:root {
      --primary: #4F46E5;
      --primary-vivid: #6366F1;
      --secondary: #06B6D4;
      --accent-magenta: #D946EF;
      --accent-amber: #F59E0B;
      --bg-main: #F8FAFC;
      --bg-card: #FFFFFF;
      --bg-alt: #F1F5F9;
      --text-main: #0F172A;
      --text-muted: #475569;
      --text-light: #64748B;
      --border-color: #E2E8F0;
      --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
      --shadow-md: 0 10px 25px -5px rgba(99, 102, 241, 0.12);
      --shadow-hover: 0 20px 35px -10px rgba(99, 102, 241, 0.22);
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-lg: 24px;
      --gradient-vivid: linear-gradient(135deg, #4F46E5 0%, #7C3AED 50%, #D946EF 100%);
      --gradient-cyan: linear-gradient(135deg, #0284C7 0%, #06B6D4 100%);
      --gradient-warm: linear-gradient(135deg, #F59E0B 0%, #EF4444 100%);
      --gradient-card: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
    }

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

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

    body {
      overflow-x: hidden;
      width: 100%;
      background: var(--bg-main);
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
      width: 100%;
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: all 0.25s ease;
    }

    a:hover {
      color: var(--accent-magenta);
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.92);
      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: 76px;
    }

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

    .brand-area img.ai-page-logo {
      height: 42px;
      width: auto;
      object-fit: contain;
    }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 800;
      background: var(--gradient-vivid);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      letter-spacing: -0.5px;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      list-style: none;
    }

    .nav-menu a {
      font-size: 0.95rem;
      font-weight: 600;
      color: var(--text-main);
      padding: 6px 10px;
      border-radius: var(--radius-sm);
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 0.95rem;
      font-weight: 700;
      border-radius: 50px;
      cursor: pointer;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      border: none;
      outline: none;
    }

    .btn-primary {
      background: var(--gradient-vivid);
      color: #FFFFFF !important;
      box-shadow: 0 8px 20px rgba(99, 102, 241, 0.35);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 25px rgba(99, 102, 241, 0.45);
      opacity: 0.95;
    }

    .btn-secondary {
      background: var(--gradient-cyan);
      color: #FFFFFF !important;
      box-shadow: 0 6px 16px rgba(6, 182, 212, 0.3);
    }

    .btn-secondary:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(6, 182, 212, 0.4);
    }

    .btn-outline {
      background: #FFFFFF;
      color: var(--primary) !important;
      border: 2px solid var(--primary);
    }

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

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

    /* 首屏 Hero 区域（严格禁止图片） */
    .hero-section {
      padding: 80px 0 60px;
      background: radial-gradient(circle at 10% 20%, rgba(99, 102, 241, 0.08) 0%, transparent 40%),
                  radial-gradient(circle at 90% 80%, rgba(217, 70, 239, 0.08) 0%, transparent 40%),
                  #FFFFFF;
      border-bottom: 1px solid var(--border-color);
      text-align: center;
      position: relative;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: rgba(99, 102, 241, 0.1);
      border: 1px solid rgba(99, 102, 241, 0.25);
      border-radius: 50px;
      color: var(--primary-vivid);
      font-size: 0.9rem;
      font-weight: 700;
      margin-bottom: 24px;
      animation: pulseGlow 3s infinite alternate;
    }

    @keyframes pulseGlow {
      0% { box-shadow: 0 0 5px rgba(99, 102, 241, 0.2); }
      100% { box-shadow: 0 0 15px rgba(217, 70, 239, 0.4); }
    }

    .hero-title {
      font-size: 2.75rem;
      font-weight: 900;
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
      color: var(--text-main);
    }

    .hero-title span {
      background: var(--gradient-vivid);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-subtitle {
      font-size: 1.15rem;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px;
      font-weight: 500;
    }

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

    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 20px;
      max-width: 1000px;
      margin: 0 auto;
    }

    .metric-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      padding: 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s ease;
    }

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

    .metric-num {
      font-size: 2rem;
      font-weight: 900;
      color: var(--primary-vivid);
      margin-bottom: 4px;
    }

    .metric-label {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* 区块通用样式 */
    .section-padding {
      padding: 80px 0;
    }

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

    .section-tag {
      font-size: 0.85rem;
      font-weight: 800;
      text-transform: uppercase;
      letter-spacing: 1.5px;
      color: var(--accent-magenta);
      margin-bottom: 8px;
      display: block;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.3;
    }

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

    /* 关于我们 & 平台介绍 */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .about-content {
      background: #FFFFFF;
      padding: 36px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }

    .about-content h3 {
      font-size: 1.5rem;
      margin-bottom: 16px;
      color: var(--text-main);
    }

    .about-content p {
      color: var(--text-muted);
      margin-bottom: 20px;
      font-size: 0.98rem;
    }

    .about-feature-list {
      list-style: none;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
    }

    .about-feature-item {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.9rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .about-feature-item::before {
      content: "✓";
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 22px;
      height: 22px;
      background: rgba(6, 182, 212, 0.15);
      color: var(--secondary);
      border-radius: 50%;
      font-size: 0.8rem;
      font-weight: 900;
    }

    /* 模型与服务网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }

    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: all 0.3s ease;
      position: relative;
      overflow: hidden;
    }

    .service-card::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 4px;
      background: var(--gradient-vivid);
      opacity: 0;
      transition: opacity 0.3s ease;
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(99, 102, 241, 0.3);
    }

    .service-card:hover::before {
      opacity: 1;
    }

    .service-icon-box {
      width: 54px;
      height: 54px;
      border-radius: 14px;
      background: rgba(99, 102, 241, 0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      color: var(--primary);
      margin-bottom: 20px;
    }

    .service-card h4 {
      font-size: 1.25rem;
      margin-bottom: 12px;
      color: var(--text-main);
    }

    .service-card p {
      font-size: 0.92rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 标签云模型墙 */
    .model-tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-tag {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: 50px;
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: 0 2px 4px rgba(0,0,0,0.02);
      transition: all 0.2s ease;
    }

    .model-tag:hover {
      background: var(--primary-vivid);
      color: #FFFFFF;
      border-color: var(--primary-vivid);
      transform: scale(1.05);
    }

    /* 对比评测表格 */
    .comparison-wrapper {
      background: #FFFFFF;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
      overflow-x: auto;
      margin-bottom: 40px;
    }

    .comparison-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 650px;
    }

    .comparison-table th, .comparison-table td {
      padding: 18px 24px;
      border-bottom: 1px solid var(--border-color);
    }

    .comparison-table th {
      background: #F8FAFC;
      font-size: 0.95rem;
      font-weight: 800;
      color: var(--text-main);
    }

    .comparison-table th.highlight {
      background: rgba(99, 102, 241, 0.08);
      color: var(--primary);
    }

    .comparison-table td.highlight {
      background: rgba(99, 102, 241, 0.03);
      font-weight: 700;
      color: var(--text-main);
    }

    .rating-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: var(--gradient-warm);
      color: #FFFFFF;
      padding: 6px 14px;
      border-radius: 50px;
      font-weight: 800;
      font-size: 0.9rem;
    }

    /* 标准化流程 & 解决方案 */
    .workflow-steps {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
      position: relative;
    }

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

    .step-number {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--gradient-vivid);
      color: #FFFFFF;
      font-weight: 900;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
    }

    .step-card h5 {
      font-size: 1.1rem;
      margin-bottom: 8px;
    }

    .step-card p {
      font-size: 0.88rem;
      color: var(--text-muted);
    }

    /* Token 比价与智能计算 */
    .token-calculator-card {
      background: var(--gradient-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-md);
    }

    .calc-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }

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

    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 700;
      margin-bottom: 8px;
      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: #FFFFFF;
      color: var(--text-main);
    }

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

    /* 培训板块 */
    .training-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
    }

    .course-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s;
    }

    .course-card:hover {
      transform: translateY(-5px);
      border-color: var(--secondary);
    }

    .course-icon {
      font-size: 2rem;
      margin-bottom: 12px;
    }

    .course-card h4 {
      font-size: 1.05rem;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .course-tag {
      display: inline-block;
      padding: 4px 10px;
      background: rgba(6, 182, 212, 0.1);
      color: var(--secondary);
      font-size: 0.75rem;
      font-weight: 800;
      border-radius: 4px;
      margin-bottom: 12px;
    }

    /* 案例展示区 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

    .case-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

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

    .case-img-box img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

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

    .case-content {
      padding: 20px;
    }

    .case-content h4 {
      font-size: 1.1rem;
      margin-bottom: 8px;
    }

    .case-content p {
      font-size: 0.88rem;
      color: var(--text-muted);
    }

    /* 客户评价 */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 24px;
    }

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

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

    .avatar-placeholder {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--gradient-vivid);
      color: #FFFFFF;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
    }

    .user-info h5 {
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .user-info span {
      font-size: 0.8rem;
      color: var(--text-light);
    }

    .review-text {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-style: italic;
    }

    /* FAQ 折叠面板 */
    .faq-accordion {
      max-width: 900px;
      margin: 0 auto;
    }

    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-header {
      padding: 18px 24px;
      font-weight: 700;
      font-size: 1rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      color: var(--text-main);
      background: #FFFFFF;
      transition: background 0.2s;
    }

    .faq-header:hover {
      background: #F8FAFC;
    }

    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.3s ease;
    }

    .faq-body {
      padding: 0 24px 20px;
      font-size: 0.92rem;
      color: var(--text-muted);
      display: none;
      border-top: 1px solid transparent;
    }

    .faq-item.active .faq-body {
      display: block;
      border-top-color: var(--border-color);
    }

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

    /* 表单与联系 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }

    .contact-info h3 {
      font-size: 1.6rem;
      margin-bottom: 16px;
    }

    .contact-info p {
      color: var(--text-muted);
      margin-bottom: 24px;
      font-size: 0.95rem;
    }

    .info-list-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .qr-box {
      margin-top: 24px;
      text-align: center;
      display: inline-block;
      padding: 12px;
      background: #F8FAFC;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
    }

    .qr-box img {
      width: 130px;
      height: 130px;
      object-fit: cover;
      display: block;
      margin: 0 auto 8px;
    }

    .qr-box span {
      font-size: 0.8rem;
      font-weight: 700;
      color: var(--text-muted);
    }

    /* 知识库与友情链接区 */
    .links-block {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      margin-top: 40px;
    }

    .links-title {
      font-size: 1rem;
      font-weight: 800;
      margin-bottom: 16px;
      color: var(--text-main);
    }

    .links-flex {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
    }

    .links-flex a {
      font-size: 0.88rem;
      color: var(--text-muted);
      background: #F1F5F9;
      padding: 6px 12px;
      border-radius: 4px;
    }

    .links-flex a:hover {
      background: var(--primary);
      color: #FFFFFF;
    }

    /* 页脚 */
    .site-footer {
      background: #0F172A;
      color: #94A3B8;
      padding: 50px 0 30px;
      border-top: 1px solid #1E293B;
      font-size: 0.9rem;
    }

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

    .footer-brand h4 {
      color: #FFFFFF;
      font-size: 1.3rem;
      margin-bottom: 12px;
    }

    .footer-brand p {
      font-size: 0.88rem;
      line-height: 1.7;
    }

    .footer-links h5 {
      color: #FFFFFF;
      font-size: 1rem;
      margin-bottom: 16px;
    }

    .footer-links ul {
      list-style: none;
    }

    .footer-links ul li {
      margin-bottom: 8px;
    }

    .footer-links ul li a {
      color: #94A3B8;
    }

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

    .footer-bottom {
      border-top: 1px solid #1E293B;
      padding-top: 24px;
      text-align: center;
      font-size: 0.85rem;
    }

    .ai-page-home-link {
      color: var(--primary);
      font-weight: 700;
    }

    /* 响应式适配 */
    @media (max-width: 992px) {
      .hero-title { font-size: 2.2rem; }
      .about-grid, .calc-grid, .contact-wrapper { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 76px;
        left: 0;
        width: 100%;
        background: #FFFFFF;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-menu.active { display: flex; }
      .mobile-toggle { display: block; }
      .hero-title { font-size: 1.8rem; }
      .hero-section { padding: 50px 0 40px; }
      .section-padding { padding: 50px 0; }
    }