:root {
      --primary: #2563EB;
      --primary-dark: #1D4ED8;
      --accent: #FF5500;
      --accent-hover: #E04B00;
      --secondary: #7C3AED;
      --bg-light: #F8FAFC;
      --bg-card: #FFFFFF;
      --text-main: #0F172A;
      --text-muted: #475569;
      --border-color: #E2E8F0;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
      --shadow-md: 0 10px 25px -5px rgba(37, 99, 235, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
      --shadow-lg: 0 20px 30px -10px rgba(37, 99, 235, 0.15);
      --shadow-accent: 0 10px 20px -5px rgba(255, 85, 0, 0.3);
      --container-width: 1240px;
    }

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

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

    body {
      background-color: var(--bg-light);
      color: var(--text-main);
      overflow-x: hidden;
    }

    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 20px;
      width: 100%;
    }

    /* 顶部导航 */
    header.site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
    }

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

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

    .logo-box img.ai-page-logo {
      height: 42px;
      width: auto;
      display: block;
    }

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

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

    .nav-links li a {
      display: block;
      padding: 8px 14px;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-muted);
      text-decoration: none;
      transition: all 0.2s ease;
      border-radius: var(--radius-sm);
    }

    .nav-links li a:hover,
    .nav-links li a.ai-page-home-link {
      color: var(--primary);
      background-color: rgba(37, 99, 235, 0.06);
    }

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

    .btn-nav-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 20px;
      font-size: 14px;
      font-weight: 700;
      color: #FFFFFF;
      background: linear-gradient(135deg, var(--accent) 0%, #FF7700 100%);
      border-radius: 50px;
      text-decoration: none;
      box-shadow: var(--shadow-accent);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

    .btn-nav-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 24px -6px rgba(255, 85, 0, 0.4);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      padding: 6px 10px;
      cursor: pointer;
      color: var(--text-main);
    }

    /* 区域统一排版 */
    section {
      padding: 70px 0;
      position: relative;
    }

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

    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary);
      background-color: rgba(37, 99, 235, 0.1);
      border-radius: 50px;
      margin-bottom: 12px;
    }

    .section-badge.badge-accent {
      color: var(--accent);
      background-color: rgba(255, 85, 0, 0.1);
    }

    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 首屏 HERO（禁止任何图片） */
    .hero-section {
      padding: 80px 0 90px;
      background: radial-gradient(circle at 85% 20%, rgba(255, 85, 0, 0.08) 0%, transparent 40%),
                  radial-gradient(circle at 15% 70%, rgba(37, 99, 235, 0.08) 0%, transparent 45%),
                  #FFFFFF;
      border-bottom: 1px solid var(--border-color);
      position: relative;
    }

    .hero-content {
      text-align: center;
      max-width: 900px;
      margin: 0 auto;
    }

    .hero-tag {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: #EFF6FF;
      border: 1px solid #BFDBFE;
      border-radius: 50px;
      font-size: 13px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 24px;
    }

    .hero-tag span.badge-free {
      background: var(--accent);
      color: #fff;
      font-size: 11px;
      padding: 2px 8px;
      border-radius: 20px;
    }

    h1.hero-title {
      font-size: 42px;
      font-weight: 900;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -1px;
    }

    .hero-title .highlight-orange {
      color: var(--accent);
    }

    .hero-title .highlight-blue {
      color: var(--primary);
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
      max-width: 780px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-buttons {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 50px;
    }

    .btn-hero-primary {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 16px 36px;
      font-size: 17px;
      font-weight: 800;
      color: #FFFFFF;
      background: linear-gradient(135deg, var(--accent) 0%, #FF3300 100%);
      border-radius: 50px;
      text-decoration: none;
      box-shadow: 0 12px 28px -6px rgba(255, 85, 0, 0.4);
      transition: all 0.25s ease;
    }

    .btn-hero-primary:hover {
      transform: translateY(-3px) scale(1.02);
      box-shadow: 0 16px 32px -6px rgba(255, 85, 0, 0.5);
    }

    .btn-hero-secondary {
      display: inline-flex;
      align-items: center;
      padding: 16px 32px;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      background: #FFFFFF;
      border: 2px solid var(--border-color);
      border-radius: 50px;
      text-decoration: none;
      transition: all 0.2s ease;
    }

    .btn-hero-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: #F8FAFC;
    }

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

    .metric-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      padding: 22px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      border-top: 4px solid var(--primary);
      transition: transform 0.2s ease;
    }

    .metric-card:nth-child(2) { border-top-color: var(--accent); }
    .metric-card:nth-child(3) { border-top-color: var(--secondary); }
    .metric-card:nth-child(4) { border-top-color: #10B981; }

    .metric-card:hover {
      transform: translateY(-4px);
    }

    .metric-val {
      font-size: 26px;
      font-weight: 900;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .metric-label {
      font-size: 13px;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* 支持模型滚动/矩阵 */
    .model-pills-section {
      background: #FFFFFF;
      padding: 30px 0;
      border-bottom: 1px solid var(--border-color);
    }

    .model-pills-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      justify-content: center;
      align-items: center;
    }

    .model-pill {
      font-size: 12px;
      font-weight: 700;
      padding: 6px 12px;
      background: var(--bg-light);
      border: 1px solid var(--border-color);
      border-radius: 6px;
      color: var(--text-muted);
      transition: all 0.2s ease;
    }

    .model-pill:hover {
      background: var(--primary);
      color: #FFFFFF;
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    /* 网格卡片系统 */
    .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: 28px;
    }

    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
      position: relative;
      overflow: hidden;
    }

    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-color: #CBD5E1;
    }

    .card-icon {
      width: 46px;
      height: 46px;
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 800;
      margin-bottom: 18px;
      background: rgba(37, 99, 235, 0.1);
      color: var(--primary);
    }

    .card-icon.orange {
      background: rgba(255, 85, 0, 0.1);
      color: var(--accent);
    }

    .card-icon.purple {
      background: rgba(124, 58, 237, 0.1);
      color: var(--secondary);
    }

    .card-title {
      font-size: 18px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .card-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      flex-grow: 1;
    }

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

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

    .step-num {
      font-size: 32px;
      font-weight: 900;
      color: var(--accent);
      line-height: 1;
      margin-bottom: 12px;
      opacity: 0.9;
    }

    /* 对比评测表格与卡片 */
    .review-score-hero {
      background: linear-gradient(135deg, #1E293B 0%, #0F172A 100%);
      color: #FFFFFF;
      border-radius: var(--radius-lg);
      padding: 40px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 30px;
      box-shadow: var(--shadow-lg);
    }

    .score-left h3 {
      font-size: 26px;
      font-weight: 800;
      margin-bottom: 8px;
    }

    .score-left p {
      color: #94A3B8;
      font-size: 15px;
    }

    .score-right {
      display: flex;
      align-items: center;
      gap: 24px;
      background: rgba(255, 255, 255, 0.08);
      padding: 16px 28px;
      border-radius: var(--radius-md);
      border: 1px solid rgba(255, 255, 255, 0.15);
    }

    .score-number {
      font-size: 48px;
      font-weight: 900;
      color: var(--accent);
      line-height: 1;
    }

    .score-stars {
      color: #FBBF24;
      font-size: 20px;
      margin-bottom: 4px;
    }

    .comparison-table-wrap {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }

    .comparison-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 14px;
    }

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

    .comparison-table th {
      background: #F1F5F9;
      font-weight: 800;
      color: var(--text-main);
    }

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

    .comparison-table td.highlight-cell {
      background: rgba(37, 99, 235, 0.04);
      font-weight: 700;
      color: var(--primary);
    }

    .badge-check {
      display: inline-block;
      padding: 2px 8px;
      border-radius: 4px;
      font-size: 12px;
      font-weight: 700;
      background: #DCFCE7;
      color: #15803D;
    }

    .badge-cross {
      display: inline-block;
      padding: 2px 8px;
      border-radius: 4px;
      font-size: 12px;
      font-weight: 700;
      background: #FEE2E2;
      color: #B91C1C;
    }

    /* 案例展示画廊 */
    .gallery-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

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

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

    .gallery-img-box {
      width: 100%;
      background: #E2E8F0;
      overflow: hidden;
    }

    .gallery-img-box img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

    .gallery-card:hover .gallery-img-box img {
      transform: scale(1.04);
    }

    .gallery-info {
      padding: 20px;
    }

    .gallery-info h4 {
      font-size: 16px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .gallery-info p {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 用户评论 */
    .testimonial-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 18px;
      position: relative;
    }

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

    .user-avatar-tag {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 15px;
    }

    .user-meta h5 {
      font-size: 14px;
      font-weight: 800;
      color: var(--text-main);
    }

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

    /* FAQ 折叠面板 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      overflow: hidden;
      transition: border-color 0.2s ease;
    }

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

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: color 0.2s ease;
    }

    .faq-question:hover {
      color: var(--primary);
    }

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

    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #F8FAFC;
    }

    .faq-answer-inner {
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    .faq-item.active .faq-answer {
      max-height: 250px;
    }

    /* 表单与转化区 */
    .contact-form-section {
      background: linear-gradient(180deg, #F8FAFC 0%, #EEF2FF 100%);
      border-top: 1px solid var(--border-color);
    }

    .form-wrapper {
      max-width: 760px;
      margin: 0 auto;
      background: #FFFFFF;
      padding: 40px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }

    .form-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 18px;
      margin-bottom: 20px;
    }

    .form-group-full {
      grid-column: 1 / -1;
    }

    .form-label {
      display: block;
      font-size: 13px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      font-size: 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      background: #F8FAFC;
      color: var(--text-main);
      outline: none;
      transition: all 0.2s ease;
    }

    .form-control:focus {
      background: #FFFFFF;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }

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

    .btn-submit {
      width: 100%;
      padding: 15px;
      font-size: 16px;
      font-weight: 800;
      color: #FFFFFF;
      background: linear-gradient(135deg, var(--accent) 0%, #FF3300 100%);
      border: none;
      border-radius: var(--radius-sm);
      cursor: pointer;
      box-shadow: var(--shadow-accent);
      transition: all 0.2s ease;
    }

    .btn-submit:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 24px -5px rgba(255, 85, 0, 0.4);
    }

    /* 资讯与文章列表 */
    .article-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }

    .article-link-tag {
      padding: 10px 18px;
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      text-decoration: none;
      color: var(--text-main);
      font-size: 13px;
      font-weight: 600;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    .article-link-tag:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-2px);
      box-shadow: var(--shadow-sm);
    }

    /* 页脚设计 */
    footer.site-footer {
      background: #0F172A;
      color: #94A3B8;
      padding: 60px 0 30px;
      border-top: 1px solid #1E293B;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-brand h4 {
      font-size: 20px;
      font-weight: 800;
      color: #FFFFFF;
      margin-bottom: 14px;
    }

    .footer-brand p {
      font-size: 14px;
      line-height: 1.7;
      margin-bottom: 16px;
      color: #94A3B8;
    }

    .footer-col h5 {
      font-size: 15px;
      font-weight: 700;
      color: #FFFFFF;
      margin-bottom: 16px;
    }

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

    .footer-links li a {
      color: #94A3B8;
      text-decoration: none;
      font-size: 13px;
      transition: color 0.2s ease;
    }

    .footer-links li a:hover {
      color: #FFFFFF;
    }

    .footer-contact-info {
      font-size: 13px;
      line-height: 1.8;
      color: #94A3B8;
    }

    .footer-qrcode-wrap {
      text-align: left;
    }

    .footer-qrcode-wrap img {
      width: 105px;
      height: 105px;
      border-radius: var(--radius-sm);
      border: 2px solid #334155;
      display: block;
      margin-top: 8px;
    }

    .friendly-links-bar {
      border-top: 1px solid #1E293B;
      padding: 20px 0;
      margin-bottom: 20px;
    }

    .friendly-links-bar span {
      font-size: 13px;
      font-weight: 700;
      color: #E2E8F0;
      margin-right: 12px;
    }

    .friendly-links-bar a {
      color: #94A3B8;
      text-decoration: none;
      font-size: 13px;
      margin-right: 16px;
      display: inline-block;
      transition: color 0.2s ease;
    }

    .friendly-links-bar a:hover {
      color: #FFFFFF;
    }

    .footer-bottom {
      border-top: 1px solid #1E293B;
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: #64748B;
    }

    /* 浮动工具与返回顶部 */
    .floating-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-main);
      font-size: 18px;
      text-decoration: none;
      cursor: pointer;
      transition: all 0.2s ease;
    }

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

    .float-btn.float-cta {
      background: var(--accent);
      color: #FFFFFF;
      border-color: var(--accent);
    }

    /* 响应式优化 */
    @media (max-width: 1024px) {
      .grid-4, .hero-metrics-grid, .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        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.active {
        display: flex;
      }
      .mobile-menu-btn {
        display: block;
      }
      h1.hero-title {
        font-size: 30px;
      }
      .section-title {
        font-size: 26px;
      }
      .grid-3, .gallery-grid, .grid-2 {
        grid-template-columns: 1fr;
      }
      .hero-metrics-grid, .steps-grid {
        grid-template-columns: 1fr;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .review-score-hero {
        flex-direction: column;
        text-align: center;
        gap: 20px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }