:root {
      --primary: #0284c7;
      --primary-gradient: linear-gradient(135deg, #0ea5e9 0%, #6366f1 50%, #ec4899 100%);
      --neon-cyan: #06b6d4;
      --neon-pink: #ec4899;
      --neon-purple: #8b5cf6;
      --bg-slate: #f8fafc;
      --card-bg: rgba(255, 255, 255, 0.92);
      --text-main: #0f172a;
      --text-muted: #475569;
      --border-color: rgba(226, 232, 240, 0.8);
      --border-neon: rgba(14, 165, 233, 0.3);
      --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 20px 25px -5px rgba(14, 165, 233, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
      --radius: 14px;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-slate);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
      background-image: 
        radial-gradient(circle at 10% 20%, rgba(14, 165, 233, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(236, 72, 153, 0.05) 0%, transparent 40%);
    }

    /* 统一居中容器 */
    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航 */
    header.site-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: 0 2px 10px rgba(0,0,0,0.03);
    }

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

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

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

    .brand-name {
      font-size: 1.25rem;
      font-weight: 800;
      background: var(--primary-gradient);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    nav.main-nav {
      display: flex;
      align-items: center;
    }

    /* 规则要求: .nav-links 的 gap 属性必须设置为 0 */
    .nav-links {
      display: flex;
      gap: 0;
      list-style: none;
      align-items: center;
    }

    .nav-links li a {
      display: inline-block;
      padding: 8px 14px;
      color: var(--text-main);
      text-decoration: none;
      font-size: 0.92rem;
      font-weight: 500;
      transition: all 0.2s ease;
      border-radius: 6px;
    }

    .nav-links li a:hover {
      color: var(--primary);
      background: rgba(14, 165, 233, 0.08);
    }

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

    .btn-neon-sm {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 8px 18px;
      border-radius: 50px;
      font-size: 0.88rem;
      font-weight: 600;
      text-decoration: none;
      color: #fff;
      background: linear-gradient(135deg, #0ea5e9 0%, #8b5cf6 100%);
      box-shadow: 0 4px 12px rgba(14, 165, 233, 0.3);
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .btn-neon-sm:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(14, 165, 233, 0.45);
    }

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

    /* 通用 Section 风格 */
    section.page-section {
      padding: 80px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      max-width: 800px;
      margin: 0 auto 50px;
    }

    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      border-radius: 20px;
      background: rgba(14, 165, 233, 0.1);
      color: var(--primary);
      font-size: 0.82rem;
      font-weight: 700;
      letter-spacing: 1px;
      text-transform: uppercase;
      margin-bottom: 12px;
      border: 1px solid rgba(14, 165, 233, 0.2);
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }

    .section-subtitle {
      font-size: 1.05rem;
      color: var(--text-muted);
    }

    /* 首屏 HERO 区域 - 严禁出现图片 */
    .hero-section {
      padding: 90px 0 70px;
      text-align: center;
      background: radial-gradient(circle at 50% 30%, rgba(14, 165, 233, 0.12) 0%, rgba(248, 250, 252, 0) 70%);
    }

    .hero-title-h1 {
      font-size: 2.6rem;
      font-weight: 900;
      line-height: 1.25;
      margin-bottom: 20px;
      color: var(--text-main);
    }

    .hero-title-h1 span {
      background: var(--primary-gradient);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-desc {
      font-size: 1.2rem;
      color: var(--text-muted);
      max-width: 850px;
      margin: 0 auto 32px;
      line-height: 1.7;
    }

    .hero-tags {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
      margin-bottom: 36px;
    }

    .hero-tag-item {
      background: rgba(255, 255, 255, 0.9);
      border: 1px solid var(--border-neon);
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 0.88rem;
      color: var(--text-main);
      font-weight: 600;
      box-shadow: 0 2px 8px rgba(0,0,0,0.03);
    }

    .hero-buttons {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 50px;
    }

    .btn-main-hero {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 14px 36px;
      font-size: 1.1rem;
      font-weight: 700;
      color: #fff;
      text-decoration: none;
      background: linear-gradient(135deg, #0ea5e9 0%, #6366f1 50%, #ec4899 100%);
      border-radius: 50px;
      box-shadow: 0 10px 25px rgba(14, 165, 233, 0.35);
      transition: all 0.3s ease;
    }

    .btn-main-hero:hover {
      transform: translateY(-3px);
      box-shadow: 0 15px 30px rgba(14, 165, 233, 0.5);
    }

    .btn-secondary-hero {
      display: inline-flex;
      align-items: center;
      padding: 14px 32px;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-main);
      text-decoration: none;
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: 50px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }

    .btn-secondary-hero:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-2px);
    }

    /* 指标卡片 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 20px;
    }

    .metric-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      padding: 24px 16px;
      border-radius: var(--radius);
      text-align: center;
      box-shadow: var(--shadow-sm);
      position: relative;
      overflow: hidden;
    }

    .metric-card::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--primary-gradient);
    }

    .metric-num {
      font-size: 2.2rem;
      font-weight: 900;
      color: var(--primary);
      margin-bottom: 4px;
    }

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

    /* 卡片网格 */
    .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: 30px;
    }

    .feature-card {
      background: var(--card-bg);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 28px 24px;
      transition: all 0.3s ease;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: var(--border-neon);
    }

    .card-tag {
      font-size: 0.75rem;
      font-weight: 700;
      color: var(--neon-purple);
      background: rgba(139, 92, 246, 0.1);
      padding: 2px 10px;
      border-radius: 12px;
      display: inline-block;
      margin-bottom: 12px;
      width: fit-content;
    }

    .card-title {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

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

    /* 模型标签云 */
    .models-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      padding: 20px;
      background: #fff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      margin-top: 30px;
    }

    .model-chip {
      background: var(--bg-slate);
      border: 1px solid rgba(14, 165, 233, 0.2);
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--text-main);
    }

    /* 素材图片区域 */
    .media-block {
      margin: 30px 0;
      text-align: center;
      border-radius: var(--radius);
      overflow: hidden;
    }

    .ai-page-image {
      max-width: 100%;
      height: auto;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-color);
    }

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

    .step-card {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      text-align: center;
      position: relative;
    }

    .step-num {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-gradient);
      color: #fff;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-size: 1.1rem;
    }

    /* 对比表格 */
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #fff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

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

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

    .rating-highlight {
      background: rgba(14, 165, 233, 0.05);
      font-weight: 700;
      color: var(--primary);
    }

    .rating-badge {
      display: inline-block;
      background: linear-gradient(135deg, #f59e0b, #ec4899);
      color: #fff;
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 800;
      font-size: 0.9rem;
    }

    /* FAQ 折叠面板 */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

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

    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      font-size: 1.02rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #fff;
      user-select: none;
    }

    .faq-question::after {
      content: "+";
      font-size: 1.4rem;
      color: var(--primary);
      transition: transform 0.2s;
    }

    .faq-item.active .faq-question::after {
      content: "−";
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #f8fafc;
      color: var(--text-muted);
      font-size: 0.94rem;
      line-height: 1.7;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 16px 24px;
      border-top: 1px solid var(--border-color);
    }

    /* 评论卡片 */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

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

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

    .avatar-placeholder {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, #0ea5e9, #ec4899);
      color: #fff;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .author-info h4 {
      font-size: 0.98rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .author-info p {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    .review-stars {
      color: #f59e0b;
      margin-bottom: 8px;
    }

    /* 文章列表 & 外部链接 */
    .article-links-box {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
    }

    .article-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-list li a {
      color: var(--text-main);
      text-decoration: none;
      font-weight: 600;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 8px 12px;
      border-radius: 6px;
      background: var(--bg-slate);
      transition: background 0.2s;
    }

    .article-list li a:hover {
      background: rgba(14, 165, 233, 0.1);
      color: var(--primary);
    }

    /* 表单与联系 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }

    .form-group {
      margin-bottom: 16px;
    }

    .form-group label {
      display: block;
      font-size: 0.88rem;
      font-weight: 700;
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.92rem;
      background: var(--bg-slate);
      color: var(--text-main);
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #fff;
    }

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

    .btn-submit {
      width: 100%;
      padding: 12px;
      border: none;
      border-radius: 8px;
      background: var(--primary-gradient);
      color: #fff;
      font-weight: 700;
      font-size: 1rem;
      cursor: pointer;
      transition: opacity 0.2s;
    }

    .btn-submit:hover {
      opacity: 0.92;
    }

    .qr-box {
      text-align: center;
      padding: 20px;
      background: var(--bg-slate);
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
    }

    .qr-box img {
      max-width: 160px;
      height: auto;
      border-radius: 8px;
      margin-bottom: 10px;
    }

    /* 页脚 */
    footer.site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      border-top: 1px solid #1e293b;
      margin-top: 40px;
    }

    .footer-content {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 2fr;
      gap: 30px;
      margin-bottom: 40px;
    }

    .footer-col h3, .footer-col h4 {
      color: #f8fafc;
      margin-bottom: 16px;
      font-size: 1.05rem;
    }

    .footer-col p {
      font-size: 0.88rem;
      line-height: 1.6;
    }

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

    .friend-links a {
      color: #38bdf8;
      text-decoration: none;
      font-size: 0.85rem;
      background: rgba(255,255,255,0.05);
      padding: 4px 10px;
      border-radius: 4px;
    }

    .friend-links a:hover {
      color: #fff;
      background: rgba(56, 189, 248, 0.2);
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      font-size: 0.85rem;
    }

    .ai-page-home-link {
      color: #38bdf8;
      text-decoration: none;
    }

    /* 浮动客服 */
    .float-kefu {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      background: linear-gradient(135deg, #0ea5e9, #ec4899);
      color: #fff;
      padding: 12px 20px;
      border-radius: 30px;
      font-weight: 700;
      box-shadow: 0 10px 20px rgba(0,0,0,0.15);
      text-decoration: none;
      font-size: 0.9rem;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .grid-4, .process-steps { grid-template-columns: repeat(2, 1fr); }
      .grid-3, .reviews-grid { grid-template-columns: repeat(2, 1fr); }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-content { grid-template-columns: 1fr 1fr; }
      .contact-wrapper { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .mobile-menu-toggle { display: block; }
      nav.main-nav {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #fff;
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        box-shadow: 0 10px 15px rgba(0,0,0,0.05);
      }
      nav.main-nav.active { display: block; }
      .nav-links { flex-direction: column; align-items: flex-start; }
      .nav-links li { width: 100%; }
      .nav-links li a { width: 100%; padding: 10px; }
      .hero-title-h1 { font-size: 1.9rem; }
      .grid-3, .grid-2, .reviews-grid, .grid-4, .process-steps, .metrics-grid { grid-template-columns: 1fr; }
      .footer-content { grid-template-columns: 1fr; }
    }