:root {
      --bg-primary: #F8FAFC;
      --bg-surface: #FFFFFF;
      --bg-alt: #F1F5F9;
      --text-main: #0F172A;
      --text-secondary: #334155;
      --text-muted: #64748B;
      --accent-electric: #2563EB;
      --accent-contrast: #FF5500;
      --accent-glow: #FFE500;
      --accent-mint: #059669;
      --border-color: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04);
      --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08);
      --shadow-lg: 0 20px 35px -10px rgba(15, 23, 42, 0.12);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-family);
      background-color: var(--bg-primary);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    /* 全局容器统一规范 */
    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 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 var(--text-main);
      box-shadow: var(--shadow-sm);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
    }

    .logo-box {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
      color: var(--text-main);
      font-weight: 900;
      font-size: 1.25rem;
    }

    .logo-box .ai-page-logo {
      height: 42px;
      width: auto;
    }

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

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

    .nav-links li a {
      display: inline-block;
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 600;
      color: var(--text-main);
      text-decoration: none;
      transition: color 0.2s, background 0.2s;
      border-radius: var(--radius-sm);
    }

    .nav-links li a:hover {
      color: var(--accent-contrast);
      background: rgba(255, 85, 0, 0.08);
    }

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

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

    /* 按钮样式体系 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      padding: 12px 24px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
      cursor: pointer;
      border: 2px solid var(--text-main);
      box-shadow: 3px 3px 0px var(--text-main);
      font-size: 0.95rem;
    }

    .btn:hover {
      transform: translate(-2px, -2px);
      box-shadow: 5px 5px 0px var(--text-main);
    }

    .btn:active {
      transform: translate(1px, 1px);
      box-shadow: 2px 2px 0px var(--text-main);
    }

    .btn-contrast {
      background-color: var(--accent-contrast);
      color: #FFFFFF;
    }

    .btn-electric {
      background-color: var(--accent-electric);
      color: #FFFFFF;
    }

    .btn-glow {
      background-color: var(--accent-glow);
      color: var(--text-main);
    }

    .btn-white {
      background-color: #FFFFFF;
      color: var(--text-main);
    }

    /* 模块通用样式 */
    section {
      padding: 80px 0;
      position: relative;
    }

    .section-title-wrap {
      text-align: center;
      margin-bottom: 50px;
    }

    .section-tag {
      display: inline-block;
      background-color: var(--accent-glow);
      color: var(--text-main);
      font-weight: 800;
      font-size: 0.8rem;
      padding: 4px 14px;
      border-radius: 50px;
      border: 1.5px solid var(--text-main);
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 900;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

    .section-desc {
      color: var(--text-secondary);
      max-width: 680px;
      margin: 12px auto 0;
      font-size: 1.05rem;
    }

    /* 首屏 HERO - 严格纯代码与几何排版 */
    .hero-section {
      padding: 90px 0 80px;
      background: linear-gradient(135deg, #FFFFFF 0%, #EFF6FF 50%, #FFF7ED 100%);
      border-bottom: 2px solid var(--text-main);
      position: relative;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 40px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 2.75rem;
      font-weight: 900;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--text-main);
    }

    .hero-content h1 span {
      background: linear-gradient(90deg, var(--accent-electric), var(--accent-contrast));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      border-bottom: 4px solid var(--accent-glow);
    }

    .hero-intro {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 30px;
      line-height: 1.7;
    }

    .hero-btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      margin-bottom: 35px;
    }

    .hero-stats-row {
      display: flex;
      gap: 24px;
      border-top: 2px dashed var(--border-color);
      padding-top: 24px;
    }

    .hero-stat-item h4 {
      font-size: 1.6rem;
      font-weight: 900;
      color: var(--accent-contrast);
    }

    .hero-stat-item p {
      font-size: 0.85rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* Hero 右侧纯代码构建的视觉面板 */
    .hero-visual-card {
      background: #FFFFFF;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: 8px 8px 0px var(--accent-electric);
    }

    .model-stream-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 16px;
      padding-bottom: 12px;
      border-bottom: 1.5px solid var(--border-color);
    }

    .model-stream-header span {
      font-weight: 800;
      font-size: 0.9rem;
    }

    .model-pill-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      margin-bottom: 20px;
    }

    .model-pill {
      background: var(--bg-alt);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      padding: 8px;
      text-align: center;
      font-size: 0.8rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .model-pill.active {
      background: var(--accent-glow);
      border-color: var(--text-main);
    }

    .workflow-mock {
      background: var(--bg-primary);
      border: 1px dashed var(--text-main);
      border-radius: var(--radius-sm);
      padding: 14px;
      font-size: 0.85rem;
      font-family: monospace;
      color: var(--text-secondary);
      line-height: 1.5;
    }

    /* 卡片网格体系 */
    .cards-grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .cards-grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .cards-grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--bg-surface);
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: 4px 4px 0px var(--text-main);
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: 6px 6px 0px var(--accent-contrast);
    }

    .feature-icon-badge {
      width: 48px;
      height: 48px;
      border-radius: var(--radius-sm);
      border: 2px solid var(--text-main);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.25rem;
      font-weight: 900;
      margin-bottom: 16px;
    }

    .badge-orange { background: var(--accent-contrast); color: #fff; }
    .badge-blue { background: var(--accent-electric); color: #fff; }
    .badge-yellow { background: var(--accent-glow); color: #000; }
    .badge-green { background: var(--accent-mint); color: #fff; }

    .feature-card h3 {
      font-size: 1.15rem;
      font-weight: 800;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .feature-card p {
      font-size: 0.9rem;
      color: var(--text-secondary);
      line-height: 1.6;
    }

    /* 图片与素材容器 */
    .media-card {
      background: var(--bg-surface);
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: 4px 4px 0px var(--text-main);
    }

    .media-wrapper {
      position: relative;
      width: 100%;
      background: var(--bg-alt);
      border-bottom: 2px solid var(--text-main);
    }

    .media-wrapper img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: contain;
    }

    .media-body {
      padding: 20px;
    }

    .media-body h4 {
      font-size: 1.1rem;
      font-weight: 800;
      margin-bottom: 8px;
    }

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

    .step-box {
      background: var(--bg-surface);
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      padding: 24px 20px;
      text-align: center;
      position: relative;
      box-shadow: 4px 4px 0px var(--accent-electric);
    }

    .step-number {
      font-size: 2rem;
      font-weight: 900;
      color: var(--accent-contrast);
      line-height: 1;
      margin-bottom: 12px;
    }

    /* 对比评测表格 */
    .review-highlight {
      background: #FFFBEB;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      padding: 20px;
      margin-bottom: 30px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      box-shadow: 4px 4px 0px var(--accent-glow);
    }

    .review-score-box {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .review-stars {
      color: #F59E0B;
      font-size: 1.4rem;
      letter-spacing: 2px;
    }

    .review-number {
      font-size: 1.8rem;
      font-weight: 900;
      color: var(--accent-contrast);
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      box-shadow: 6px 6px 0px var(--text-main);
      background: #FFFFFF;
    }

    .contrast-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 600px;
    }

    .contrast-table th, .contrast-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

    .contrast-table th {
      background: var(--bg-alt);
      font-weight: 800;
      color: var(--text-main);
      border-bottom: 2px solid var(--text-main);
    }

    .contrast-table tr:last-child td {
      border-bottom: none;
    }

    .contrast-table .col-highlight {
      background: #EFF6FF;
      font-weight: 700;
      color: var(--accent-electric);
    }

    /* 用户评论卡片 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: #FFFFFF;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: 4px 4px 0px var(--accent-glow);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-quote {
      font-size: 0.95rem;
      color: var(--text-secondary);
      line-height: 1.6;
      margin-bottom: 20px;
      font-style: italic;
    }

    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px dashed var(--border-color);
      padding-top: 12px;
    }

    .user-avatar-tag {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--accent-contrast);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      border: 1.5px solid var(--text-main);
    }

    .user-meta h5 {
      font-size: 0.95rem;
      font-weight: 800;
    }

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

    /* 折叠面板 FAQ */
    .faq-wrapper {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      border: 2px solid var(--text-main);
      border-radius: var(--radius-sm);
      background: #FFFFFF;
      overflow: hidden;
      box-shadow: 3px 3px 0px var(--text-main);
    }

    .faq-header {
      padding: 18px 20px;
      font-weight: 800;
      font-size: 1.05rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #FFFFFF;
      user-select: none;
    }

    .faq-header:hover {
      background: var(--bg-alt);
    }

    .faq-toggle-icon {
      font-size: 1.2rem;
      transition: transform 0.2s;
    }

    .faq-body {
      padding: 0 20px 18px;
      font-size: 0.95rem;
      color: var(--text-secondary);
      line-height: 1.6;
      display: none;
      border-top: 1px dashed var(--border-color);
      padding-top: 14px;
    }

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

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

    /* 表单与联络布局 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      background: #FFFFFF;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: 8px 8px 0px var(--accent-contrast);
    }

    .contact-info-list {
      list-style: none;
      margin-top: 20px;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .contact-info-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      font-size: 0.95rem;
    }

    .contact-qr-wrap {
      margin-top: 20px;
      display: flex;
      align-items: center;
      gap: 20px;
    }

    .contact-qr-wrap img {
      width: 110px;
      height: 110px;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-sm);
    }

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

    .form-group label {
      display: block;
      font-weight: 700;
      margin-bottom: 6px;
      font-size: 0.9rem;
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-sm);
      font-family: inherit;
      font-size: 0.95rem;
      background: var(--bg-alt);
    }

    .form-control:focus {
      outline: none;
      background: #FFFFFF;
      border-color: var(--accent-electric);
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
    }

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

    /* 文章列表与外链 */
    .articles-flex {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      margin-top: 20px;
    }

    .article-item {
      background: #FFFFFF;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-sm);
      padding: 16px;
      box-shadow: 3px 3px 0px var(--text-main);
    }

    .article-item a {
      font-weight: 700;
      color: var(--text-main);
      text-decoration: none;
      font-size: 0.95rem;
      line-height: 1.5;
    }

    .article-item a:hover {
      color: var(--accent-electric);
      text-decoration: underline;
    }

    /* 页脚 */
    .site-footer {
      background-color: var(--text-main);
      color: #FFFFFF;
      border-top: 3px solid var(--accent-glow);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: var(--accent-glow);
      font-size: 1.1rem;
      margin-bottom: 16px;
      font-weight: 800;
    }

    .footer-col p {
      color: #94A3B8;
      font-size: 0.9rem;
      line-height: 1.6;
    }

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

    .footer-links li {
      margin-bottom: 8px;
    }

    .footer-links a {
      color: #CBD5E1;
      text-decoration: none;
      font-size: 0.9rem;
      transition: color 0.2s;
    }

    .footer-links a:hover {
      color: var(--accent-contrast);
    }

    .footer-bottom {
      border-top: 1px solid #334155;
      padding-top: 24px;
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
      gap: 16px;
      font-size: 0.85rem;
      color: #94A3B8;
    }

    .friend-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      align-items: center;
    }

    .friend-links-wrap a {
      color: #CBD5E1;
      text-decoration: none;
      font-size: 0.85rem;
    }

    .friend-links-wrap a:hover {
      color: var(--accent-glow);
    }

    /* 悬浮客服挂件 */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      background: #FFFFFF;
      border: 2px solid var(--text-main);
      border-radius: var(--radius-md);
      padding: 12px;
      box-shadow: 4px 4px 0px var(--accent-contrast);
      text-align: center;
      cursor: pointer;
    }

    .floating-kefu p {
      font-size: 0.75rem;
      font-weight: 800;
      margin-top: 4px;
    }

    /* 响应式断点 */
    @media (max-width: 992px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .cards-grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .cards-grid-3, .testimonials-grid, .articles-flex {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-container {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-toggle {
        display: block;
      }
      .nav-menu {
        display: none;
        position: absolute;
        top: 76px;
        left: 0;
        right: 0;
        background: #FFFFFF;
        border-bottom: 2px solid var(--text-main);
        padding: 20px;
        box-shadow: var(--shadow-md);
      }
      .nav-menu.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 0;
      }
      .hero-content h1 {
        font-size: 2rem;
      }
      .cards-grid-4, .cards-grid-3, .cards-grid-2, .testimonials-grid, .steps-container, .articles-flex {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-stats-row {
        flex-direction: column;
        gap: 12px;
      }
      .floating-kefu {
        bottom: 15px;
        right: 15px;
        padding: 8px;
      }
    }