:root {
      --primary: #0284c7;
      --primary-hover: #0369a1;
      --primary-light: #e0f2fe;
      --accent: #2563eb;
      --accent-gradient: linear-gradient(135deg, #0284c7 0%, #2563eb 50%, #4f46e5 100%);
      --bg-base: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-sub: #64748b;
      --border-color: #e2e8f0;
      --border-light: #f1f5f9;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
      --shadow-md: 0 4px 12px rgba(2, 132, 199, 0.08), 0 2px 4px rgba(0,0,0,0.03);
      --shadow-lg: 0 12px 30px rgba(2, 132, 199, 0.12), 0 4px 8px rgba(0,0,0,0.04);
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 18px;
      --container-width: 1200px;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

    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-base);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 15px;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: all 0.25s ease;
    }

    .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: 1000;
      background-color: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-wrap {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .ai-page-logo {
      height: 42px;
      width: auto;
      display: block;
    }
    .brand-title {
      font-size: 20px;
      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 {
      display: block;
      padding: 8px 14px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: var(--radius-sm);
    }
    .nav-links li a:hover, .nav-links li a.active {
      color: var(--primary);
      background-color: var(--primary-light);
    }
    .header-action {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      border-radius: var(--radius-md);
      font-size: 14px;
      font-weight: 600;
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--accent-gradient);
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(2, 132, 199, 0.3);
    }
    .btn-primary:hover {
      box-shadow: 0 6px 18px rgba(2, 132, 199, 0.45);
      transform: translateY(-1px);
      color: #ffffff;
    }
    .btn-outline {
      background: #ffffff;
      border-color: var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-lg {
      padding: 13px 30px;
      font-size: 16px;
    }

    .mobile-menu-btn {
      display: none;
      background: transparent;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
      padding: 4px;
    }

    /* 模块通用 */
    section {
      padding: 72px 0;
      position: relative;
    }
    .section-alt {
      background-color: #f1f5f9;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }
    .section-header {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 48px;
    }
    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      background-color: var(--primary-light);
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      border-radius: 20px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.35;
      margin-bottom: 14px;
    }
    .section-subtitle {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 首屏 Hero (无图设计，纯CSS鲜亮光感) */
    .hero-section {
      padding: 80px 0 60px;
      background: radial-gradient(circle at 50% 10%, #dbeafe 0%, #f0f9ff 45%, #f8fafc 90%);
      position: relative;
      overflow: hidden;
      border-bottom: 1px solid var(--border-color);
    }
    .hero-content {
      text-align: center;
      max-width: 880px;
      margin: 0 auto;
      position: relative;
      z-index: 2;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #ffffff;
      padding: 6px 18px;
      border-radius: 30px;
      font-size: 13px;
      font-weight: 600;
      color: var(--primary);
      border: 1px solid #bae6fd;
      box-shadow: var(--shadow-sm);
      margin-bottom: 22px;
    }
    .hero-title {
      font-size: 44px;
      line-height: 1.25;
      font-weight: 800;
      color: #0f172a;
      letter-spacing: -1px;
      margin-bottom: 20px;
    }
    .hero-desc {
      font-size: 17px;
      color: var(--text-muted);
      line-height: 1.65;
      margin-bottom: 32px;
      max-width: 720px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-cta {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }
    .hero-models-pill {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 8px;
      margin-top: 15px;
    }
    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      font-size: 12px;
      color: var(--text-muted);
      padding: 5px 12px;
      border-radius: 16px;
      font-weight: 500;
      box-shadow: 0 1px 2px rgba(0,0,0,0.02);
      transition: all 0.2s;
    }
    .model-chip:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-2px);
    }

    /* 数据指标网格 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 40px;
    }
    .metric-card {
      background: #ffffff;
      padding: 24px 20px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: transform 0.25s, box-shadow 0.25s;
    }
    .metric-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
      border-color: #bae6fd;
    }
    .metric-num {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1;
      margin-bottom: 8px;
    }
    .metric-label {
      font-size: 14px;
      color: var(--text-main);
      font-weight: 600;
      margin-bottom: 4px;
    }
    .metric-desc {
      font-size: 12px;
      color: var(--text-sub);
    }

    /* 卡片网格通用 */
    .cards-grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .cards-grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 26px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
      border-color: #bae6fd;
    }
    .feature-icon-box {
      width: 44px;
      height: 44px;
      border-radius: 10px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
      margin-bottom: 16px;
    }
    .feature-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }
    .feature-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 流程步骤 */
    .process-timeline {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .process-step {
      background: #ffffff;
      padding: 24px 20px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .step-badge {
      display: inline-block;
      background: var(--primary);
      color: #ffffff;
      width: 28px;
      height: 28px;
      line-height: 28px;
      text-align: center;
      border-radius: 50%;
      font-size: 13px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .step-title {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .step-desc {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 对比评测表格与卡片 */
    .review-score-panel {
      background: #ffffff;
      border-radius: var(--radius-lg);
      padding: 30px;
      border: 1px solid #bae6fd;
      box-shadow: var(--shadow-md);
      margin-bottom: 30px;
      display: flex;
      align-items: center;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 20px;
    }
    .score-badge-main {
      text-align: center;
    }
    .score-stars {
      color: #f59e0b;
      font-size: 24px;
      margin-bottom: 4px;
      letter-spacing: 2px;
    }
    .score-big {
      font-size: 48px;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }
    .score-desc {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-top: 6px;
    }
    .table-container {
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }
    .custom-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }
    .custom-table th, .custom-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }
    .custom-table th {
      background-color: #f8fafc;
      color: var(--text-main);
      font-weight: 700;
      font-size: 14px;
    }
    .custom-table tr:last-child td {
      border-bottom: none;
    }
    .custom-table td.highlight {
      background-color: #f0f9ff;
      color: var(--primary);
      font-weight: 600;
    }

    /* 图文与素材展示 */
    .media-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: stretch;
    }
    .media-card {
      background: #ffffff;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
    }
    .media-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #e2e8f0;
      overflow: hidden;
    }
    .media-img-wrap.square {
      aspect-ratio: 1 / 1;
    }
    .media-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s;
    }
    .media-card:hover img {
      transform: scale(1.03);
    }
    .media-info {
      padding: 18px;
      flex-grow: 1;
    }
    .media-title {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 6px;
      color: var(--text-main);
    }
    .media-desc {
      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: 22px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .testimonial-quote {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 16px;
      position: relative;
    }
    .user-profile {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px dashed var(--border-color);
      padding-top: 12px;
    }
    .user-avatar-tag {
      width: 38px;
      height: 38px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
    }
    .user-name {
      font-size: 14px;
      font-weight: 700;
      color: var(--text-main);
    }
    .user-role {
      font-size: 12px;
      color: var(--text-sub);
    }

    /* FAQ 手风琴 */
    .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-md);
      overflow: hidden;
      transition: border-color 0.2s;
    }
    .faq-item.active {
      border-color: var(--primary);
    }
    .faq-question {
      padding: 18px 24px;
      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 0.2s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      padding: 0 24px;
      color: var(--text-muted);
      font-size: 14px;
      line-height: 1.6;
      transition: max-height 0.3s ease, padding 0.3s ease;
    }
    .faq-item.active .faq-answer {
      max-height: 250px;
      padding-bottom: 20px;
    }

    /* 表单与需求匹配 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 32px;
      align-items: start;
    }
    .form-card {
      background: #ffffff;
      border-radius: var(--radius-lg);
      padding: 36px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }
    .form-group {
      margin-bottom: 18px;
    }
    .form-label {
      display: block;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 6px;
    }
    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 14px;
      color: var(--text-main);
      background-color: #f8fafc;
      transition: border-color 0.2s, background-color 0.2s;
    }
    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
    }
    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }
    .contact-info-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .contact-item {
      display: flex;
      gap: 14px;
      margin-bottom: 20px;
    }
    .qr-container {
      text-align: center;
      padding: 16px;
      background: #f8fafc;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      margin-top: 20px;
    }
    .qr-container img {
      max-width: 140px;
      height: auto;
      border-radius: 6px;
      margin-bottom: 8px;
    }

    /* 资讯与友情链接 */
    .article-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 16px;
    }
    .article-link-tag {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: var(--radius-sm);
      font-size: 13px;
      color: var(--text-muted);
    }
    .article-link-tag:hover {
      border-color: var(--primary);
      color: var(--primary);
    }

    /* 页脚 */
    .site-footer {
      background-color: #0f172a;
      color: #94a3b8;
      padding: 56px 0 24px;
      border-top: 1px solid #1e293b;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
      margin-bottom: 40px;
    }
    .footer-title {
      font-size: 15px;
      font-weight: 700;
      color: #f8fafc;
      margin-bottom: 18px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
      font-size: 14px;
    }
    .footer-links a:hover {
      color: #38bdf8;
    }
    .friend-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }
    .friend-links-wrap a {
      background: #1e293b;
      color: #cbd5e1;
      padding: 4px 10px;
      border-radius: 4px;
      font-size: 12px;
    }
    .friend-links-wrap a:hover {
      background: var(--primary);
      color: #ffffff;
    }
    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: #64748b;
    }

    /* 悬浮客服面板 */
    .floating-service {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 990;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
      cursor: pointer;
      border: none;
      font-size: 18px;
      transition: transform 0.2s;
    }
    .float-btn:hover {
      transform: scale(1.1);
    }

    /* 响应式适配 */
    @media (max-width: 1024px) {
      .cards-grid-4, .metrics-grid, .process-timeline {
        grid-template-columns: repeat(2, 1fr);
      }
      .cards-grid-3, .media-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .mobile-menu-btn {
        display: block;
      }
      .nav-links {
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        align-items: stretch;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
        display: none;
        padding: 12px 20px;
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links li a {
        padding: 12px 14px;
      }
      .header-action {
        display: none;
      }
      .hero-title {
        font-size: 30px;
      }
      .hero-desc {
        font-size: 15px;
      }
      .cards-grid-4, .cards-grid-3, .metrics-grid, .process-timeline, .media-grid {
        grid-template-columns: 1fr;
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }