:root {
      --primary: #4338ca;
      --primary-light: #6366f1;
      --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #db2777 100%);
      --accent-rainbow: linear-gradient(120deg, #ec4899, #8b5cf6, #3b82f6, #10b981, #f59e0b);
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --bg-soft: #f1f5f9;
      --text-main: #0f172a;
      --text-sub: #334155;
      --text-muted: #64748b;
      --border-color: #e2e8f0;
      --border-focus: #818cf8;
      --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.06);
      --shadow-md: 0 4px 20px -2px rgba(99, 102, 241, 0.08);
      --shadow-lg: 0 12px 30px -4px rgba(79, 70, 229, 0.12);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --transition: all 0.28s ease;
    }

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

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      background-image: 
        radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.06) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(236, 72, 153, 0.06) 0px, transparent 50%),
        radial-gradient(at 50% 50%, rgba(16, 185, 129, 0.03) 0px, transparent 50%);
      background-attachment: fixed;
    }

    .container {
      width: 100%;
      max-width: 1240px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      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-box {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
    }

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

    .brand-title {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

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

    .nav-links li a {
      display: block;
      padding: 8px 14px;
      color: var(--text-sub);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.92rem;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }

    .nav-links li a:hover {
      color: var(--primary);
      background: rgba(99, 102, 241, 0.08);
    }

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 20px;
      font-size: 0.95rem;
      font-weight: 600;
      text-decoration: none;
      border-radius: var(--radius-md);
      transition: var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      line-height: 1.2;
    }

    .btn-primary {
      background: var(--primary-gradient);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(79, 70, 229, 0.35);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(79, 70, 229, 0.45);
    }

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

    .btn-secondary:hover {
      background: #f8fafc;
      transform: translateY(-2px);
    }

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

    /* 斑斓色彩装饰条与徽章 */
    .rainbow-tag {
      display: inline-flex;
      align-items: center;
      padding: 6px 14px;
      border-radius: 9999px;
      font-size: 0.85rem;
      font-weight: 700;
      background: linear-gradient(90deg, #fce7f3, #ede9fe, #e0e7ff, #d1fae5);
      color: var(--primary);
      border: 1px solid rgba(167, 139, 250, 0.4);
      margin-bottom: 16px;
    }

    /* Section 通用规范 */
    .section-wrap {
      padding: 80px 0;
      position: relative;
    }

    .section-head {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 50px auto;
    }

    .section-head h2 {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 12px;
      letter-spacing: -0.5px;
    }

    .section-head p {
      color: var(--text-muted);
      font-size: 1.05rem;
    }

    /* Hero 首屏 (无图片，纯几何渐变与卡片排版) */
    .hero-section {
      padding: 70px 0 60px 0;
      background: radial-gradient(circle at 50% 20%, rgba(99, 102, 241, 0.08) 0%, rgba(248, 250, 252, 0) 70%);
      border-bottom: 1px solid var(--border-color);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 40px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 2.4rem;
      line-height: 1.25;
      font-weight: 900;
      color: var(--text-main);
      margin-bottom: 18px;
    }

    .hero-desc {
      font-size: 1.12rem;
      color: var(--text-sub);
      margin-bottom: 28px;
      line-height: 1.7;
    }

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
      margin-bottom: 30px;
    }

    .hero-highlights {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .highlight-item {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    .highlight-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #10b981;
    }

    .hero-showcase {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: var(--shadow-lg);
      position: relative;
    }

    .hero-showcase::before {
      content: "";
      position: absolute;
      top: -2px;
      left: 20px;
      right: 20px;
      height: 4px;
      background: var(--accent-rainbow);
      border-radius: 4px 4px 0 0;
    }

    .hero-card-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
    }

    .stat-box {
      background: var(--bg-soft);
      padding: 16px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
    }

    .stat-box .stat-label {
      font-size: 0.85rem;
      color: var(--text-muted);
      margin-bottom: 4px;
    }

    .stat-box .stat-val {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--primary);
    }

    .stat-box .stat-desc {
      font-size: 0.78rem;
      color: var(--text-sub);
      margin-top: 4px;
    }

    /* 平台核心模型矩阵 */
    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 24px;
    }

    .model-pill {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--text-sub);
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }

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

    /* 卡片网格通用 */
    .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: 24px;
    }

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

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

    .card-badge {
      align-self: flex-start;
      font-size: 0.75rem;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 6px;
      background: rgba(99, 102, 241, 0.1);
      color: var(--primary);
      margin-bottom: 14px;
    }

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

    .feature-card p {
      font-size: 0.94rem;
      color: var(--text-sub);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 流程步骤 */
    .step-list {
      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-lg);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--primary-gradient);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin-bottom: 16px;
    }

    .step-card h3 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .step-card p {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* 案例展示区 (图文布局) */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      background: var(--bg-soft);
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.4s ease;
    }

    .case-card:hover .case-img-wrap img {
      transform: scale(1.05);
    }

    .case-body {
      padding: 20px;
      flex-grow: 1;
      display: flex;
      flex-direction: column;
    }

    .case-body h3 {
      font-size: 1.15rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .case-body p {
      font-size: 0.9rem;
      color: var(--text-sub);
      line-height: 1.55;
    }

    /* 对比评测板块 */
    .review-summary-card {
      background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
      border: 1px solid var(--border-focus);
      border-radius: var(--radius-lg);
      padding: 30px;
      box-shadow: var(--shadow-md);
      margin-bottom: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }

    .review-score-box {
      display: flex;
      align-items: baseline;
      gap: 10px;
    }

    .score-large {
      font-size: 3.2rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }

    .score-max {
      font-size: 1.2rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    .star-rating {
      color: #f59e0b;
      font-size: 1.4rem;
      letter-spacing: 2px;
    }

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

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

    .comparison-table th, 
    .comparison-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.94rem;
    }

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

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

    .highlight-col {
      background: rgba(99, 102, 241, 0.03);
      font-weight: 600;
      color: var(--primary);
    }

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

    .testimonial-body {
      font-size: 0.94rem;
      color: var(--text-sub);
      line-height: 1.6;
      margin-bottom: 16px;
      font-style: italic;
    }

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

    .user-meta h4 {
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .user-meta span {
      font-size: 0.82rem;
      color: var(--text-muted);
    }

    /* FAQ 折叠面板 */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

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

    .faq-header {
      padding: 18px 22px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-weight: 700;
      color: var(--text-main);
      font-size: 1.02rem;
    }

    .faq-header::after {
      content: "+";
      font-size: 1.3rem;
      color: var(--primary);
      transition: transform 0.2s ease;
    }

    .faq-item.active .faq-header::after {
      content: "-";
    }

    .faq-content {
      padding: 0 22px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      color: var(--text-sub);
      font-size: 0.94rem;
      line-height: 1.65;
    }

    .faq-item.active .faq-content {
      padding: 0 22px 18px 22px;
      max-height: 300px;
    }

    /* 表单与需求接入 */
    .form-box-wrapper {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-lg);
      max-width: 760px;
      margin: 0 auto;
    }

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

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 600;
      font-size: 0.92rem;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      background: #fdfdfd;
      color: var(--text-main);
      transition: var(--transition);
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary-light);
      box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
      background: #ffffff;
    }

    textarea.form-control {
      min-height: 120px;
      resize: vertical;
    }

    /* 资讯与百科 */
    .article-pill-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 14px 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      text-decoration: none;
      color: var(--text-main);
      font-weight: 500;
      transition: var(--transition);
    }

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

    /* 联系我们与客服展示 */
    .contact-card-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      align-items: center;
    }

    .qr-box-wrap {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 30px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    .qr-box-wrap img {
      max-width: 180px;
      height: auto;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      margin-bottom: 14px;
    }

    /* 友情链接与页脚 */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 50px 0 30px 0;
      color: var(--text-sub);
    }

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

    .footer-col h4 {
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .friend-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
    }

    .friend-links-wrap a {
      color: var(--text-sub);
      text-decoration: none;
      font-size: 0.88rem;
      background: var(--bg-soft);
      padding: 4px 10px;
      border-radius: 4px;
      border: 1px solid var(--border-color);
      transition: var(--transition);
    }

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

    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.86rem;
      color: var(--text-muted);
      flex-wrap: wrap;
      gap: 12px;
    }

    /* 悬浮客服挂件 */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 999;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 9999px;
      padding: 8px 16px;
      box-shadow: var(--shadow-lg);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      color: var(--text-main);
      font-weight: 700;
      font-size: 0.88rem;
      transition: var(--transition);
    }

    .floating-kefu:hover {
      transform: translateY(-3px);
      box-shadow: 0 10px 25px rgba(99, 102, 241, 0.25);
    }

    .floating-dot {
      width: 10px;
      height: 10px;
      background: #10b981;
      border-radius: 50%;
    }

    /* 响应式适配 */
    @media (max-width: 992px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .grid-3, .grid-4, .case-grid, .step-list {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-top {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
      }

      .nav-links.active {
        display: flex;
      }

      .mobile-menu-btn {
        display: block;
      }

      .grid-3, .grid-4, .grid-2, .case-grid, .step-list, .contact-card-grid {
        grid-template-columns: 1fr;
      }

      .hero-content h1 {
        font-size: 1.85rem;
      }

      .footer-top {
        grid-template-columns: 1fr;
      }

      .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
      }
    }