:root {
      --primary: #f95700;
      --primary-hover: #e04a00;
      --primary-light: #fff3ec;
      --primary-border: #ffd1b8;
      --accent: #ff7a00;
      --text-main: #1f2429;
      --text-regular: #4b5563;
      --text-muted: #6b7280;
      --bg-main: #fbfbfd;
      --bg-card: #ffffff;
      --border-color: #ebeef2;
      --shadow-sm: 0 2px 8px rgba(249, 87, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(249, 87, 0, 0.08);
      --shadow-lg: 0 16px 36px rgba(249, 87, 0, 0.12);
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --container-width: 1200px;
    }

    * {
      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, sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.65;
      overflow-x: hidden;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

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

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

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

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: 0 2px 10px rgba(0,0,0,0.03);
    }

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

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

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

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

    .nav-links li a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 10px 14px;
      display: block;
      transition: color 0.2s, background 0.2s;
      border-radius: var(--radius-sm);
    }

    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--primary);
      background-color: var(--primary-light);
    }

    .header-actions {
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--accent) 0%, var(--primary) 100%);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(249, 87, 0, 0.3);
    }

    .btn-primary:hover {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-hover) 100%);
      box-shadow: 0 6px 18px rgba(249, 87, 0, 0.4);
      transform: translateY(-2px);
    }

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

    .btn-outline:hover {
      background-color: var(--primary-light);
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    .mobile-menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }

    .mobile-menu-toggle span {
      width: 24px;
      height: 2px;
      background: var(--text-main);
      transition: 0.3s;
    }

    /* 主体内容与模块间距 */
    main {
      flex: 1;
      width: 100%;
    }

    section {
      padding: 80px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      margin-bottom: 50px;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }

    .section-badge {
      display: inline-block;
      font-size: 13px;
      font-weight: 600;
      color: var(--primary);
      background: var(--primary-light);
      border: 1px solid var(--primary-border);
      padding: 4px 14px;
      border-radius: 20px;
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.35;
      margin-bottom: 14px;
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    /* 首屏 Hero 无图片纯技术质感 */
    .hero-section {
      padding: 90px 0 70px;
      background: radial-gradient(circle at 50% 0%, #fff6ee 0%, #ffffff 70%);
      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;
      background: #ffffff;
      border: 1px solid var(--primary-border);
      color: var(--primary);
      padding: 6px 18px;
      border-radius: 30px;
      font-size: 14px;
      font-weight: 600;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.25;
      color: #111827;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-title .highlight {
      color: var(--primary);
      position: relative;
      display: inline-block;
    }

    .hero-desc {
      font-size: 18px;
      color: var(--text-regular);
      line-height: 1.7;
      margin-bottom: 36px;
    }

    .hero-cta {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 18px;
      margin-bottom: 50px;
      flex-wrap: wrap;
    }

    .hero-cta .btn-primary {
      padding: 14px 34px;
      font-size: 17px;
    }

    .hero-cta .btn-outline {
      padding: 14px 30px;
      font-size: 16px;
    }

    /* 首屏数据指标卡片 */
    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
    }

    .metric-item {
      text-align: center;
      border-right: 1px solid var(--border-color);
      padding: 10px 16px;
    }

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

    .metric-number {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }

    .metric-label {
      font-size: 14px;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 平台支持模型标签滚动条 */
    .model-pills-bar {
      margin-top: 36px;
      padding-top: 24px;
      border-top: 1px dashed var(--border-color);
      display: flex;
      align-items: center;
      gap: 12px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .model-pill-badge {
      font-size: 13px;
      background: #f3f4f6;
      color: #374151;
      padding: 5px 12px;
      border-radius: 16px;
      font-weight: 500;
    }

    /* 通用卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 26px;
    }

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

    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
      position: relative;
    }

    .card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-border);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 20px;
    }

    .card-title {
      font-size: 19px;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-main);
    }

    .card-text {
      font-size: 14px;
      color: var(--text-regular);
      line-height: 1.6;
    }

    /* 平台核心架构优势 (关于我们) */
    .about-box {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 40px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .about-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 24px;
    }

    .about-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      font-size: 15px;
      color: var(--text-regular);
    }

    .about-list li strong {
      color: var(--text-main);
    }

    .about-dot {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      margin-top: 8px;
      flex-shrink: 0;
    }

    .img-wrapper {
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      background: #f9fafb;
    }

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

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

    .step-num {
      font-size: 13px;
      font-weight: 700;
      color: var(--primary);
      background: var(--primary-light);
      padding: 2px 10px;
      border-radius: 12px;
      display: inline-block;
      margin-bottom: 14px;
    }

    /* 对比评测卡片与表格 */
    .evaluation-card {
      background: #ffffff;
      border: 1px solid var(--primary-border);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-md);
      margin-bottom: 40px;
    }

    .score-summary {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
      padding-bottom: 24px;
      border-bottom: 1px solid var(--border-color);
      margin-bottom: 28px;
    }

    .score-rate {
      display: flex;
      align-items: baseline;
      gap: 12px;
    }

    .big-score {
      font-size: 54px;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }

    .full-score {
      font-size: 18px;
      color: var(--text-muted);
    }

    .stars-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 15px;
      font-weight: 700;
      background: #fff8e8;
      color: #b45309;
      border: 1px solid #fde68a;
      padding: 6px 14px;
      border-radius: 20px;
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
    }

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

    .compare-table th,
    .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 15px;
    }

    .compare-table th {
      background: #fdfaf8;
      font-weight: 700;
      color: var(--text-main);
    }

    .compare-table td.highlight-cell {
      background: var(--primary-light);
      color: var(--primary);
      font-weight: 700;
    }

    /* 案例中心 */
    .case-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }

    .case-card-body {
      padding: 22px;
      flex: 1;
    }

    .case-tag {
      font-size: 12px;
      font-weight: 600;
      color: var(--primary);
      background: var(--primary-light);
      padding: 2px 8px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 10px;
    }

    /* 用户评论 */
    .testimonial-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 26px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-quote {
      font-size: 15px;
      color: var(--text-regular);
      line-height: 1.65;
      margin-bottom: 20px;
      font-style: normal;
    }

    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f3f4f6;
      padding-top: 16px;
    }

    .user-avatar-text {
      width: 42px;
      height: 42px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 15px;
    }

    .user-name {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
    }

    .user-title {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* FAQ 手风琴 */
    .faq-wrapper {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

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

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

    .faq-header {
      padding: 18px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      user-select: none;
      font-weight: 600;
      font-size: 16px;
      color: var(--text-main);
      background: #ffffff;
    }

    .faq-header:hover {
      background: #fffbf9;
      color: var(--primary);
    }

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

    .faq-accordion-item.active .faq-toggle-icon {
      transform: rotate(45deg);
      color: var(--primary);
    }

    .faq-body {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #ffffff;
    }

    .faq-body-inner {
      padding: 0 24px 20px;
      font-size: 14.5px;
      color: var(--text-regular);
      line-height: 1.65;
    }

    /* 需求匹配与表单 */
    .match-section {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }

    .form-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 40px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .custom-form {
      display: flex;
      flex-direction: column;
      gap: 18px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .form-group label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 14.5px;
      color: var(--text-main);
      outline: none;
      transition: border-color 0.2s, box-shadow 0.2s;
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(249, 87, 0, 0.12);
    }

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

    .kefu-card {
      background: #fafafb;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      justify-content: center;
    }

    .kefu-qrcode-wrap {
      width: 150px;
      height: 150px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-color);
      padding: 8px;
      background: #ffffff;
      margin-bottom: 14px;
    }

    /* 资讯与友情链接 */
    .article-links-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      margin-top: 20px;
    }

    .article-link-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 14px;
    }

    .article-link-item {
      display: inline-block;
      font-size: 14px;
      color: var(--primary);
      background: var(--primary-light);
      padding: 6px 14px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--primary-border);
    }

    .article-link-item:hover {
      background: var(--primary);
      color: #ffffff;
    }

    /* 页脚 */
    .site-footer {
      background: #191c20;
      color: #e5e7eb;
      padding: 60px 0 30px;
      border-top: 1px solid #282c34;
      margin-top: auto;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      padding-bottom: 40px;
      border-bottom: 1px solid #2e343e;
    }

    .footer-col h4 {
      font-size: 16px;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 20px;
      position: relative;
    }

    .footer-col h4::after {
      content: "";
      position: absolute;
      left: 0;
      bottom: -6px;
      width: 24px;
      height: 2px;
      background: var(--primary);
    }

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

    .footer-links a {
      color: #9ca3af;
      font-size: 14px;
    }

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

    .footer-friend-links {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    .footer-friend-links a {
      color: #9ca3af;
      font-size: 13px;
      background: #252a32;
      padding: 4px 10px;
      border-radius: 4px;
    }

    .footer-friend-links a:hover {
      color: #ffffff;
      background: var(--primary);
    }

    .footer-bottom {
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: #6b7280;
      display: flex;
      flex-direction: column;
      gap: 8px;
      align-items: center;
    }

    .footer-bottom a {
      color: #9ca3af;
    }

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

    /* 浮动组件 */
    .float-toolbar {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #ffffff;
      color: var(--primary);
      border: 1px solid var(--border-color);
      box-shadow: 0 4px 14px rgba(0,0,0,0.12);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 13px;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      transform: scale(1.06);
    }

    /* 响应式调整 */
    @media (max-width: 1024px) {
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
      }
      .metric-item:nth-child(2) {
        border-right: none;
      }
      .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;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-links.show {
        display: flex;
      }
      .mobile-menu-toggle {
        display: flex;
      }
      .hero-title {
        font-size: 28px;
      }
      .hero-desc {
        font-size: 15px;
      }
      .about-box,
      .form-wrapper {
        grid-template-columns: 1fr;
        padding: 24px;
      }
      .grid-3,
      .grid-4,
      .flow-steps {
        grid-template-columns: 1fr;
      }
      .hero-metrics {
        grid-template-columns: 1fr;
      }
      .metric-item {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding-bottom: 14px;
      }
      .metric-item:last-child {
        border-bottom: none;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }