:root {
      --primary-red: #d32f2f;
      --primary-crimson: #b71c1c;
      --accent-gold: #e65100;
      --light-red-bg: #fff5f5;
      --card-border: #fce4e4;
      --text-main: #1f1f1f;
      --text-muted: #5f5f5f;
      --text-light: #8c8c8c;
      --bg-warm-light: #faf7f7;
      --white: #ffffff;
      --shadow-sm: 0 4px 12px rgba(183, 28, 28, 0.06);
      --shadow-md: 0 8px 24px rgba(183, 28, 28, 0.12);
      --shadow-lg: 0 16px 36px rgba(183, 28, 28, 0.16);
      --radius: 12px;
      --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    }

    * {
      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-warm-light);
      color: var(--text-main);
      line-height: 1.65;
      overflow-x: hidden;
    }

    /* 容器规范 */
    .site-container {
      width: 100%;
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 顶部导航 */
    header.site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--card-border);
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
    }

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

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

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

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

    .nav-links li a {
      color: var(--text-main);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      padding: 8px 12px;
      border-radius: 6px;
      transition: var(--transition);
      display: inline-block;
    }

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

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

    .btn-header {
      background: linear-gradient(135deg, var(--primary-red), var(--primary-crimson));
      color: var(--white) !important;
      padding: 9px 20px;
      border-radius: 8px;
      font-weight: 600;
      font-size: 0.9rem;
      text-decoration: none;
      box-shadow: 0 4px 14px rgba(211, 47, 47, 0.28);
      transition: var(--transition);
      display: inline-block;
    }

    .btn-header:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(211, 47, 47, 0.4);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: 1px solid var(--card-border);
      padding: 8px;
      border-radius: 6px;
      cursor: pointer;
      color: var(--primary-red);
    }

    /* 区域通用样式 */
    section.page-section {
      padding: 80px 0;
      border-bottom: 1px solid rgba(211, 47, 47, 0.05);
    }

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

    .section-tag {
      display: inline-block;
      padding: 4px 16px;
      background: var(--light-red-bg);
      color: var(--primary-red);
      border: 1px solid var(--card-border);
      font-size: 0.85rem;
      font-weight: 600;
      border-radius: 50px;
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }

    .section-subtitle {
      font-size: 1.05rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 首屏 Hero */
    .hero-section {
      background: radial-gradient(circle at 50% 20%, #ffebee 0%, #fffaf9 60%, var(--bg-warm-light) 100%);
      padding: 100px 0 80px 0;
      text-align: center;
      position: relative;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: #ffffff;
      border: 1px solid #ffcdd2;
      border-radius: 30px;
      color: var(--primary-crimson);
      font-size: 0.9rem;
      font-weight: 600;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }

    .hero-h1 {
      font-size: 2.7rem;
      font-weight: 900;
      color: #990000;
      line-height: 1.25;
      margin-bottom: 22px;
    }

    .hero-lead {
      font-size: 1.2rem;
      color: var(--text-muted);
      max-width: 860px;
      margin: 0 auto 36px auto;
    }

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

    .btn-main-hero {
      background: linear-gradient(135deg, #e53935, #b71c1c);
      color: #ffffff;
      font-size: 1.1rem;
      font-weight: 700;
      padding: 16px 36px;
      border-radius: 10px;
      text-decoration: none;
      box-shadow: 0 8px 24px rgba(183, 28, 28, 0.35);
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-main-hero:hover {
      transform: translateY(-3px);
      box-shadow: 0 12px 30px rgba(183, 28, 28, 0.45);
    }

    .btn-sub-hero {
      background: #ffffff;
      color: var(--text-main);
      font-size: 1.05rem;
      font-weight: 600;
      padding: 16px 32px;
      border-radius: 10px;
      text-decoration: none;
      border: 1px solid #e0e0e0;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .btn-sub-hero:hover {
      border-color: var(--primary-red);
      color: var(--primary-red);
    }

    /* 首屏数据指标卡 */
    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1060px;
      margin: 0 auto;
    }

    .stat-card {
      background: #ffffff;
      padding: 24px 16px;
      border-radius: var(--radius);
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
    }

    .stat-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #ef9a9a;
    }

    .stat-number {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--primary-crimson);
      margin-bottom: 4px;
    }

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

    /* 聚合模型标签墙 */
    .model-badge-wrapper {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
      margin-top: 25px;
    }

    .model-chip {
      background: #ffffff;
      border: 1px solid #ffd8d8;
      padding: 6px 14px;
      border-radius: 6px;
      font-size: 0.85rem;
      font-weight: 600;
      color: #5c1818;
      box-shadow: 0 2px 6px rgba(0,0,0,0.02);
    }

    /* 通用网格与卡片 */
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

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

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

    .feature-card {
      background: #ffffff;
      border-radius: var(--radius);
      padding: 30px 24px;
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      height: 100%;
    }

    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: #e57373;
    }

    .card-icon-box {
      width: 52px;
      height: 52px;
      border-radius: 12px;
      background: var(--light-red-bg);
      color: var(--primary-red);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 20px;
      font-weight: bold;
    }

    .feature-card h3 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .feature-card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.6;
      flex-grow: 1;
    }

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

    .step-card {
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: var(--radius);
      padding: 28px 20px;
      box-shadow: var(--shadow-sm);
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--primary-crimson);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1rem;
      margin-bottom: 16px;
    }

    .step-card h4 {
      font-size: 1.15rem;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .step-card p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 案例展示区（含图片） */
    .case-card {
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #f0f0f0;
      overflow: hidden;
    }

    .case-img-wrap.square-wrap {
      aspect-ratio: 1 / 1;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.5s ease;
    }

    .case-card:hover .case-img-wrap img {
      transform: scale(1.04);
    }

    .case-body {
      padding: 22px;
    }

    .case-badge {
      display: inline-block;
      font-size: 0.75rem;
      color: var(--primary-red);
      background: var(--light-red-bg);
      padding: 3px 8px;
      border-radius: 4px;
      font-weight: 600;
      margin-bottom: 10px;
    }

    .case-body h4 {
      font-size: 1.15rem;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .case-body p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 评测与对比表格 */
    .rating-banner {
      background: linear-gradient(135deg, #b71c1c, #d32f2f);
      border-radius: var(--radius);
      padding: 36px;
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 40px;
      box-shadow: var(--shadow-md);
      flex-wrap: wrap;
      gap: 24px;
    }

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

    .rating-number {
      font-size: 3.5rem;
      font-weight: 900;
      line-height: 1;
      color: #ffe082;
    }

    .rating-text h3 {
      font-size: 1.4rem;
      margin-bottom: 4px;
    }

    .rating-text p {
      font-size: 0.95rem;
      opacity: 0.9;
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
    }

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }

    .compare-table th,
    .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid #f0f0f0;
      font-size: 0.95rem;
    }

    .compare-table th {
      background: #fff8f8;
      color: var(--text-main);
      font-weight: 700;
    }

    .compare-table tr:hover {
      background: #fffcfc;
    }

    .highlight-cell {
      color: var(--primary-crimson);
      font-weight: 700;
      background: rgba(255, 245, 245, 0.6);
    }

    /* 用户评论 */
    .review-card {
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

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

    .user-avatar-circle {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: #ffebee;
      color: var(--primary-crimson);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.1rem;
    }

    .user-info h4 {
      font-size: 1rem;
      color: var(--text-main);
    }

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

    .review-card p {
      font-size: 0.92rem;
      color: var(--text-main);
      line-height: 1.6;
      font-style: normal;
    }

    /* 表单区域 */
    .form-box {
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-md);
      max-width: 800px;
      margin: 0 auto;
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 600;
      color: var(--text-main);
      font-size: 0.95rem;
    }

    .form-control {
      width: 100%;
      padding: 13px 16px;
      border: 1px solid #d9d9d9;
      border-radius: 8px;
      font-size: 0.95rem;
      outline: none;
      transition: var(--transition);
      background: #ffffff;
      color: var(--text-main);
    }

    .form-control:focus {
      border-color: var(--primary-red);
      box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.12);
    }

    .form-submit-btn {
      width: 100%;
      background: linear-gradient(135deg, var(--primary-red), var(--primary-crimson));
      color: #ffffff;
      border: none;
      padding: 15px;
      font-size: 1.05rem;
      font-weight: 700;
      border-radius: 8px;
      cursor: pointer;
      box-shadow: 0 6px 18px rgba(211, 47, 47, 0.3);
      transition: var(--transition);
    }

    .form-submit-btn:hover {
      opacity: 0.95;
      transform: translateY(-2px);
    }

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

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--card-border);
      border-radius: 8px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-header {
      padding: 18px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-weight: 600;
      font-size: 1.02rem;
      color: var(--text-main);
      background: #ffffff;
      transition: background-color 0.2s;
    }

    .faq-header:hover {
      background: #fffafa;
    }

    .faq-icon {
      font-size: 1.2rem;
      color: var(--primary-red);
      transition: transform 0.3s ease;
    }

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

    .faq-body {
      padding: 0 24px 20px 24px;
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.65;
      display: none;
      border-top: 1px solid #f9ecec;
      padding-top: 14px;
    }

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

    /* 文章与资讯链接 */
    .article-links-wrap {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--card-border);
      margin-top: 20px;
    }

    .article-links-wrap ul {
      list-style: none;
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 12px;
    }

    .article-links-wrap li a {
      color: var(--text-main);
      text-decoration: none;
      font-size: 0.92rem;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: var(--transition);
    }

    .article-links-wrap li a:hover {
      color: var(--primary-red);
      text-decoration: underline;
    }

    /* 底部通用规范 */
    footer.site-footer {
      background: #1a1a1a;
      color: #e0e0e0;
      padding: 60px 0 30px 0;
      border-top: 4px solid var(--primary-red);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1.1rem;
      margin-bottom: 18px;
      font-weight: 700;
      position: relative;
      padding-bottom: 8px;
    }

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

    .footer-col p {
      font-size: 0.9rem;
      color: #a0a0a0;
      line-height: 1.7;
      margin-bottom: 8px;
    }

    .footer-links-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .footer-links-list li a {
      color: #b0b0b0;
      text-decoration: none;
      font-size: 0.9rem;
      transition: var(--transition);
    }

    .footer-links-list li a:hover {
      color: #ffffff;
      padding-left: 4px;
    }

    .qr-container {
      display: flex;
      align-items: center;
      gap: 14px;
      background: #262626;
      padding: 12px;
      border-radius: 8px;
      max-width: 240px;
    }

    .qr-container img {
      width: 76px;
      height: 76px;
      object-fit: cover;
      border-radius: 4px;
      background: #ffffff;
    }

    .qr-text {
      font-size: 0.8rem;
      color: #b0b0b0;
      line-height: 1.4;
    }

    .footer-bottom-bar {
      border-top: 1px solid #333333;
      padding-top: 24px;
      text-align: center;
      font-size: 0.85rem;
      color: #888888;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
    }

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

    .footer-friendly-links a {
      color: #888888;
      text-decoration: none;
      font-size: 0.85rem;
      transition: var(--transition);
    }

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

    /* 浮动工具栏 */
    .floating-tools {
      position: fixed;
      right: 20px;
      bottom: 40px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      z-index: 999;
    }

    .floating-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #ffffff;
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-md);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      color: var(--primary-red);
      font-weight: bold;
      text-decoration: none;
      transition: var(--transition);
    }

    .floating-btn:hover {
      background: var(--primary-red);
      color: #ffffff;
      transform: scale(1.08);
    }

    /* 响应式断点 */
    @media (max-width: 992px) {
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-4, .process-step-list {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .mobile-menu-btn {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        border-bottom: 1px solid #f0f0f0;
      }
      .nav-links.show {
        display: flex;
      }
      .nav-links li {
        width: 100%;
        text-align: center;
      }
      .hero-h1 {
        font-size: 1.95rem;
      }
      .grid-2, .grid-3, .grid-4, .process-step-list {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .rating-banner {
        flex-direction: column;
        text-align: center;
      }
      .rating-score-box {
        flex-direction: column;
      }
      .footer-bottom-bar {
        flex-direction: column;
        text-align: center;
      }
    }