:root {
      --primary: #2563eb;
      --primary-dark: #1d4ed8;
      --accent: #ff5722;
      --accent-hover: #f4511e;
      --highlight: #06b6d4;
      --text-main: #0f172a;
      --text-muted: #475569;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.05);
      --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08);
      --shadow-lg: 0 20px 30px -10px rgba(37, 99, 235, 0.15);
      --radius: 12px;
    }
    * {
      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-main);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      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: 76px;
    }
    .brand-wrap {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .brand-wrap .ai-page-logo {
      height: 42px;
      width: auto;
      display: block;
    }
    .brand-text {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      gap: 0;
      list-style: none;
      align-items: center;
    }
    .nav-links li a {
      padding: 8px 14px;
      font-size: 0.938rem;
      font-weight: 600;
      color: var(--text-muted);
      transition: color 0.2s ease, background-color 0.2s ease;
      border-radius: 6px;
      display: inline-block;
    }
    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--primary);
      background-color: #eff6ff;
    }
    .header-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: 8px;
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
      white-space: nowrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
    }
    .btn-accent {
      background: linear-gradient(135deg, var(--accent) 0%, #ea580c 100%);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(255, 87, 34, 0.25);
    }
    .btn-accent:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(255, 87, 34, 0.35);
    }
    .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
      background: #ffffff;
    }
    .btn-outline:hover {
      background: #eff6ff;
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
    }
    .section-spacing {
      padding-top: 80px;
      padding-bottom: 80px;
    }
    .section-header {
      text-align: center;
      max-width: 800px;
      margin: 0 auto 50px auto;
    }
    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      font-size: 0.813rem;
      font-weight: 700;
      color: #ea580c;
      background: #fff7ed;
      border: 1px solid #ffedd5;
      border-radius: 9999px;
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 2.15rem;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 14px;
    }
    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 首屏 Hero 无图片纯CSS撞色构图 */
    .hero-section {
      position: relative;
      overflow: hidden;
      background: radial-gradient(circle at 10% 20%, rgba(37, 99, 235, 0.08) 0%, transparent 40%),
                  radial-gradient(circle at 90% 80%, rgba(255, 87, 34, 0.08) 0%, transparent 45%),
                  #ffffff;
      padding: 90px 0 80px 0;
      border-bottom: 1px solid var(--border-color);
    }
    .hero-content {
      text-align: center;
      max-width: 960px;
      margin: 0 auto;
    }
    .hero-tag {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      border-radius: 9999px;
      background: #eff6ff;
      border: 1px solid #bfdbfe;
      color: var(--primary);
      font-size: 0.875rem;
      font-weight: 700;
      margin-bottom: 24px;
    }
    .hero-tag span {
      display: inline-block;
      width: 8px;
      height: 8px;
      background: var(--accent);
      border-radius: 50%;
    }
    .hero-title {
      font-size: 3rem;
      font-weight: 900;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 24px;
      letter-spacing: -0.5px;
    }
    .hero-title .highlight-text {
      color: var(--primary);
      position: relative;
    }
    .hero-title .accent-text {
      color: var(--accent);
    }
    .hero-subtitle {
      font-size: 1.2rem;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
      max-width: 820px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-btn-group {
      display: flex;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 50px;
    }
    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-md);
      border: 1px solid var(--border-color);
    }
    .stat-card {
      text-align: center;
      padding: 12px;
      border-right: 1px solid var(--border-color);
    }
    .stat-card:last-child {
      border-right: none;
    }
    .stat-num {
      font-size: 2.2rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }
    .stat-num span {
      color: var(--accent);
      font-size: 1.4rem;
    }
    .stat-label {
      font-size: 0.875rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* 平台矩阵与模型展示 */
    .model-badge-container {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 24px;
    }
    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: 8px;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      transition: all 0.2s ease;
    }
    .model-chip:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-2px);
    }

    /* 网格卡片通则 */
    .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: 32px;
    }

    /* 服务卡片 */
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      position: relative;
    }
    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: rgba(37, 99, 235, 0.4);
    }
    .feature-icon-box {
      width: 54px;
      height: 54px;
      border-radius: 10px;
      background: #eff6ff;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.3rem;
      margin-bottom: 20px;
    }
    .feature-icon-box.orange {
      background: #fff7ed;
      color: var(--accent);
    }
    .feature-title {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    .feature-desc {
      font-size: 0.938rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 流程时间线 */
    .step-list {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 16px;
      position: relative;
    }
    .step-item {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      text-align: center;
      position: relative;
    }
    .step-idx {
      width: 36px;
      height: 36px;
      background: var(--accent);
      color: #ffffff;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin-bottom: 14px;
    }
    .step-name {
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .step-sub {
      font-size: 0.85rem;
      color: var(--text-muted);
    }

    /* 评测板块明艳卡片 */
    .review-score-panel {
      background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 50%, #2563eb 100%);
      color: #ffffff;
      border-radius: 16px;
      padding: 40px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 30px;
      margin-bottom: 40px;
      box-shadow: var(--shadow-lg);
    }
    .score-badge {
      display: flex;
      align-items: center;
      gap: 20px;
    }
    .score-number {
      font-size: 4rem;
      font-weight: 900;
      line-height: 1;
      color: #facc15;
    }
    .score-meta h3 {
      font-size: 1.5rem;
      margin-bottom: 6px;
    }
    .score-stars {
      color: #facc15;
      font-size: 1.25rem;
      letter-spacing: 2px;
    }

    /* 表格组件 */
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .comp-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
    }
    .comp-table th,
    .comp-table td {
      padding: 18px 24px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }
    .comp-table th {
      background: #f8fafc;
      font-weight: 700;
      color: var(--text-main);
    }
    .comp-table tr:last-child td {
      border-bottom: none;
    }
    .comp-table .cell-highlight {
      background: #eff6ff;
      font-weight: 700;
      color: var(--primary);
    }
    .tag-green {
      color: #16a34a;
      background: #dcfce7;
      padding: 4px 10px;
      border-radius: 4px;
      font-weight: 600;
      font-size: 0.825rem;
    }

    /* 案例图片展示容器 */
    .case-card {
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #f1f5f9;
      overflow: hidden;
    }
    .case-img-wrap.square {
      aspect-ratio: 1 / 1;
    }
    .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(1.04);
    }
    .case-body {
      padding: 20px;
    }
    .case-title {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .case-desc {
      font-size: 0.875rem;
      color: var(--text-muted);
    }

    /* 宣传图画廊 */
    .promo-gallery {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 30px;
    }
    .promo-gallery-item {
      border-radius: 8px;
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      aspect-ratio: 4 / 3;
    }
    .promo-gallery-item img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    /* 用户评论 */
    .review-card {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
    }
    .avatar-circle {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: #dbeafe;
      color: var(--primary);
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.1rem;
    }
    .user-info h4 {
      font-size: 0.95rem;
      font-weight: 700;
    }
    .user-info span {
      font-size: 0.813rem;
      color: var(--text-muted);
    }
    .review-text {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 表单区域 */
    .form-wrapper {
      background: #ffffff;
      border-radius: 16px;
      border: 1px solid var(--border-color);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }
    .form-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
    }
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .form-group.full-width {
      grid-column: span 2;
    }
    .form-group label {
      font-size: 0.9rem;
      font-weight: 700;
      color: var(--text-main);
    }
    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.95rem;
      outline: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
      background: #ffffff;
      font-family: inherit;
    }
    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }
    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    /* FAQ 手风琴 */
    .faq-container {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 10px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-icon {
      font-size: 1.25rem;
      font-weight: 300;
      transition: transform 0.3s ease;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
      color: var(--accent);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      color: var(--text-muted);
      font-size: 0.938rem;
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      padding-bottom: 20px;
      max-height: 300px;
    }

    /* 文章列表 */
    .article-row {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .article-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #ffffff;
      padding: 18px 24px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      transition: all 0.2s ease;
    }
    .article-item:hover {
      border-color: var(--primary);
      transform: translateX(4px);
    }
    .article-name {
      font-weight: 600;
      color: var(--text-main);
    }
    .article-link-tag {
      font-size: 0.875rem;
      color: var(--primary);
      font-weight: 700;
    }

    /* 页脚统一规范 */
    footer {
      background: #0f172a;
      color: #94a3b8;
      padding-top: 60px;
      padding-bottom: 30px;
      border-top: 1px solid #1e293b;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 50px;
    }
    .footer-col h4 {
      color: #ffffff;
      font-size: 1.1rem;
      margin-bottom: 20px;
      font-weight: 700;
    }
    .footer-col p {
      font-size: 0.9rem;
      line-height: 1.7;
      margin-bottom: 12px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links li a {
      color: #94a3b8;
      font-size: 0.9rem;
      transition: color 0.2s ease;
    }
    .footer-links li a:hover {
      color: #ffffff;
    }
    .qr-box {
      display: flex;
      align-items: center;
      gap: 16px;
      background: #1e293b;
      padding: 16px;
      border-radius: 8px;
    }
    .qr-box img {
      width: 74px;
      height: 74px;
      border-radius: 4px;
      background: #ffffff;
      padding: 2px;
    }
    .qr-info {
      font-size: 0.85rem;
      color: #cbd5e1;
    }
    .friend-links-wrap {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      margin-bottom: 24px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 14px;
      font-size: 0.85rem;
    }
    .friend-links-wrap a {
      color: #64748b;
      transition: color 0.2s ease;
    }
    .friend-links-wrap a:hover {
      color: var(--primary);
    }
    .copyright-bar {
      border-top: 1px solid #1e293b;
      padding-top: 20px;
      text-align: center;
      font-size: 0.825rem;
      color: #64748b;
    }

    /* 悬浮工具栏 */
    .floating-bar {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 48px;
      height: 48px;
      background: #ffffff;
      color: var(--primary);
      box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1rem;
      border: 1px solid var(--border-color);
      cursor: pointer;
      transition: all 0.25s ease;
    }
    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      transform: translateY(-3px);
    }
    .float-btn.accent {
      background: var(--accent);
      color: #ffffff;
      border: none;
    }
    .float-btn.accent:hover {
      background: var(--accent-hover);
    }

    /* 移动端响应式适配 */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .grid-4, .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .step-list {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-stats {
        grid-template-columns: repeat(2, 1fr);
      }
      .stat-card:nth-child(2) {
        border-right: none;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .promo-gallery {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .menu-toggle {
        display: block;
      }
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 76px;
        left: 0;
        width: 100%;
        background: #ffffff;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.show {
        display: flex;
      }
      .hero-title {
        font-size: 1.85rem;
      }
      .grid-4, .grid-3, .grid-2 {
        grid-template-columns: 1fr;
      }
      .step-list {
        grid-template-columns: 1fr;
      }
      .hero-stats {
        grid-template-columns: 1fr;
      }
      .stat-card {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
      }
      .stat-card:last-child {
        border-bottom: none;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .form-group.full-width {
        grid-column: span 1;
      }
      .review-score-panel {
        flex-direction: column;
        text-align: center;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .promo-gallery {
        grid-template-columns: 1fr;
      }
    }