:root {
      --primary: #2563eb;
      --primary-hover: #1d4ed8;
      --primary-light: #eff6ff;
      --accent: #06b6d4;
      --accent-gradient: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
      --text-main: #1e293b;
      --text-muted: #64748b;
      --bg-base: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --border-hover: #cbd5e1;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-main);
      background-color: var(--bg-base);
      line-height: 1.6;
    }

    body {
      overflow-x: hidden;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    .brand-area {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
    }

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

    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

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

    .nav-links li a, .nav-links a {
      display: inline-block;
      padding: 8px 14px;
      font-size: 0.9375rem;
      font-weight: 500;
      color: var(--text-muted);
      text-decoration: none;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 0.9375rem;
      font-weight: 600;
      padding: 10px 20px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
    }

    .btn-primary {
      background: var(--accent-gradient);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
    }

    .btn-primary:hover {
      box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
      transform: translateY(-1px);
    }

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

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

    .btn-lg {
      padding: 14px 28px;
      font-size: 1.0625rem;
      border-radius: var(--radius-md);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      padding: 8px;
      cursor: pointer;
      color: var(--text-main);
    }

    /* 首屏 Hero */
    .hero-section {
      position: relative;
      padding: 80px 0 60px;
      background: radial-gradient(100% 100% at 50% 0%, #eff6ff 0%, #f8fafc 100%);
      border-bottom: 1px solid var(--border-color);
      text-align: center;
      overflow: hidden;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid #bfdbfe;
      border-radius: 9999px;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
    }

    .hero-title {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.25;
      color: #0f172a;
      margin-bottom: 20px;
      letter-spacing: -0.02em;
    }

    .hero-subtitle {
      max-width: 780px;
      margin: 0 auto 36px;
      font-size: 1.125rem;
      color: var(--text-muted);
      line-height: 1.7;
    }

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

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 960px;
      margin: 0 auto;
      text-align: left;
    }

    .stat-card {
      background: #ffffff;
      padding: 20px 24px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .stat-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
      border-color: #bfdbfe;
    }

    .stat-value {
      font-size: 1.75rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
    }

    .stat-label {
      font-size: 0.875rem;
      color: var(--text-muted);
    }

    /* 通用Section */
    .section {
      padding: 80px 0;
      border-bottom: 1px solid var(--border-color);
    }

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

    .section-header {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 50px;
    }

    .section-tag {
      font-size: 0.875rem;
      font-weight: 700;
      color: var(--primary);
      text-transform: uppercase;
      letter-spacing: 0.05em;
      margin-bottom: 8px;
      display: block;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: #0f172a;
      margin-bottom: 16px;
      letter-spacing: -0.01em;
    }

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

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

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

    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
      align-items: center;
    }

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

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: #bfdbfe;
    }

    .feature-icon {
      width: 48px;
      height: 48px;
      border-radius: var(--radius-sm);
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      font-size: 1.25rem;
      margin-bottom: 20px;
    }

    .feature-card h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 12px;
      color: #0f172a;
    }

    .feature-card p {
      font-size: 0.9375rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 标签云 */
    .model-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-tag {
      padding: 8px 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 9999px;
      font-size: 0.875rem;
      font-weight: 500;
      color: #334155;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .model-tag:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: var(--primary-light);
    }

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

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

    .step-number {
      font-size: 2rem;
      font-weight: 800;
      color: #cbd5e1;
      margin-bottom: 8px;
      line-height: 1;
    }

    .step-item h4 {
      font-size: 1.125rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: #0f172a;
    }

    .step-item p {
      font-size: 0.875rem;
      color: var(--text-muted);
    }

    /* 表格容器 */
    .table-container {
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }

    table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.9375rem;
    }

    th, td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }

    th {
      background: #f8fafc;
      font-weight: 600;
      color: #334155;
    }

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

    .badge-star {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 4px 10px;
      background: #fef3c7;
      color: #b45309;
      border-radius: 9999px;
      font-weight: 600;
      font-size: 0.8125rem;
    }

    /* 图片响应式包装 */
    .img-wrapper {
      width: 100%;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      background: #ffffff;
      box-shadow: var(--shadow-sm);
    }

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

    /* FAQ 手风琴 */
    .faq-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
    }

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

    .faq-question {
      padding: 18px 20px;
      font-weight: 600;
      font-size: 1rem;
      color: #0f172a;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }

    .faq-question:hover {
      background: #f8fafc;
    }

    .faq-question::after {
      content: "+";
      font-size: 1.25rem;
      font-weight: 400;
      color: var(--text-muted);
      transition: transform 0.2s;
    }

    .faq-item.active .faq-question::after {
      content: "-";
      transform: rotate(180deg);
    }

    .faq-answer {
      display: none;
      padding: 0 20px 18px;
      font-size: 0.9375rem;
      color: var(--text-muted);
      line-height: 1.6;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }

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

    /* 评论卡片 */
    .review-card {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    .review-avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }

    .review-meta h4 {
      font-size: 0.9375rem;
      font-weight: 600;
      color: #0f172a;
    }

    .review-meta span {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    .review-content {
      font-size: 0.9375rem;
      color: #475569;
      line-height: 1.6;
    }

    /* 表单与联系 */
    .form-wrapper {
      background: #ffffff;
      padding: 36px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }

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

    .form-label {
      display: block;
      font-size: 0.875rem;
      font-weight: 600;
      color: #334155;
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.9375rem;
      outline: none;
      transition: var(--transition);
      background: #f8fafc;
    }

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

    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    .contact-info-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 24px;
    }

    .contact-item {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 0.9375rem;
      color: #334155;
    }

    .qr-container {
      margin-top: 20px;
      padding: 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      display: inline-block;
      text-align: center;
    }

    .qr-container img {
      width: 130px;
      height: 130px;
      display: block;
      margin: 0 auto 8px;
    }

    /* 文章列表 */
    .article-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 14px 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      text-decoration: none;
      color: var(--text-main);
      transition: var(--transition);
    }

    .article-item:hover {
      border-color: var(--primary);
      transform: translateX(4px);
    }

    .article-title {
      font-weight: 500;
      font-size: 0.9375rem;
    }

    .article-time {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    /* 友情链接 */
    .links-bar {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      align-items: center;
    }

    .links-bar a {
      font-size: 0.875rem;
      color: var(--text-muted);
      text-decoration: none;
      padding: 4px 10px;
      background: #f1f5f9;
      border-radius: 4px;
      transition: var(--transition);
    }

    .links-bar a:hover {
      color: var(--primary);
      background: var(--primary-light);
    }

    /* 页脚 */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 50px 0 30px;
      color: var(--text-muted);
      font-size: 0.875rem;
    }

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

    .footer-col h4 {
      font-size: 1rem;
      color: #0f172a;
      font-weight: 600;
      margin-bottom: 16px;
    }

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

    .footer-links a {
      color: var(--text-muted);
      text-decoration: none;
      transition: var(--transition);
    }

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

    .footer-bottom {
      border-top: 1px solid #f1f5f9;
      padding-top: 24px;
      text-align: center;
      color: #94a3b8;
      font-size: 0.8125rem;
    }

    /* 悬浮客服 */
    .float-service {
      position: fixed;
      right: 24px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #ffffff;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-lg);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      color: var(--primary);
      font-size: 1.25rem;
      transition: var(--transition);
      text-decoration: none;
    }

    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      transform: scale(1.05);
    }

    /* 响应式适配 */
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .step-list { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .hero-title { font-size: 2rem; }
      .hero-stats { grid-template-columns: repeat(2, 1fr); }
      .grid-3, .grid-2, .faq-grid { grid-template-columns: 1fr; }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 16px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active { display: flex; }
      .mobile-menu-btn { display: block; }
      .footer-grid { grid-template-columns: 1fr; }
      .step-list { grid-template-columns: 1fr; }
    }