

    .col-highlight {
      background-color: #f4f8ff;
      font-weight: 600;
      color: var(--primary);
    }

    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

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

    .t-quote {
      font-size: 13px;
      color: var(--text-regular);
      line-height: 1.7;
      margin-bottom: 18px;
    }

    .t-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid var(--border-color);
      padding-top: 14px;
    }

    .t-avatar-initial {
      width: 40px;
      height: 40px;
      background: #e8f1ff;
      color: var(--primary);
      font-weight: 700;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 14px;
    }

    .t-info h4 {
      font-size: 14px;
      color: var(--text-main);
      line-height: 1.3;
    }

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

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

    .faq-item {
      background: var(--bg-surface);
      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;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #fafcff;
      border-top: 1px solid transparent;
    }

    .faq-answer-inner {
      padding: 16px 24px;
      font-size: 14px;
      color: var(--text-regular);
      line-height: 1.7;
    }

    .faq-item.active {
      border-color: var(--primary);
    }

    .faq-item.active .faq-answer {
      border-top-color: var(--border-color);
      max-height: 250px;
    }

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

    .article-links-box {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      margin-top: 24px;
    }

    .article-links-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 12px;
      margin-top: 12px;
    }

    .article-link-chip {
      padding: 10px 14px;
      background: #f7f9fc;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 13px;
      color: var(--primary);
      text-align: center;
      font-weight: 500;
    }

    .article-link-chip:hover {
      background: #ffffff;
      border-color: var(--primary);
    }

    .contact-form-layout {
      display: grid;
      grid-template-columns: 1.2fr 1fr;
      gap: 36px;
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }

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

    .form-group label {
      display: block;
      font-size: 13px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      font-size: 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      background: #fdfdfd;
      color: var(--text-main);
      outline: none;
      transition: var(--transition);
    }

    .form-control:focus {
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(0, 82, 217, 0.12);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 110px;
    }

    .contact-info-panel {
      background: #f7faff;
      border: 1px solid #dce8fc;
      border-radius: var(--radius-md);
      padding: 28px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .contact-info-list li {
      margin-bottom: 14px;
      font-size: 14px;
      color: var(--text-regular);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .contact-info-list strong {
      color: var(--text-main);
    }

    .qrcode-box {
      text-align: center;
      margin-top: 20px;
      padding-top: 20px;
      border-top: 1px dashed #ceddf5;
    }

    .qrcode-box img {
      width: 140px;
      height: 140px;
      object-fit: contain;
      margin: 0 auto 10px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-color);
      background: #fff;
      padding: 6px;
    }

    .qrcode-label {
      font-size: 12px;
      color: var(--text-light);
    }

    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 45px 0 25px;
      color: var(--text-regular);
    }

    .footer-top {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      gap: 30px;
      margin-bottom: 30px;
    }

    .footer-brand {
      max-width: 320px;
    }

    .footer-brand .brand-logo-box {
      margin-bottom: 12px;
    }

    .footer-brand p {
      font-size: 13px;
      color: var(--text-light);
      line-height: 1.6;
    }

    .footer-col h4 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
    }

    .footer-col ul li {
      margin-bottom: 8px;
    }

    .footer-col ul li a {
      font-size: 13px;
      color: var(--text-regular);
    }

    .footer-col ul li a:hover {
      color: var(--primary);
    }

    .friend-links-box {
      border-top: 1px solid var(--border-color);
      padding-top: 20px;
      margin-top: 20px;
    }

    .friend-links-box span {
      font-size: 13px;
      font-weight: 700;
      color: var(--text-main);
      margin-right: 12px;
    }

    .friend-links-list {
      display: inline-flex;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 13px;
    }

    .friend-links-list a {
      color: var(--text-regular);
    }

    .friend-links-list a:hover {
      color: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 20px;
      margin-top: 20px;
      text-align: center;
      font-size: 13px;
      color: var(--text-light);
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
    }

    .floating-tools {
      position: fixed;
      right: 20px;
      bottom: 30px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      z-index: 990;
    }

    .tool-btn {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      color: var(--text-main);
      box-shadow: var(--shadow-md);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      font-size: 13px;
      font-weight: 700;
      transition: var(--transition);
    }

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

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

    @media (max-width: 992px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        margin-top: 20px;
      }
      .services-grid,
      .platform-grid,
      .cases-grid,
      .testimonials-grid,
      .process-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .banner-gallery {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-form-layout {
        grid-template-columns: 1fr;
      }
      .nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
      .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        padding: 16px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.open li {
        width: 100%;
        text-align: center;
      }
      .nav-links.open li a {
        display: block;
        padding: 10px 0;
      }
    }

    @media (max-width: 640px) {
      .section-wrap {
        padding: 45px 0;
      }
      .hero-title {
        font-size: 26px;
      }
      .hero-subtitle {
        font-size: 14px;
      }
      .stats-grid {
        grid-template-columns: 1fr;
      }
      .services-grid,
      .platform-grid,
      .cases-grid,
      .testimonials-grid,
      .process-timeline,
      .banner-gallery {
        grid-template-columns: 1fr;
      }
      .footer-bottom {
        flex-direction: column;
        gap: 10px;
      }
      .brand-name {
        font-size: 18px;
      }
      .hero-actions {
        flex-direction: column;
        width: 100%;
      }
      .hero-actions .btn {
        width: 100%;
      }
    }