:root {
      --primary: #4f46e5;
      --primary-dark: #4338ca;
      --secondary: #ff4757;
      --accent: #f59e0b;
      --teal: #0d9488;
      --bg-base: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --border-color: #e2e8f0;
      --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
      --shadow-md: 0 10px 25px -5px rgba(79, 70, 229, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
      --shadow-hover: 0 20px 30px -10px rgba(79, 70, 229, 0.2);
      --radius: 12px;
      --container-width: 1280px;
    }

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

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

    body {
      overflow-x: hidden;
      background: linear-gradient(180deg, #f1f5f9 0%, #f8fafc 100%);
    }

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

    a:hover {
      color: var(--primary-dark);
    }

    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 2px solid #e0e7ff;
      box-shadow: var(--shadow-sm);
    }

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

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

    .brand-zone img.ai-page-logo {
      height: 42px;
      width: auto;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0; /* 严格符合控制描述要求 */
      list-style: none;
    }

    .nav-links li a {
      display: inline-block;
      padding: 8px 12px;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      border-radius: 6px;
    }

    .nav-links li a:hover {
      background: #eff6ff;
      color: var(--primary);
    }

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 15px;
      font-weight: 700;
      border-radius: 8px;
      cursor: pointer;
      border: 2px solid transparent;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      text-align: center;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, #3730a3 100%);
      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-accent {
      background: linear-gradient(135deg, var(--secondary) 0%, #d97706 100%);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(255, 71, 87, 0.3);
    }

    .btn-accent:hover {
      transform: translateY(-2px);
    }

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

    .btn-outline:hover {
      background: #e0e7ff;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      cursor: pointer;
      color: var(--text-main);
    }

    /* 通用 Section 样式 */
    section {
      padding: 70px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      background: #e0e7ff;
      color: var(--primary-dark);
      border-radius: 20px;
      font-size: 13px;
      font-weight: 700;
      margin-bottom: 12px;
      letter-spacing: 1px;
    }

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

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 720px;
      margin: 12px auto 0 auto;
    }

    /* 首屏 HERO 区域 - 严禁出现图片 */
    .hero-section {
      background: linear-gradient(135deg, #ffffff 0%, #eef2ff 50%, #e0e7ff 100%);
      padding: 90px 0 70px 0;
      border-bottom: 3px solid #c7d2fe;
    }

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

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: #ffedd5;
      border: 1px solid #fde68a;
      color: #9a3412;
      border-radius: 30px;
      font-size: 14px;
      font-weight: 700;
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 42px;
      line-height: 1.25;
      font-weight: 900;
      color: #1e1b4b;
      margin-bottom: 20px;
    }

    .hero-subtitle {
      font-size: 19px;
      color: var(--text-muted);
      margin-bottom: 36px;
      line-height: 1.7;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .hero-actions .btn {
      padding: 14px 36px;
      font-size: 17px;
    }

    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 30px;
      background: #ffffff;
      padding: 24px;
      border-radius: 16px;
      box-shadow: var(--shadow-md);
      border: 1px solid #c7d2fe;
    }

    .metric-item {
      text-align: center;
      border-right: 1px solid var(--border-color);
    }

    .metric-item:last-child {
      border-right: none;
    }

    .metric-num {
      font-size: 30px;
      font-weight: 900;
      color: var(--primary);
      font-family: Impact, sans-serif;
    }

    .metric-label {
      font-size: 14px;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* 关于我们 */
    .about-card {
      background: var(--bg-card);
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-md);
      border-left: 6px solid var(--primary);
    }

    .model-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 20px;
    }

    .model-tag {
      background: #f1f5f9;
      color: #334155;
      padding: 6px 14px;
      border-radius: 6px;
      font-size: 13px;
      font-weight: 600;
      border: 1px solid #cbd5e1;
    }

    /* AIGC 服务能力 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
      gap: 24px;
    }

    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      transition: all 0.3s ease;
      position: relative;
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }

    .service-icon {
      width: 48px;
      height: 48px;
      background: #e0e7ff;
      color: var(--primary);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: 800;
      margin-bottom: 16px;
    }

    .service-card h3 {
      font-size: 18px;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .service-card p {
      font-size: 14px;
      color: var(--text-muted);
    }

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

    .step-card {
      background: #ffffff;
      padding: 28px 20px;
      border-radius: var(--radius);
      border-top: 4px solid var(--accent);
      box-shadow: var(--shadow-sm);
      position: relative;
    }

    .step-idx {
      font-size: 36px;
      font-weight: 900;
      color: #fde68a;
      line-height: 1;
      margin-bottom: 10px;
    }

    /* 对比评测表格 */
    .comp-container {
      background: #ffffff;
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-md);
      border: 2px solid #e0e7ff;
    }

    .rating-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: linear-gradient(90deg, #1e1b4b 0%, #312e81 100%);
      color: #ffffff;
      padding: 20px 30px;
      border-radius: 10px;
      margin-bottom: 24px;
    }

    .rating-score {
      font-size: 32px;
      font-weight: 900;
      color: var(--accent);
    }

    .comp-table {
      width: 100%;
      border-collapse: collapse;
      margin-top: 10px;
    }

    .comp-table th, .comp-table td {
      padding: 16px;
      text-align: left;
      border-bottom: 1px solid var(--border-color);
    }

    .comp-table th {
      background: #f8fafc;
      font-weight: 700;
      color: var(--text-main);
    }

    .comp-highlight {
      background: #eff6ff;
      font-weight: 700;
      color: var(--primary);
    }

    /* Token 比价 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 24px;
    }

    .pricing-card {
      background: #ffffff;
      border-radius: var(--radius);
      padding: 28px;
      border: 2px solid var(--border-color);
      text-align: center;
      position: relative;
    }

    .pricing-card.popular {
      border-color: var(--secondary);
      box-shadow: var(--shadow-hover);
    }

    .pricing-badge {
      position: absolute;
      top: -12px;
      right: 20px;
      background: var(--secondary);
      color: #ffffff;
      font-size: 12px;
      font-weight: 700;
      padding: 2px 10px;
      border-radius: 10px;
    }

    .price-num {
      font-size: 34px;
      font-weight: 900;
      color: var(--text-main);
      margin: 16px 0;
    }

    /* FAQ 折叠面板 */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 10px;
      overflow: hidden;
    }

    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      font-size: 17px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #ffffff;
      user-select: none;
    }

    .faq-question:hover {
      background: #f8fafc;
    }

    .faq-answer {
      padding: 0 24px 20px 24px;
      font-size: 15px;
      color: var(--text-muted);
      display: none;
      border-top: 1px dashed var(--border-color);
      padding-top: 16px;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

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

    /* 客户评论 */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

    .review-card {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      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: linear-gradient(135deg, var(--primary) 0%, var(--teal) 100%);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
    }

    /* 文章列表 */
    .news-list {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
      gap: 16px;
    }

    .news-item {
      background: #ffffff;
      padding: 16px 20px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

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

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

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 700;
      font-size: 14px;
    }

    .form-group input, .form-group select, .form-group textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 15px;
      outline: none;
      transition: border 0.2s;
    }

    .form-group input:focus, .form-group select:focus, .form-group textarea:focus {
      border-color: var(--primary);
    }

    .qr-box {
      text-align: center;
      background: #f8fafc;
      padding: 24px;
      border-radius: 12px;
      border: 1px solid var(--border-color);
    }

    .qr-box img {
      max-width: 160px;
      border-radius: 8px;
      margin-bottom: 12px;
    }

    /* 页脚与底栏 */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px 0;
      border-top: 4px solid var(--primary);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: #ffffff;
      margin-bottom: 20px;
      font-size: 16px;
    }

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

    .footer-links li {
      margin-bottom: 10px;
    }

    .footer-links a {
      color: #94a3b8;
    }

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

    .friendship-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      padding-top: 20px;
      border-top: 1px solid #334155;
    }

    .friendship-links a {
      color: #cbd5e1;
      font-size: 13px;
    }

    .copyright {
      text-align: center;
      margin-top: 30px;
      font-size: 13px;
      color: #64748b;
    }

    /* 浮动客服 */
    .float-kefu {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .float-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      box-shadow: 0 4px 12px rgba(0,0,0,0.2);
      cursor: pointer;
    }

    /* 响应式调整 */
    @media (max-width: 1024px) {
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .process-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        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;
        box-shadow: var(--shadow-md);
        border-bottom: 2px solid var(--border-color);
      }

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

      .menu-toggle {
        display: block;
      }

      .hero-title {
        font-size: 28px;
      }

      .hero-metrics {
        grid-template-columns: 1fr;
      }

      .process-steps {
        grid-template-columns: 1fr;
      }

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