:root {
      --primary: #1d4ed8;
      --primary-hover: #1e40af;
      --primary-light: #eff6ff;
      --primary-border: #bfdbfe;
      --accent: #2563eb;
      --accent-glow: rgba(37, 99, 235, 0.15);
      --dark: #0f172a;
      --text-main: #1e293b;
      --text-sub: #475569;
      --text-light: #64748b;
      --bg-main: #ffffff;
      --bg-alt: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.06);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
      --shadow-glow: 0 10px 25px -5px rgba(29, 78, 216, 0.15);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --radius-full: 9999px;
      --max-width: 1200px;
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    .container {
      width: 100%;
      max-width: var(--max-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: 1000;
      background-color: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.03);
    }

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

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

    .ai-page-logo {
      height: 38px;
      width: auto;
      object-fit: contain;
    }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.02em;
    }

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

    .nav-item a {
      padding: 8px 14px;
      font-size: 0.938rem;
      font-weight: 500;
      color: var(--text-sub);
      border-radius: var(--radius-sm);
    }

    .nav-item 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-weight: 600;
      font-size: 0.938rem;
      padding: 10px 20px;
      border-radius: var(--radius-md);
      transition: var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff !important;
      box-shadow: 0 4px 12px rgba(29, 78, 216, 0.25);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 6px 16px rgba(29, 78, 216, 0.35);
      transform: translateY(-1px);
    }

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

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

    .btn-lg {
      padding: 14px 28px;
      font-size: 1.05rem;
    }

    .nav-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
      padding: 6px;
    }

    /* 区域通用样式 */
    .section {
      padding: 80px 0;
      position: relative;
    }

    .section-alt {
      background-color: var(--bg-alt);
    }

    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 50px auto;
    }

    .section-tag {
      display: inline-block;
      font-size: 0.813rem;
      font-weight: 700;
      color: var(--primary);
      background-color: var(--primary-light);
      border: 1px solid var(--primary-border);
      padding: 4px 12px;
      border-radius: var(--radius-full);
      margin-bottom: 12px;
      letter-spacing: 0.05em;
      text-transform: uppercase;
    }

    .section-title {
      font-size: 2.125rem;
      font-weight: 800;
      color: var(--dark);
      letter-spacing: -0.02em;
      margin-bottom: 16px;
    }

    .section-desc {
      font-size: 1.05rem;
      color: var(--text-sub);
      line-height: 1.6;
    }

    /* 首屏 Hero */
    .hero-section {
      padding: 90px 0 70px 0;
      background: radial-gradient(circle at 50% 0%, #eff6ff 0%, #ffffff 70%);
      border-bottom: 1px solid var(--border-color);
      text-align: center;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background-color: #ffffff;
      border: 1px solid var(--primary-border);
      padding: 6px 16px;
      border-radius: var(--radius-full);
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
    }

    .hero-title {
      font-size: 2.85rem;
      font-weight: 900;
      color: var(--dark);
      line-height: 1.25;
      margin-bottom: 24px;
      letter-spacing: -0.03em;
    }

    .hero-title .highlight {
      color: var(--primary);
      background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-lead {
      font-size: 1.2rem;
      color: var(--text-sub);
      max-width: 820px;
      margin: 0 auto 36px auto;
      line-height: 1.7;
    }

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

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

    .highlight-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 24px 20px;
      text-align: left;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .highlight-card:hover {
      border-color: var(--primary-border);
      box-shadow: var(--shadow-glow);
      transform: translateY(-3px);
    }

    .highlight-num {
      font-size: 1.85rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1;
      margin-bottom: 8px;
    }

    .highlight-label {
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 4px;
    }

    .highlight-text {
      font-size: 0.85rem;
      color: var(--text-light);
    }

    /* 支持模型滚动/标签云 */
    .models-bar {
      margin-top: 40px;
      padding: 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .models-label {
      font-size: 0.85rem;
      font-weight: 700;
      color: var(--text-light);
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }

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

    .model-tag {
      background-color: var(--bg-alt);
      border: 1px solid var(--border-color);
      color: var(--text-main);
      font-size: 0.813rem;
      font-weight: 500;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }

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

    /* 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: 30px;
    }

    .feature-card {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      height: 100%;
    }

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

    .feature-icon {
      width: 46px;
      height: 46px;
      border-radius: var(--radius-md);
      background-color: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.15rem;
      margin-bottom: 18px;
    }

    .feature-card h3 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 10px;
    }

    .feature-card p {
      font-size: 0.938rem;
      color: var(--text-sub);
      line-height: 1.6;
      flex-grow: 1;
    }

    .feature-badge {
      align-self: flex-start;
      margin-top: 16px;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: var(--radius-sm);
      background-color: var(--bg-alt);
      color: var(--primary);
      border: 1px solid var(--border-color);
    }

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

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

    .step-index {
      width: 36px;
      height: 36px;
      background-color: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin-bottom: 16px;
      box-shadow: 0 2px 8px rgba(29, 78, 216, 0.3);
    }

    .step-item h4 {
      font-size: 1.125rem;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--dark);
    }

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

    /* 评测与对比板块 */
    .review-score-panel {
      background: linear-gradient(135deg, #1d4ed8 0%, #1e3a8a 100%);
      color: #ffffff;
      border-radius: var(--radius-lg);
      padding: 40px;
      margin-bottom: 40px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 24px;
      box-shadow: var(--shadow-lg);
    }

    .score-left h3 {
      font-size: 1.75rem;
      font-weight: 800;
      margin-bottom: 8px;
    }

    .score-left p {
      color: #bfdbfe;
      font-size: 0.95rem;
      max-width: 580px;
    }

    .score-right {
      display: flex;
      align-items: center;
      gap: 24px;
      background: rgba(255, 255, 255, 0.1);
      padding: 20px 30px;
      border-radius: var(--radius-md);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255, 255, 255, 0.2);
    }

    .score-stars {
      color: #facc15;
      font-size: 1.5rem;
      letter-spacing: 2px;
    }

    .score-number {
      font-size: 2.75rem;
      font-weight: 900;
      line-height: 1;
    }

    .score-total {
      font-size: 1rem;
      color: #bfdbfe;
      font-weight: normal;
    }

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

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.938rem;
    }

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

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

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

    .compare-table td.primary-cell {
      background-color: rgba(239, 246, 255, 0.5);
      color: var(--primary);
      font-weight: 700;
    }

    .badge-check {
      color: #16a34a;
      font-weight: 700;
    }

    .badge-cross {
      color: #94a3b8;
    }

    /* 案例展示区图片容器 */
    .media-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .media-img-wrap {
      aspect-ratio: 16 / 9;
      background-color: var(--bg-alt);
      overflow: hidden;
    }

    .media-img-wrap.square {
      aspect-ratio: 1 / 1;
    }

    .media-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }

    .media-card:hover .media-img-wrap img {
      transform: scale(1.03);
    }

    .media-body {
      padding: 20px;
    }

    .media-body h4 {
      font-size: 1.125rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 6px;
    }

    .media-body p {
      font-size: 0.875rem;
      color: var(--text-sub);
    }

    /* 评论卡片 */
    .review-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      height: 100%;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .review-card:hover {
      border-color: var(--primary-border);
      box-shadow: var(--shadow-glow);
    }

    .review-stars {
      color: #f59e0b;
      margin-bottom: 12px;
      font-size: 0.875rem;
    }

    .review-content {
      font-size: 0.938rem;
      color: var(--text-sub);
      line-height: 1.6;
      margin-bottom: 18px;
    }

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

    .avatar-circle {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background-color: var(--primary-light);
      color: var(--primary);
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.95rem;
    }

    .author-info h5 {
      font-size: 0.938rem;
      font-weight: 700;
      color: var(--dark);
    }

    .author-info span {
      font-size: 0.813rem;
      color: var(--text-light);
    }

    /* 折叠面板 (FAQ) */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

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

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

    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      font-size: 1.05rem;
      color: var(--dark);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      user-select: none;
    }

    .faq-icon {
      font-size: 1.25rem;
      color: var(--primary);
      transition: transform 0.25s ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background-color: var(--bg-alt);
    }

    .faq-answer-inner {
      padding: 18px 24px;
      font-size: 0.938rem;
      color: var(--text-sub);
      line-height: 1.7;
      border-top: 1px solid var(--border-color);
    }

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

    .form-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
      text-align: left;
    }

    .form-group.full-width {
      grid-column: span 2;
    }

    .form-label {
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--dark);
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      font-size: 0.938rem;
      color: var(--text-main);
      background-color: var(--bg-alt);
      outline: none;
      transition: var(--transition);
      font-family: inherit;
    }

    .form-control:focus {
      background-color: #ffffff;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.12);
    }

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

    /* 文章链接列表与聚合条目 */
    .article-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      transition: var(--transition);
    }

    .article-item:hover {
      border-color: var(--primary);
      background-color: var(--primary-light);
    }

    .article-title {
      font-weight: 600;
      color: var(--text-main);
      font-size: 0.95rem;
    }

    .article-tag {
      font-size: 0.75rem;
      background: var(--bg-alt);
      padding: 2px 8px;
      border-radius: var(--radius-sm);
      color: var(--text-light);
    }

    /* 友情链接与生态 */
    .friendly-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }

    .friendly-links-wrap a {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: var(--radius-sm);
      font-size: 0.875rem;
      color: var(--text-sub);
    }

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

    /* 联系我们与客服卡片 */
    .contact-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      height: 100%;
      text-align: left;
    }

    .contact-card h4 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 16px;
    }

    .contact-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .contact-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      font-size: 0.938rem;
      color: var(--text-sub);
    }

    .contact-label {
      font-weight: 700;
      color: var(--dark);
      min-width: 80px;
    }

    .qr-box {
      width: 130px;
      height: 130px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      padding: 4px;
      background: #ffffff;
      margin-top: 12px;
    }

    .qr-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* 页脚 */
    .site-footer {
      background-color: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px 0;
      font-size: 0.938rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 36px;
      padding-bottom: 40px;
      border-bottom: 1px solid #1e293b;
    }

    .footer-brand h4 {
      color: #ffffff;
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 14px;
    }

    .footer-brand p {
      line-height: 1.7;
      margin-bottom: 20px;
      font-size: 0.875rem;
      max-width: 320px;
    }

    .footer-col h5 {
      color: #ffffff;
      font-size: 1rem;
      font-weight: 700;
      margin-bottom: 18px;
    }

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

    .footer-links a {
      color: #94a3b8;
      font-size: 0.875rem;
    }

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

    .footer-bottom {
      padding-top: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.813rem;
      color: #64748b;
    }

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

    .float-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background-color: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 14px rgba(29, 78, 216, 0.4);
      cursor: pointer;
      transition: var(--transition);
      border: none;
      font-size: 1.25rem;
    }

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

    .float-qr-modal {
      position: absolute;
      right: 60px;
      bottom: 0;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 16px;
      box-shadow: var(--shadow-lg);
      display: none;
      width: 180px;
      text-align: center;
    }

    .float-qr-modal.show {
      display: block;
    }

    .float-qr-modal p {
      font-size: 0.813rem;
      color: var(--text-main);
      font-weight: 600;
      margin-top: 8px;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .hero-highlights {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .step-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background-color: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-toggle {
        display: block;
      }
      .hero-title {
        font-size: 2.1rem;
      }
      .grid-3,
      .grid-2 {
        grid-template-columns: 1fr;
      }
      .step-timeline {
        grid-template-columns: 1fr;
      }
      .hero-highlights {
        grid-template-columns: 1fr;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .form-group.full-width {
        grid-column: span 1;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .review-score-panel {
        flex-direction: column;
        align-items: flex-start;
      }
      .score-right {
        width: 100%;
        justify-content: space-between;
      }
    }