:root {
      --primary: #1E40AF;
      --primary-hover: #1D4ED8;
      --primary-light: #EFF6FF;
      --accent: #2563EB;
      --accent-bright: #3B82F6;
      --text-main: #0F172A;
      --text-sub: #475569;
      --text-muted: #64748B;
      --bg-page: #F8FAFC;
      --bg-card: #FFFFFF;
      --border-color: #E2E8F0;
      --highlight: #F59E0B;
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.06);
      --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.08);
      --shadow-lg: 0 12px 28px -6px rgba(30, 64, 175, 0.12);
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 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, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .ai-container {
      width: 100%;
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    .ai-section {
      padding: 80px 0;
      position: relative;
    }

    .ai-section-alt {
      background-color: #F1F5F9;
    }

    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 50px auto;
    }

    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      background-color: var(--primary-light);
      color: var(--primary);
      font-size: 0.875rem;
      font-weight: 600;
      border-radius: 9999px;
      margin-bottom: 12px;
      border: 1px solid #DBEAFE;
    }

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

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

    /* Header & Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background-color: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

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

    .ai-page-logo {
      height: 38px;
      width: auto;
      object-fit: contain;
    }

    .brand-text {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: 0.5px;
    }

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

    .nav-links li a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-sub);
      padding: 8px 14px;
      border-radius: var(--radius-sm);
      display: block;
    }

    .nav-links li 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;
      padding: 10px 22px;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius-md);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      text-align: center;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #FFFFFF;
      box-shadow: 0 4px 14px rgba(30, 64, 175, 0.25);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(30, 64, 175, 0.35);
    }

    .btn-outline {
      background-color: #FFFFFF;
      border-color: #CBD5E1;
      color: var(--text-main);
    }

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

    .btn-sm {
      padding: 6px 14px;
      font-size: 0.875rem;
    }

    .btn-lg {
      padding: 14px 32px;
      font-size: 1.1rem;
    }

    .nav-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }

    .nav-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-main);
      margin: 5px 0;
      transition: var(--transition);
    }

    /* Hero Section (No images, Pure CSS tech styling) */
    .hero-section {
      background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 40%, #F8FAFC 100%);
      padding: 90px 0 80px 0;
      position: relative;
      overflow: hidden;
      border-bottom: 1px solid #BFDBFE;
    }

    .hero-inner {
      text-align: center;
      max-width: 900px;
      margin: 0 auto;
      position: relative;
      z-index: 2;
    }

    .hero-tag {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background-color: #FFFFFF;
      color: var(--primary);
      border-radius: 9999px;
      font-size: 0.9rem;
      font-weight: 700;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
      border: 1px solid #BFDBFE;
    }

    .hero-title {
      font-size: 2.8rem;
      font-weight: 900;
      color: #0F172A;
      line-height: 1.25;
      margin-bottom: 24px;
      letter-spacing: -1px;
    }

    .hero-title span {
      color: var(--primary);
    }

    .hero-desc {
      font-size: 1.2rem;
      color: var(--text-sub);
      line-height: 1.7;
      margin-bottom: 36px;
      max-width: 780px;
      margin-left: auto;
      margin-right: auto;
    }

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

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 20px;
    }

    .stat-card {
      background: #FFFFFF;
      border: 1px solid #DBEAFE;
      padding: 20px 16px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .stat-num {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }

    .stat-label {
      font-size: 0.875rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* Grid & Cards */
    .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: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .feature-icon-badge {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.3rem;
      font-weight: 700;
      margin-bottom: 20px;
      border: 1px solid #DBEAFE;
    }

    .feature-card h3 {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

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

    /* Scene Workshop Badges */
    .scene-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 22px;
      transition: var(--transition);
      position: relative;
    }

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

    .scene-badge {
      font-size: 0.75rem;
      font-weight: 700;
      color: var(--primary);
      background: var(--primary-light);
      padding: 2px 8px;
      border-radius: 4px;
      display: inline-block;
      margin-bottom: 10px;
    }

    .scene-card h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .scene-card p {
      font-size: 0.88rem;
      color: var(--text-sub);
      line-height: 1.5;
    }

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

    .process-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px 20px;
      text-align: center;
      position: relative;
    }

    .process-step {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary);
      color: #FFFFFF;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px auto;
      box-shadow: 0 4px 10px rgba(30, 64, 175, 0.3);
    }

    .process-card h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .process-card p {
      font-size: 0.9rem;
      color: var(--text-sub);
    }

    /* Comparison Table Section */
    .compare-wrap {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .compare-header-card {
      background: linear-gradient(135deg, #1E40AF, #1D4ED8);
      color: #FFFFFF;
      padding: 24px 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 16px;
    }

    .rating-badge {
      display: flex;
      align-items: center;
      gap: 10px;
      background: rgba(255, 255, 255, 0.15);
      padding: 8px 18px;
      border-radius: 9999px;
      backdrop-filter: blur(5px);
    }

    .stars {
      color: var(--highlight);
      font-size: 1.2rem;
      letter-spacing: 2px;
    }

    .score-text {
      font-weight: 800;
      font-size: 1.1rem;
    }

    .table-responsive {
      width: 100%;
      overflow-x: auto;
    }

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

    .compare-table th, .compare-table td {
      padding: 18px 24px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

    .compare-table th {
      background: #F8FAFC;
      color: var(--text-main);
      font-weight: 700;
    }

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

    .compare-table .highlight-col {
      background: #EFF6FF;
      font-weight: 600;
      color: var(--primary);
    }

    /* Media & Cases */
    .media-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .media-img-wrap {
      aspect-ratio: 16 / 9;
      background: #E2E8F0;
      overflow: hidden;
    }

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

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

    .media-body {
      padding: 22px;
    }

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

    .media-body p {
      font-size: 0.9rem;
      color: var(--text-sub);
    }

    /* Model Encyclopedia Cloud */
    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-tag {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: 9999px;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .model-tag:hover {
      background: var(--primary);
      color: #FFFFFF;
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    /* Testimonials */
    .review-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 26px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-stars {
      color: var(--highlight);
      font-size: 0.95rem;
      margin-bottom: 12px;
    }

    .review-content {
      font-size: 0.95rem;
      color: var(--text-sub);
      line-height: 1.6;
      margin-bottom: 20px;
      flex-grow: 1;
    }

    .review-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #F1F5F9;
      padding-top: 14px;
    }

    .author-avatar {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1rem;
    }

    .author-info h5 {
      font-size: 0.95rem;
      font-weight: 700;
    }

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

    /* FAQ Accordion */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 18px 24px;
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      user-select: none;
      transition: var(--transition);
    }

    .faq-question:hover {
      color: var(--primary);
      background-color: #F8FAFC;
    }

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

    .faq-answer {
      display: none;
      padding: 0 24px 20px 24px;
      font-size: 0.95rem;
      color: var(--text-sub);
      line-height: 1.6;
      border-top: 1px solid transparent;
    }

    .faq-item.active .faq-answer {
      display: block;
      border-top-color: #F1F5F9;
    }

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

    /* Forms & Contact Section */
    .form-wrap {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-md);
    }

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

    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      color: var(--text-main);
      background: #F8FAFC;
      transition: var(--transition);
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #FFFFFF;
      box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.15);
    }

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

    .contact-info-card {
      background: linear-gradient(135deg, #1E40AF 0%, #172554 100%);
      color: #FFFFFF;
      border-radius: var(--radius-lg);
      padding: 36px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .contact-item {
      margin-bottom: 20px;
    }

    .contact-label {
      font-size: 0.85rem;
      color: #93C5FD;
      margin-bottom: 4px;
    }

    .contact-val {
      font-size: 1.1rem;
      font-weight: 700;
    }

    .qr-box {
      background: #FFFFFF;
      padding: 16px;
      border-radius: var(--radius-md);
      display: inline-block;
      text-align: center;
      color: var(--text-main);
      margin-top: 10px;
    }

    .qr-box img {
      width: 140px;
      height: 140px;
      margin: 0 auto 8px auto;
      object-fit: contain;
    }

    /* Articles / News List */
    .article-list {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
    }

    .article-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      padding: 16px 20px;
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: var(--transition);
    }

    .article-item:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-sm);
      transform: translateX(4px);
    }

    .article-item-title {
      font-weight: 600;
      color: var(--text-main);
      font-size: 0.95rem;
    }

    /* Footer */
    .site-footer {
      background: #0F172A;
      color: #94A3B8;
      padding: 60px 0 30px 0;
      border-top: 1px solid #1E293B;
    }

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

    .footer-col h4 {
      color: #F8FAFC;
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 18px;
    }

    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .footer-links a {
      color: #94A3B8;
      font-size: 0.9rem;
    }

    .footer-links a:hover {
      color: #60A5FA;
    }

    .friend-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 10px;
    }

    .friend-links-wrap a {
      color: #94A3B8;
      font-size: 0.875rem;
      background: #1E293B;
      padding: 4px 10px;
      border-radius: 4px;
      display: inline-block;
    }

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

    .footer-bottom {
      border-top: 1px solid #1E293B;
      padding-top: 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.85rem;
    }

    /* Floating Widget */
    .floating-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #FFFFFF;
      color: var(--primary);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.1rem;
      cursor: pointer;
      transition: var(--transition);
    }

    .float-btn:hover {
      background: var(--primary);
      color: #FFFFFF;
      transform: scale(1.08);
    }

    /* Responsive */
    @media (max-width: 992px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .grid-4, .hero-stats-grid, .process-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .article-list {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .site-header {
        padding: 0 10px;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #FFFFFF;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-toggle {
        display: block;
      }
      .grid-2, .grid-3, .grid-4, .hero-stats-grid, .process-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 1.85rem;
      }
      .hero-desc {
        font-size: 1rem;
      }
      .section-title {
        font-size: 1.6rem;
      }
      .form-wrap, .contact-info-card {
        padding: 24px;
      }
    }