/* 全局变量与活力亮彩渐变风格 */
    :root {
      --primary: #6366f1;
      --primary-dark: #4f46e5;
      --secondary: #ec4899;
      --accent: #06b6d4;
      --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #e0e7ff 50%, #fae8ff 100%);
      --card-bg: rgba(255, 255, 255, 0.95);
      --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, 0.1);
      --shadow-lg: 0 20px 30px -10px rgba(79, 70, 229, 0.15);
      --radius: 12px;
      --container-max: 1200px;
    }

    * {
      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: #f8fafc;
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      background: var(--bg-gradient);
      background-attachment: fixed;
      min-height: 100vh;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 1.5rem;
      width: 100%;
    }

    /* 顶部导航 */
    header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    .nav-brand {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
      color: var(--text-main);
      font-weight: 700;
      font-size: 1.25rem;
    }

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

    .nav-links {
      display: flex;
      gap: 0; /* 严格符合规则 */
      list-style: none;
      align-items: center;
    }

    .nav-links li a {
      text-decoration: none;
      color: var(--text-main);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0.8rem;
      border-radius: 6px;
      transition: all 0.25s ease;
      display: inline-block;
    }

    .nav-links li 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: 0.6rem 1.4rem;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: 50px;
      text-decoration: none;
      cursor: pointer;
      transition: all 0.3s ease;
      border: none;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: #ffffff;
      box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(99, 102, 241, 0.45);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }

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

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

    /* Hero 首屏 - 严格禁止出现任何图片 */
    .hero-section {
      padding: 5rem 0 4rem;
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-badge {
      display: inline-block;
      padding: 0.4rem 1.2rem;
      background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(236, 72, 153, 0.15));
      border: 1px solid rgba(99, 102, 241, 0.3);
      border-radius: 50px;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--primary-dark);
      margin-bottom: 1.5rem;
    }

    .hero-title {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 1.25rem;
      letter-spacing: -0.5px;
    }

    .hero-subtitle {
      font-size: 1.15rem;
      color: var(--text-muted);
      max-width: 800px;
      margin: 0 auto 2.5rem;
    }

    .hero-cta-group {
      display: flex;
      justify-content: center;
      gap: 1rem;
      margin-bottom: 3.5rem;
      flex-wrap: wrap;
    }

    .btn-hero-main {
      padding: 0.9rem 2.2rem;
      font-size: 1.1rem;
    }

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      margin-top: 2rem;
    }

    .stat-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      padding: 1.5rem;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: transform 0.3s ease;
    }

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

    .stat-number {
      font-size: 2rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      margin-bottom: 0.25rem;
    }

    .stat-label {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 版块通用基础 */
    section {
      padding: 4.5rem 0;
    }

    .section-header {
      text-align: center;
      margin-bottom: 3rem;
    }

    .section-tag {
      font-size: 0.85rem;
      font-weight: 700;
      text-transform: uppercase;
      color: var(--primary);
      letter-spacing: 1px;
      margin-bottom: 0.5rem;
      display: block;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 0.75rem;
    }

    .section-desc {
      color: var(--text-muted);
      font-size: 1rem;
      max-width: 650px;
      margin: 0 auto;
    }

    /* 网格与卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
    }

    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }

    .feature-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 1.75rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }

    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: rgba(99, 102, 241, 0.4);
    }

    .feature-icon {
      width: 48px;
      height: 48px;
      border-radius: 10px;
      background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(236, 72, 153, 0.1));
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 1.25rem;
      font-weight: bold;
    }

    .feature-card h3 {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 0.75rem;
      color: var(--text-main);
    }

    .feature-card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      flex-grow: 1;
    }

    /* 对比评测表格 */
    .eval-box {
      background: var(--card-bg);
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      padding: 2rem;
      box-shadow: var(--shadow-md);
    }

    .score-banner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: linear-gradient(135deg, #EEF2FF 0%, #FCE7F3 100%);
      padding: 1.5rem;
      border-radius: 10px;
      margin-bottom: 2rem;
    }

    .score-info h4 {
      font-size: 1.3rem;
      color: var(--text-main);
      margin-bottom: 0.25rem;
    }

    .rating-stars {
      color: #f59e0b;
      font-size: 1.2rem;
    }

    .score-badge {
      text-align: right;
    }

    .score-num {
      font-size: 2.5rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }

    .eval-table-wrapper {
      overflow-x: auto;
    }

    .eval-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.95rem;
    }

    .eval-table th, .eval-table td {
      padding: 1rem 1.25rem;
      border-bottom: 1px solid var(--border-color);
    }

    .eval-table th {
      background: #f1f5f9;
      color: var(--text-main);
      font-weight: 700;
    }

    .eval-table tr:hover {
      background: rgba(99, 102, 241, 0.02);
    }

    .highlight-col {
      background: rgba(99, 102, 241, 0.05);
      font-weight: 600;
      color: var(--primary-dark);
    }

    /* 流程步骤 */
    .process-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      position: relative;
    }

    .step-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 1.5rem;
      text-align: center;
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 1rem;
    }

    /* 案例中心 */
    .case-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s ease;
    }

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

    .case-img-wrap {
      width: 100%;
      height: 200px;
      overflow: hidden;
      background: #e2e8f0;
    }

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

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

    .case-body {
      padding: 1.25rem;
    }

    .case-body h4 {
      font-size: 1.1rem;
      margin-bottom: 0.5rem;
      color: var(--text-main);
    }

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

    /* 折叠 FAQ */
    .faq-list {
      max-width: 850px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }

    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      transition: all 0.3s ease;
    }

    .faq-question {
      padding: 1.25rem 1.5rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-main);
      user-select: none;
    }

    .faq-question::after {
      content: "+";
      font-size: 1.4rem;
      color: var(--primary);
      transition: transform 0.3s ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: rgba(248, 250, 252, 0.8);
      color: var(--text-muted);
      font-size: 0.95rem;
      padding: 0 1.5rem;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 1rem 1.5rem 1.5rem;
      border-top: 1px solid var(--border-color);
    }

    /* 评论卡片 */
    .review-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 1.5rem;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-text {
      font-style: italic;
      color: var(--text-muted);
      font-size: 0.95rem;
      margin-bottom: 1.25rem;
    }

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

    .user-avatar {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }

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

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

    /* 表单与联系 */
    .contact-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem;
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 2.5rem;
      box-shadow: var(--shadow-lg);
    }

    .contact-info h3 {
      font-size: 1.5rem;
      margin-bottom: 1rem;
    }

    .contact-item {
      margin-bottom: 1.25rem;
      display: flex;
      align-items: flex-start;
      gap: 12px;
    }

    .contact-item strong {
      color: var(--text-main);
      min-width: 80px;
    }

    .qr-box {
      margin-top: 1.5rem;
      text-align: center;
      display: inline-block;
      padding: 1rem;
      background: #f8fafc;
      border: 1px solid var(--border-color);
      border-radius: 8px;
    }

    .qr-box img {
      width: 140px;
      height: 140px;
      object-fit: cover;
      border-radius: 6px;
    }

    .form-group {
      margin-bottom: 1.25rem;
    }

    .form-group label {
      display: block;
      margin-bottom: 0.4rem;
      font-weight: 600;
      font-size: 0.9rem;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 0.75rem 1rem;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.95rem;
      background: #ffffff;
      color: var(--text-main);
      transition: border-color 0.25s ease;
    }

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

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

    /* 标签云 */
    .tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 0.6rem;
      margin-top: 1rem;
    }

    .tag-item {
      background: #eef2ff;
      color: var(--primary-dark);
      padding: 0.35rem 0.85rem;
      border-radius: 50px;
      font-size: 0.85rem;
      font-weight: 500;
      border: 1px solid rgba(99, 102, 241, 0.2);
    }

    /* 文章列表 */
    .article-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.8rem;
    }

    .article-item {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: 8px;
      padding: 1rem 1.25rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: transform 0.2s ease;
    }

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

    .article-item a {
      color: var(--text-main);
      text-decoration: none;
      font-weight: 500;
    }

    .article-item a:hover {
      color: var(--primary);
    }

    /* 页脚与友情链接 */
    footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 4rem 0 2rem;
      margin-top: 4rem;
      border-top: 1px solid #1e293b;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 2rem;
      margin-bottom: 3rem;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1.1rem;
      margin-bottom: 1.25rem;
    }

    .footer-col p {
      font-size: 0.9rem;
      line-height: 1.7;
    }

    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.6rem;
    }

    .footer-links a {
      color: #94a3b8;
      text-decoration: none;
      font-size: 0.9rem;
      transition: color 0.25s ease;
    }

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

    .friend-links-box {
      border-top: 1px solid #1e293b;
      padding-top: 1.5rem;
      margin-bottom: 1.5rem;
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      align-items: center;
    }

    .friend-links-box span {
      color: #ffffff;
      font-weight: 600;
      font-size: 0.9rem;
    }

    .friend-links-box a {
      color: #94a3b8;
      text-decoration: none;
      font-size: 0.88rem;
      transition: color 0.2s ease;
    }

    .friend-links-box a:hover {
      color: var(--secondary);
    }

    .copyright {
      text-align: center;
      border-top: 1px solid #1e293b;
      padding-top: 1.5rem;
      font-size: 0.85rem;
      color: #64748b;
    }

    /* 浮动客服 */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 80px;
      z-index: 999;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #ffffff;
      padding: 12px 18px;
      border-radius: 50px;
      box-shadow: 0 10px 20px rgba(0,0,0,0.2);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      font-weight: 600;
      font-size: 0.9rem;
      transition: transform 0.3s ease;
    }

    .floating-kefu:hover {
      transform: scale(1.05);
    }

    .back-to-top {
      position: fixed;
      right: 20px;
      bottom: 25px;
      z-index: 999;
      width: 40px;
      height: 40px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      box-shadow: var(--shadow-sm);
      color: var(--text-main);
      font-weight: bold;
      transition: all 0.3s ease;
    }

    .back-to-top:hover {
      background: var(--primary);
      color: #ffffff;
    }

    /* 移动端响应式 */
    @media (max-width: 992px) {
      .hero-stats { grid-template-columns: repeat(2, 1fr); }
      .grid-3, .grid-4, .process-steps { grid-template-columns: repeat(2, 1fr); }
      .contact-container { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .hero-title { font-size: 2rem; }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active { display: flex; }
      .nav-toggle { display: block; }
      .grid-2, .grid-3, .grid-4, .hero-stats, .process-steps { grid-template-columns: 1fr; }
      .score-banner { flex-direction: column; text-align: center; gap: 1rem; }
      .score-badge { text-align: center; }
      .footer-grid { grid-template-columns: 1fr; }
    }