:root {
      --primary: #c62828;
      --primary-hover: #b71c1c;
      --primary-light: #ffebee;
      --primary-soft: #fff5f5;
      --accent: #d32f2f;
      --accent-gold: #e65100;
      --text-main: #1f2429;
      --text-muted: #5c6b73;
      --text-light: #8d99ae;
      --bg-page: #fbfbfb;
      --bg-card: #ffffff;
      --border-color: #f0d5d5;
      --border-light: #f7e6e6;
      --shadow-sm: 0 2px 8px rgba(198, 40, 40, 0.05);
      --shadow-md: 0 8px 24px rgba(198, 40, 40, 0.08);
      --shadow-lg: 0 16px 36px rgba(198, 40, 40, 0.12);
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 18px;
      --transition: all 0.28s ease;
      --max-width: 1200px;
    }

    * {
      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", "PingFang SC", "Noto Sans", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.65;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }

    ul, ol {
      list-style: none;
    }

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 顶部导航 */
    .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(--border-color);
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }

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

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

    .brand-area .ai-page-logo {
      height: 38px;
      width: auto;
      display: block;
    }

    .brand-text {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: -0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }

    .nav-links a {
      padding: 8px 14px;
      font-size: 0.94rem;
      font-weight: 500;
      color: var(--text-main);
      border-radius: var(--radius-sm);
    }

    .nav-links a:hover {
      color: var(--primary);
      background-color: var(--primary-light);
    }

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

    .btn-nav-primary {
      background: linear-gradient(135deg, var(--accent), var(--primary));
      color: #ffffff !important;
      padding: 8px 18px;
      font-size: 0.92rem;
      font-weight: 600;
      border-radius: var(--radius-md);
      box-shadow: 0 4px 12px rgba(198, 40, 40, 0.25);
    }

    .btn-nav-primary:hover {
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(198, 40, 40, 0.35);
    }

    .nav-toggle {
      display: none;
      background: none;
      border: 1px solid var(--border-color);
      padding: 6px 10px;
      border-radius: var(--radius-sm);
      font-size: 1.2rem;
      color: var(--primary);
      cursor: pointer;
    }

    /* 区域通用样式 */
    .section-padding {
      padding: 72px 0;
    }

    .section-title-wrap {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 48px;
    }

    .section-tag {
      display: inline-block;
      background: var(--primary-light);
      color: var(--primary);
      font-size: 0.82rem;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 30px;
      text-transform: uppercase;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 14px;
    }

    .section-desc {
      font-size: 1rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 首屏 Hero (无图设计) */
    .hero-section {
      background: radial-gradient(circle at 50% 20%, #fff0f0 0%, #ffffff 70%);
      padding: 80px 0 60px;
      border-bottom: 1px solid var(--border-light);
      position: relative;
    }

    .hero-content {
      text-align: center;
      max-width: 920px;
      margin: 0 auto;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--primary);
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }

    .hero-badge-dot {
      width: 8px;
      height: 8px;
      background: var(--accent);
      border-radius: 50%;
      display: inline-block;
    }

    .hero-title {
      font-size: 2.8rem;
      font-weight: 900;
      line-height: 1.25;
      color: #1a1a1a;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-title span {
      color: var(--primary);
      position: relative;
      display: inline-block;
    }

    .hero-subtitle {
      font-size: 1.15rem;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-cta-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }

    .btn-hero-main {
      background: linear-gradient(135deg, #e53935 0%, #b71c1c 100%);
      color: #ffffff;
      font-size: 1.1rem;
      font-weight: 700;
      padding: 14px 34px;
      border-radius: 30px;
      box-shadow: 0 10px 24px rgba(198, 40, 40, 0.35);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-hero-main:hover {
      transform: translateY(-2px);
      box-shadow: 0 14px 28px rgba(198, 40, 40, 0.45);
    }

    .btn-hero-secondary {
      background: #ffffff;
      color: var(--text-main);
      border: 1px solid var(--border-color);
      font-size: 1.1rem;
      font-weight: 600;
      padding: 14px 30px;
      border-radius: 30px;
      box-shadow: var(--shadow-sm);
    }

    .btn-hero-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
      background-color: var(--primary-soft);
    }

    /* 状态与亮点指示条 */
    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: var(--shadow-md);
      text-align: center;
    }

    .metric-item h3 {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
    }

    .metric-item p {
      font-size: 0.88rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 模型矩阵徽章云 */
    .model-cloud {
      margin-top: 36px;
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 8px;
    }

    .model-chip {
      background: var(--primary-soft);
      border: 1px solid var(--border-light);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.82rem;
      font-weight: 600;
      color: #661010;
    }

    /* 通用卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }

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

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

    .card-icon-badge {
      width: 48px;
      height: 48px;
      border-radius: 12px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.2rem;
      margin-bottom: 18px;
    }

    .feature-card h3 {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .feature-card p {
      font-size: 0.92rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 16px;
      flex-grow: 1;
    }

    .card-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
    }

    .card-tag-item {
      font-size: 0.75rem;
      background: #f5f5f7;
      color: #444;
      padding: 2px 8px;
      border-radius: 4px;
      font-weight: 500;
    }

    /* 评测与对比模块 */
    .review-score-banner {
      background: linear-gradient(135deg, #fff7f7, #ffebee);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 32px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
      margin-bottom: 32px;
    }

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

    .score-num {
      font-size: 3.2rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }

    .score-details h4 {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 4px;
    }

    .score-stars {
      color: var(--accent-gold);
      font-size: 1.1rem;
      font-weight: 700;
    }

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

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 640px;
    }

    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-light);
      font-size: 0.94rem;
    }

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

    .compare-table td.highlight-col {
      background: rgba(255, 235, 238, 0.4);
      font-weight: 700;
      color: var(--primary);
    }

    /* 案例展示 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

    .case-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .case-media-wrap {
      width: 100%;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      background: #f0f0f0;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .case-media-wrap.square {
      aspect-ratio: 1 / 1;
      max-height: 280px;
    }

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

    .case-card:hover .case-media-wrap img {
      transform: scale(1.03);
    }

    .case-info {
      padding: 20px;
    }

    .case-info h4 {
      font-size: 1.15rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

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

    /* 流程步骤 */
    .flow-steps {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
    }

    .step-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
      box-shadow: var(--shadow-sm);
    }

    .step-num {
      font-size: 1.8rem;
      font-weight: 900;
      color: var(--primary);
      opacity: 0.3;
      margin-bottom: 8px;
      line-height: 1;
    }

    .step-card h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 6px;
    }

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

    /* 用户评论 */
    .review-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 20px;
    }

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

    .review-text {
      font-size: 0.94rem;
      color: var(--text-main);
      line-height: 1.6;
      margin-bottom: 18px;
    }

    .review-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f2f2f2;
      padding-top: 12px;
    }

    .author-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 0.95rem;
    }

    .author-info h5 {
      font-size: 0.92rem;
      font-weight: 700;
    }

    .author-info span {
      font-size: 0.78rem;
      color: var(--text-muted);
    }

    /* 表单与转化区 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 36px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }

    .contact-info-panel h3 {
      font-size: 1.6rem;
      font-weight: 800;
      margin-bottom: 14px;
      color: var(--primary);
    }

    .contact-info-panel p {
      font-size: 0.95rem;
      color: var(--text-muted);
      margin-bottom: 24px;
    }

    .contact-list {
      display: flex;
      flex-direction: column;
      gap: 14px;
      margin-bottom: 24px;
    }

    .contact-list-item {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 0.92rem;
      color: var(--text-main);
    }

    .contact-list-item strong {
      color: var(--primary);
    }

    .qr-box-wrap {
      display: flex;
      align-items: center;
      gap: 16px;
      background: var(--primary-soft);
      border: 1px dashed var(--border-color);
      border-radius: var(--radius-md);
      padding: 16px;
    }

    .qr-box-wrap img {
      width: 90px;
      height: 90px;
      border-radius: var(--radius-sm);
      display: block;
      background: #fff;
    }

    .qr-box-text h5 {
      font-size: 0.96rem;
      font-weight: 700;
      margin-bottom: 4px;
    }

    .qr-box-text p {
      font-size: 0.82rem;
      color: var(--text-muted);
      margin-bottom: 0;
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      font-size: 0.88rem;
      font-weight: 600;
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      border: 1px solid #dcdcdc;
      border-radius: var(--radius-sm);
      font-size: 0.92rem;
      background: #fafafa;
      transition: var(--transition);
      font-family: inherit;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(198, 40, 40, 0.1);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 90px;
    }

    .btn-submit {
      width: 100%;
      background: linear-gradient(135deg, var(--accent), var(--primary));
      color: #ffffff;
      border: none;
      padding: 14px;
      font-size: 1rem;
      font-weight: 700;
      border-radius: var(--radius-sm);
      cursor: pointer;
      box-shadow: 0 4px 14px rgba(198, 40, 40, 0.25);
      transition: var(--transition);
    }

    .btn-submit:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(198, 40, 40, 0.35);
    }

    /* FAQ 手风琴 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: var(--transition);
    }

    .faq-item.active {
      border-color: var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 18px 22px;
      font-size: 1rem;
      font-weight: 700;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      user-select: none;
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-icon {
      font-size: 1.2rem;
      color: var(--primary);
      transition: transform 0.25s ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background: var(--primary-soft);
    }

    .faq-answer-inner {
      padding: 16px 22px 20px;
      font-size: 0.92rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 资讯与文章 */
    .article-box {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 24px;
      margin-bottom: 24px;
    }

    .article-links-list {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 14px;
    }

    .article-links-list a {
      font-size: 0.88rem;
      color: var(--primary);
      background: var(--primary-light);
      padding: 6px 14px;
      border-radius: 20px;
      font-weight: 500;
    }

    .article-links-list a:hover {
      background: var(--primary);
      color: #ffffff;
    }

    /* 页脚设计 */
    .site-footer {
      background: #191c1f;
      color: #d1d5db;
      padding: 60px 0 24px;
      border-top: 3px solid var(--primary);
      margin-top: 40px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 36px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 18px;
    }

    .footer-col p {
      font-size: 0.88rem;
      line-height: 1.6;
      color: #9ca3af;
      margin-bottom: 12px;
    }

    .footer-links {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .footer-links a {
      font-size: 0.88rem;
      color: #9ca3af;
    }

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

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

    .friend-links-wrap a {
      color: #9ca3af;
      font-size: 0.84rem;
      background: rgba(255, 255, 255, 0.06);
      padding: 4px 10px;
      border-radius: 4px;
    }

    .friend-links-wrap a:hover {
      color: #ffffff;
      background: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding-top: 20px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 12px;
      font-size: 0.82rem;
      color: #6b7280;
    }

    .footer-bottom a {
      color: #9ca3af;
    }

    /* 悬浮客服与置顶 */
    .float-tools {
      position: fixed;
      right: 20px;
      bottom: 24px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      z-index: 999;
    }

    .float-btn {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.1rem;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
      cursor: pointer;
      border: none;
      transition: var(--transition);
    }

    .float-btn:hover {
      transform: scale(1.1);
      background: var(--primary-hover);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 16px 24px;
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-toggle {
        display: block;
      }
      .hero-title {
        font-size: 1.8rem;
      }
      .hero-metrics {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }