:root {
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --bg-alt: #f1f5f9;
      --primary: #0284c7;
      --neon-cyan: #06b6d4;
      --neon-purple: #8b5cf6;
      --neon-pink: #ec4899;
      --neon-green: #10b981;
      --text-main: #0f172a;
      --text-muted: #334155;
      --text-sub: #64748b;
      --border-color: #e2e8f0;
      --card-shadow: 0 4px 20px -2px rgba(6, 182, 212, 0.08), 0 2px 6px -1px rgba(139, 92, 246, 0.05);
      --neon-shadow: 0 0 15px rgba(6, 182, 212, 0.35);
      --container-width: 1200px;
      --radius: 12px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "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;
      background-image: 
        radial-gradient(circle at 15% 10%, rgba(6, 182, 212, 0.07) 0%, transparent 45%),
        radial-gradient(circle at 85% 25%, rgba(139, 92, 246, 0.07) 0%, transparent 40%),
        radial-gradient(circle at 50% 80%, rgba(236, 72, 153, 0.05) 0%, transparent 50%);
      background-attachment: fixed;
    }

    a {
      color: inherit;
      text-decoration: none;
    }

    .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: 100;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(6, 182, 212, 0.2);
      box-shadow: 0 4px 12px rgba(15, 23, 42, 0.03);
    }

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

    .brand-logo {
      display: flex;
      align-items: center;
      gap: 12px;
      max-width: 180px;
    }

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

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

    .nav-links li a {
      display: inline-block;
      padding: 8px 14px;
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      transition: color 0.2s ease, text-shadow 0.2s ease;
      position: relative;
    }

    .nav-links li a:hover {
      color: var(--neon-purple);
      text-shadow: 0 0 8px rgba(139, 92, 246, 0.25);
    }

    .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;
      transition: all 0.25s ease;
      border: 1px solid transparent;
      text-align: center;
    }

    .btn-neon {
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(6, 182, 212, 0.35);
    }

    .btn-neon:hover {
      background: linear-gradient(135deg, #0891b2, #7c3aed);
      box-shadow: 0 6px 20px rgba(139, 92, 246, 0.45);
      transform: translateY(-2px);
      color: #ffffff;
    }

    .btn-outline {
      background: #ffffff;
      color: var(--primary);
      border: 1px solid rgba(6, 182, 212, 0.6);
    }

    .btn-outline:hover {
      background: rgba(6, 182, 212, 0.08);
      border-color: var(--neon-purple);
      color: var(--neon-purple);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
      padding: 6px;
    }

    /* 首屏 Hero 区域 (严格无图片) */
    .hero-section {
      padding: 75px 0 65px;
      position: relative;
      overflow: hidden;
      border-bottom: 1px solid rgba(139, 92, 246, 0.15);
    }

    .hero-wrapper {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      position: relative;
      z-index: 2;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      border-radius: 9999px;
      background: linear-gradient(90deg, rgba(6, 182, 212, 0.12), rgba(139, 92, 246, 0.12));
      border: 1px solid rgba(6, 182, 212, 0.35);
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      margin-bottom: 24px;
      box-shadow: 0 0 12px rgba(6, 182, 212, 0.15);
    }

    .hero-badge-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--neon-cyan);
      box-shadow: 0 0 8px var(--neon-cyan);
    }

    .hero-title {
      font-size: 40px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-title .glow-word {
      background: linear-gradient(135deg, #0284c7 0%, #8b5cf6 50%, #ec4899 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      text-shadow: 0 2px 10px rgba(139, 92, 246, 0.2);
    }

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

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 16px;
      margin-bottom: 48px;
    }

    .btn-hero-official {
      padding: 14px 34px;
      font-size: 16px;
      font-weight: 700;
      border-radius: 10px;
      background: linear-gradient(135deg, #06b6d4, #8b5cf6 60%, #ec4899);
      color: #ffffff;
      box-shadow: 0 6px 24px rgba(6, 182, 212, 0.45);
      border: 1px solid rgba(255, 255, 255, 0.6);
      transition: all 0.3s ease;
    }

    .btn-hero-official:hover {
      transform: translateY(-3px) scale(1.02);
      box-shadow: 0 10px 30px rgba(139, 92, 246, 0.55);
      color: #ffffff;
    }

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      width: 100%;
      max-width: 980px;
      margin-top: 10px;
    }

    .stat-card {
      background: #ffffff;
      border: 1px solid rgba(6, 182, 212, 0.25);
      border-radius: var(--radius);
      padding: 20px 16px;
      box-shadow: var(--card-shadow);
      position: relative;
      overflow: hidden;
      transition: transform 0.25s ease, border-color 0.25s ease;
    }

    .stat-card::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 3px;
      background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
    }

    .stat-card:hover {
      transform: translateY(-4px);
      border-color: var(--neon-purple);
    }

    .stat-number {
      font-size: 28px;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
    }

    .stat-label {
      font-size: 13px;
      color: var(--text-sub);
      font-weight: 500;
    }

    /* 区域公共样式 */
    .page-section {
      padding: 70px 0;
      position: relative;
    }

    .section-alt {
      background-color: rgba(241, 245, 249, 0.65);
      border-top: 1px solid rgba(226, 232, 240, 0.8);
      border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    }

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

    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      border-radius: 20px;
      background: rgba(6, 182, 212, 0.1);
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      margin-bottom: 12px;
      border: 1px solid rgba(6, 182, 212, 0.25);
    }

    .section-title {
      font-size: 30px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      line-height: 1.35;
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 平台介绍 */
    .intro-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .intro-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 28px 24px;
      box-shadow: var(--card-shadow);
      transition: all 0.25s ease;
      position: relative;
    }

    .intro-card:hover {
      transform: translateY(-4px);
      border-color: rgba(139, 92, 246, 0.4);
      box-shadow: 0 10px 25px -4px rgba(139, 92, 246, 0.15);
    }

    .intro-icon {
      width: 44px;
      height: 44px;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      background: linear-gradient(135deg, rgba(6, 182, 212, 0.15), rgba(139, 92, 246, 0.15));
      border: 1px solid rgba(6, 182, 212, 0.3);
      color: var(--primary);
      margin-bottom: 16px;
    }

    .intro-card h3 {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .intro-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 服务能力卡片列表 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .service-box {
      background: #ffffff;
      border: 1px solid rgba(6, 182, 212, 0.2);
      border-radius: var(--radius);
      padding: 22px 18px;
      box-shadow: var(--card-shadow);
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
    }

    .service-box:hover {
      border-color: var(--neon-cyan);
      box-shadow: 0 8px 22px rgba(6, 182, 212, 0.18);
      transform: translateY(-3px);
    }

    .service-badge {
      align-self: flex-start;
      font-size: 11px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 4px;
      margin-bottom: 12px;
      background: rgba(139, 92, 246, 0.12);
      color: var(--neon-purple);
      border: 1px solid rgba(139, 92, 246, 0.25);
    }

    .service-box h3 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .service-box p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 模型阵列标签云 */
    .model-tags-wrap {
      margin-top: 36px;
      padding: 24px;
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid rgba(139, 92, 246, 0.2);
      box-shadow: var(--card-shadow);
    }

    .model-tags-title {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      text-align: center;
    }

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

    .model-tag-item {
      display: inline-block;
      padding: 5px 12px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 600;
      color: var(--text-muted);
      background: var(--bg-alt);
      border: 1px solid var(--border-color);
      transition: all 0.2s ease;
    }

    .model-tag-item:hover {
      background: #ffffff;
      color: var(--neon-purple);
      border-color: var(--neon-purple);
      box-shadow: 0 0 10px rgba(139, 92, 246, 0.2);
    }

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

    .step-item {
      background: #ffffff;
      border-radius: var(--radius);
      padding: 24px 20px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      border-radius: 8px;
      background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
      color: #ffffff;
      font-weight: 800;
      font-size: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 14px;
      box-shadow: 0 4px 10px rgba(6, 182, 212, 0.3);
    }

    .step-item h3 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

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

    /* 案例中心 */
    .case-grid {
      display: grid;
      grid-template-columns: 1.2fr 1fr;
      gap: 24px;
      align-items: center;
      margin-bottom: 30px;
    }

    .case-image-box {
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid rgba(6, 182, 212, 0.3);
      box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
      background: #ffffff;
    }

    .case-image-box img {
      width: 100%;
      height: auto;
      display: block;
      transition: transform 0.3s ease;
    }

    .case-image-box:hover img {
      transform: scale(1.02);
    }

    .case-gallery-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

    .gallery-card {
      background: #ffffff;
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      transition: all 0.25s ease;
    }

    .gallery-card:hover {
      border-color: var(--neon-cyan);
      box-shadow: 0 6px 18px rgba(6, 182, 212, 0.15);
      transform: translateY(-3px);
    }

    .gallery-card .img-wrap {
      width: 100%;
      background: var(--bg-alt);
      overflow: hidden;
    }

    .gallery-card img {
      width: 100%;
      height: auto;
      display: block;
    }

    .gallery-card-body {
      padding: 16px;
    }

    .gallery-card-body h3 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .gallery-card-body p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 对比评测板块 */
    .eval-highlight {
      background: linear-gradient(135deg, rgba(6, 182, 212, 0.08), rgba(139, 92, 246, 0.08));
      border: 1px solid rgba(6, 182, 212, 0.35);
      border-radius: var(--radius);
      padding: 24px;
      text-align: center;
      margin-bottom: 30px;
      box-shadow: 0 4px 18px rgba(6, 182, 212, 0.08);
    }

    .eval-rating-line {
      font-size: 20px;
      font-weight: 800;
      color: var(--text-main);
      display: flex;
      justify-content: center;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }

    .stars-glow {
      color: #f59e0b;
      letter-spacing: 2px;
      text-shadow: 0 0 8px rgba(245, 158, 11, 0.4);
    }

    .score-badge {
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      padding: 4px 12px;
      border-radius: 6px;
      font-size: 16px;
      font-weight: 700;
      box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
    }

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

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

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

    .compare-table tr:hover td {
      background-color: rgba(6, 182, 212, 0.03);
    }

    .table-highlight-cell {
      background: rgba(6, 182, 212, 0.06);
      font-weight: 700;
      color: var(--primary);
    }

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

    .review-card {
      background: #ffffff;
      border-radius: var(--radius);
      padding: 22px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      transition: all 0.25s ease;
    }

    .review-card:hover {
      border-color: rgba(139, 92, 246, 0.4);
      transform: translateY(-3px);
      box-shadow: 0 8px 20px rgba(139, 92, 246, 0.1);
    }

    .review-content {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      margin-bottom: 16px;
      position: relative;
    }

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

    .user-avatar-tag {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
    }

    .user-meta-name {
      font-size: 14px;
      font-weight: 700;
      color: var(--text-main);
    }

    .user-meta-role {
      font-size: 12px;
      color: var(--text-sub);
    }

    /* 常见问题 FAQ */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
      box-shadow: 0 2px 6px rgba(15, 23, 42, 0.03);
      transition: border-color 0.2s ease;
    }

    .faq-item:hover {
      border-color: rgba(6, 182, 212, 0.5);
    }

    .faq-question {
      padding: 18px 20px;
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      user-select: none;
    }

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

    .faq-answer {
      display: none;
      padding: 0 20px 18px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      border-top: 1px dashed var(--border-color);
      margin-top: 4px;
      padding-top: 14px;
    }

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

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

    /* 最新资讯与文章 */
    .news-grid {
      display: grid;
      grid-template-columns: 1.2fr 1fr;
      gap: 24px;
    }

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

    .article-links-box h3 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      border-bottom: 2px solid rgba(6, 182, 212, 0.2);
      padding-bottom: 8px;
    }

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

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

    .article-links-list a {
      font-size: 13px;
      color: var(--primary);
      display: inline-block;
      word-break: break-all;
      transition: color 0.2s ease;
    }

    .article-links-list a:hover {
      color: var(--neon-purple);
      text-decoration: underline;
    }

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

    /* 表单与联系我们 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1.1fr 1fr;
      gap: 30px;
    }

    .form-box {
      background: #ffffff;
      padding: 30px;
      border-radius: var(--radius);
      border: 1px solid rgba(6, 182, 212, 0.3);
      box-shadow: var(--card-shadow);
    }

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

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

    .form-control {
      width: 100%;
      padding: 11px 14px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      font-size: 14px;
      color: var(--text-main);
      background: #ffffff;
      outline: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-control:focus {
      border-color: var(--neon-cyan);
      box-shadow: 0 0 8px rgba(6, 182, 212, 0.25);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 90px;
    }

    .contact-info-card {
      background: #ffffff;
      padding: 30px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .contact-details-list {
      list-style: none;
      margin-bottom: 20px;
    }

    .contact-details-list li {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .contact-qr-wrap {
      background: var(--bg-alt);
      padding: 16px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      text-align: center;
      display: inline-block;
      max-width: 170px;
      margin-top: 10px;
    }

    .contact-qr-wrap img {
      width: 130px;
      height: 130px;
      display: block;
      margin: 0 auto 8px;
      object-fit: cover;
      border-radius: 4px;
    }

    .contact-qr-wrap span {
      font-size: 12px;
      color: var(--text-sub);
      display: block;
    }

    /* 页脚 */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 40px 0 24px;
      color: var(--text-muted);
      font-size: 13px;
    }

    .footer-inner {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .footer-links-row {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 16px;
      padding-bottom: 16px;
      border-bottom: 1px solid var(--border-color);
    }

    .footer-links-row .links-label {
      font-weight: 700;
      color: var(--text-main);
    }

    .footer-links-row a {
      color: var(--text-muted);
      transition: color 0.2s ease;
    }

    .footer-links-row a:hover {
      color: var(--neon-purple);
    }

    .footer-bottom-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
      color: var(--text-sub);
    }

    /* 浮动组件 */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 80px;
      z-index: 99;
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 16px rgba(6, 182, 212, 0.4);
      cursor: pointer;
      font-size: 20px;
      transition: transform 0.2s ease;
    }

    .floating-kefu:hover {
      transform: scale(1.08);
    }

    .back-top-btn {
      position: fixed;
      right: 20px;
      bottom: 24px;
      z-index: 99;
      background: #ffffff;
      color: var(--text-main);
      border: 1px solid var(--border-color);
      width: 44px;
      height: 44px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
      cursor: pointer;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.25s ease, transform 0.25s ease;
    }

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

    .back-top-btn:hover {
      border-color: var(--neon-cyan);
      color: var(--neon-cyan);
      transform: translateY(-2px);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .intro-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .case-grid {
        grid-template-columns: 1fr;
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .hero-stats {
        grid-template-columns: repeat(2, 1fr);
      }
      .reviews-grid {
        grid-template-columns: 1fr;
      }
      .news-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        align-items: flex-start;
        padding: 16px 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links li a {
        padding: 10px 0;
        width: 100%;
      }
      .menu-toggle {
        display: block;
      }
      .hero-title {
        font-size: 28px;
      }
      .hero-desc {
        font-size: 15px;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .intro-grid {
        grid-template-columns: 1fr;
      }
      .steps-grid {
        grid-template-columns: 1fr;
      }
      .case-gallery-row {
        grid-template-columns: 1fr;
      }
      .hero-stats {
        grid-template-columns: 1fr;
      }
    }