:root {
      --primary: #1e40af;
      --primary-hover: #1d4ed8;
      --primary-light: #eff6ff;
      --accent: #2563eb;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-surface: #ffffff;
      --border-color: #e2e8f0;
      --border-focus: #93c5fd;
      --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --card-hover-shadow: 0 10px 15px -3px rgba(30, 64, 175, 0.1), 0 4px 6px -4px rgba(30, 64, 175, 0.05);
      --container-max: 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", Arial, "Noto Sans", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--container-max);
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
      width: 100%;
    }

    /* 顶部导航 */
    header.site-header {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      position: sticky;
      top: 0;
      z-index: 1000;
      border-bottom: 1px solid var(--border-color);
    }

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

    .brand-wrap {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
    }

    .logo-container {
      width: 130px;
      display: flex;
      align-items: center;
    }

    .logo-container img {
      max-width: 100%;
      height: auto;
      display: block;
    }

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

    .nav-links a {
      text-decoration: none;
      color: var(--text-main);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 8px 12px;
      border-radius: 6px;
      transition: color 0.2s ease, background-color 0.2s ease;
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      padding: 10px 20px;
      border-radius: 8px;
      text-decoration: none;
      transition: all 0.2s ease;
      cursor: pointer;
      border: 1px solid transparent;
      font-size: 0.95rem;
      text-align: center;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff;
      box-shadow: 0 2px 4px rgba(30, 64, 175, 0.2);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-1px);
      box-shadow: 0 4px 8px rgba(30, 64, 175, 0.3);
    }

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

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

    .btn-large {
      padding: 14px 28px;
      font-size: 1.05rem;
    }

    .nav-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
      padding: 4px;
    }

    /* 首屏 Hero (无图片，蓝调渐变背景与几何块) */
    .hero-section {
      background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 50%, #2563eb 100%);
      color: #ffffff;
      padding: 80px 0 90px;
      position: relative;
      overflow: hidden;
    }

    .hero-section::before {
      content: "";
      position: absolute;
      top: -10%;
      right: -5%;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0) 70%);
      border-radius: 50%;
      pointer-events: none;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 40px;
      align-items: center;
      position: relative;
      z-index: 1;
    }

    .hero-content h1 {
      font-size: 2.25rem;
      line-height: 1.3;
      margin-bottom: 20px;
      font-weight: 800;
      letter-spacing: -0.5px;
    }

    .hero-lead {
      font-size: 1.125rem;
      line-height: 1.7;
      color: #e0e7ff;
      margin-bottom: 30px;
    }

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      align-items: center;
      margin-bottom: 32px;
    }

    .hero-actions .btn-primary {
      background: #ffffff;
      color: var(--primary);
    }

    .hero-actions .btn-primary:hover {
      background: #f1f5f9;
      color: var(--primary-hover);
    }

    .hero-actions .btn-outline {
      border-color: #ffffff;
      color: #ffffff;
      background: transparent;
    }

    .hero-actions .btn-outline:hover {
      background: rgba(255, 255, 255, 0.15);
    }

    .hero-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }

    .hero-tag {
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.25);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.85rem;
      color: #f8fafc;
    }

    .hero-stats-panel {
      background: rgba(255, 255, 255, 0.1);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: 16px;
      padding: 30px;
      box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2);
    }

    .stats-item {
      padding: 16px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    }

    .stats-item:last-child {
      border-bottom: none;
      padding-bottom: 0;
    }

    .stats-item:first-child {
      padding-top: 0;
    }

    .stats-value {
      font-size: 1.8rem;
      font-weight: 700;
      color: #ffffff;
      display: flex;
      align-items: baseline;
      gap: 6px;
    }

    .stats-desc {
      font-size: 0.9rem;
      color: #c7d2fe;
      margin-top: 4px;
    }

    /* 通用章节规范 */
    .section-wrap {
      padding: 70px 0;
    }

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

    .section-badge {
      display: inline-block;
      background: var(--primary-light);
      color: var(--primary);
      font-size: 0.85rem;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 16px;
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 1.85rem;
      color: var(--text-main);
      font-weight: 700;
      margin-bottom: 12px;
    }

    .section-intro {
      font-size: 1rem;
      color: var(--text-muted);
    }

    /* 网格卡片系统 */
    .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;
    }

    .card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 24px;
      box-shadow: var(--card-shadow);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
      display: flex;
      flex-direction: column;
    }

    .card:hover {
      transform: translateY(-3px);
      box-shadow: var(--card-hover-shadow);
      border-color: var(--border-focus);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      border-radius: 10px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.4rem;
      margin-bottom: 16px;
      font-weight: bold;
    }

    .card-title {
      font-size: 1.15rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .card-text {
      color: var(--text-muted);
      font-size: 0.925rem;
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 模型矩阵胶囊云 */
    .models-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 24px;
      justify-content: center;
    }

    .model-chip {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: 8px;
      font-size: 0.875rem;
      font-weight: 500;
      color: var(--text-main);
      box-shadow: 0 1px 2px rgba(0,0,0,0.03);
    }

    /* 案例中心展示 */
    .media-card {
      background: var(--bg-surface);
      border-radius: 12px;
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }

    .media-thumb {
      width: 100%;
      height: 220px;
      background: #e2e8f0;
      position: relative;
    }

    .media-thumb img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .media-body {
      padding: 20px;
    }

    .media-title {
      font-size: 1.1rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .media-desc {
      font-size: 0.875rem;
      color: var(--text-muted);
    }

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

    .step-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 24px;
      position: relative;
    }

    .step-num {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      background: var(--primary);
      color: #fff;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 12px;
      font-size: 0.9rem;
    }

    /* 评测与对比表格 */
    .eval-highlight-box {
      background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
      border: 1px solid #bfdbfe;
      border-radius: 12px;
      padding: 24px;
      margin-bottom: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }

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

    .score-num {
      font-size: 2.4rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1;
    }

    .score-stars {
      color: #f59e0b;
      font-size: 1.25rem;
      letter-spacing: 2px;
    }

    .table-responsive {
      width: 100%;
      overflow-x: auto;
      background: var(--bg-surface);
      border-radius: 12px;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
    }

    .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 var(--border-color);
    }

    .compare-table th {
      background: #f1f5f9;
      font-weight: 600;
      color: var(--text-main);
    }

    .compare-table tr:hover td {
      background: #f8fafc;
    }

    .tag-best {
      color: var(--primary);
      font-weight: 600;
    }

    /* 表单组件 */
    .form-container {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 16px;
      padding: 36px;
      box-shadow: var(--card-shadow);
      max-width: 720px;
      margin: 0 auto;
    }

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

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.95rem;
      color: var(--text-main);
      background-color: #ffffff;
      outline: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.15);
    }

    textarea.form-control {
      min-height: 110px;
      resize: vertical;
    }

    /* FAQ 手风琴 */
    .faq-container {
      max-width: 840px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 8px;
      overflow: hidden;
      transition: border-color 0.2s ease;
    }

    .faq-question {
      padding: 16px 20px;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
      background: #ffffff;
    }

    .faq-question:hover {
      background-color: #f8fafc;
    }

    .faq-icon {
      font-size: 1.1rem;
      transition: transform 0.2s ease;
      color: var(--text-muted);
    }

    .faq-answer {
      display: none;
      padding: 0 20px 16px;
      color: var(--text-muted);
      font-size: 0.925rem;
      line-height: 1.6;
      border-top: 1px solid transparent;
    }

    .faq-item.active {
      border-color: var(--border-focus);
    }

    .faq-item.active .faq-answer {
      display: block;
      border-top-color: #f1f5f9;
      padding-top: 14px;
    }

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

    /* 客户评价 */
    .testimonial-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-body {
      font-size: 0.925rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 16px;
      font-style: italic;
    }

    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .author-avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      font-weight: bold;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1rem;
    }

    .author-info h4 {
      font-size: 0.95rem;
      color: var(--text-main);
      margin-bottom: 2px;
    }

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

    /* 文章及知识库 */
    .article-links-wrap {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-row-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 10px 0;
      border-bottom: 1px dashed var(--border-color);
    }

    .article-row-item:last-child {
      border-bottom: none;
    }

    .article-row-item a {
      color: var(--text-main);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.2s ease;
    }

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

    /* 页脚 */
    footer.site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      font-size: 0.9rem;
    }

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

    .footer-brand h3 {
      color: #ffffff;
      font-size: 1.25rem;
      margin-bottom: 16px;
    }

    .footer-brand p {
      line-height: 1.7;
      margin-bottom: 16px;
      max-width: 320px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1rem;
      margin-bottom: 16px;
      font-weight: 600;
    }

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

    .footer-col a {
      color: #94a3b8;
      text-decoration: none;
      transition: color 0.2s ease;
    }

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

    .qr-box {
      width: 110px;
      background: #ffffff;
      padding: 6px;
      border-radius: 6px;
      margin-top: 8px;
    }

    .qr-box img {
      width: 100%;
      height: auto;
      display: block;
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      display: flex;
      flex-direction: column;
      gap: 12px;
      align-items: center;
    }

    .footer-links-inline {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 16px;
    }

    .footer-links-inline a {
      color: #94a3b8;
      text-decoration: none;
    }

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

    /* 浮动侧边栏与返回顶部 */
    .floating-tools {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 990;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--bg-surface);
      color: var(--primary);
      border: 1px solid var(--border-color);
      box-shadow: 0 4px 10px rgba(0,0,0,0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
      font-size: 1.1rem;
      cursor: pointer;
      position: relative;
      transition: transform 0.2s ease, background 0.2s ease;
    }

    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      transform: scale(1.05);
    }

    .float-qr-hover {
      position: absolute;
      right: 56px;
      bottom: 0;
      background: #ffffff;
      padding: 10px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
      display: none;
      width: 130px;
      text-align: center;
    }

    .float-qr-hover img {
      width: 100%;
      height: auto;
      display: block;
    }

    .float-qr-hover span {
      font-size: 0.75rem;
      color: var(--text-muted);
      margin-top: 4px;
      display: block;
    }

    .float-btn-qr:hover .float-qr-hover {
      display: block;
    }

    /* 响应式媒体查询 */
    @media (max-width: 1024px) {
      .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-row {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .grid-3 {
        grid-template-columns: 1fr;
      }
      .grid-2 {
        grid-template-columns: 1fr;
      }
      .steps-row {
        grid-template-columns: 1fr;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 16px 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 10px 15px rgba(0,0,0,0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links a {
        display: block;
        padding: 10px 0;
      }
      .nav-toggle {
        display: block;
      }
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
      }
      .eval-highlight-box {
        flex-direction: column;
        align-items: flex-start;
      }
    }