:root {
      --primary: #0284c7;
      --primary-dark: #0369a1;
      --primary-light: #e0f2fe;
      --accent: #2563eb;
      --accent-warm: #f97316;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
      --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
      --radius: 12px;
    }

    * {
      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, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
      padding-top: 72px;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: all 0.2s ease;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

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

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

    .section-tag {
      display: inline-block;
      padding: 4px 12px;
      background: var(--primary-light);
      color: var(--primary-dark);
      font-size: 0.875rem;
      font-weight: 600;
      border-radius: 9999px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }

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

    /* Header Nav */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      height: 72px;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

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

    .brand-logo-box {
      display: flex;
      align-items: center;
      height: 40px;
    }

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

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

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

    .nav-item a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 14px;
      border-radius: 6px;
      display: inline-block;
    }

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

    .nav-action {
      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: 8px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      white-space: nowrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: #ffffff !important;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.25);
    }

    .btn-primary:hover {
      box-shadow: 0 6px 18px rgba(2, 132, 199, 0.4);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: #ffffff;
      border-color: var(--border-color);
      color: var(--text-main) !important;
    }

    .btn-outline:hover {
      background: var(--bg-page);
      border-color: var(--primary);
      color: var(--primary) !important;
    }

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

    /* Hero Section */
    .hero-section {
      padding: 80px 0 60px 0;
      background: radial-gradient(circle at 50% 10%, rgba(224, 242, 254, 0.8) 0%, rgba(248, 250, 252, 1) 70%);
      text-align: center;
      position: relative;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid #bae6fd;
      border-radius: 9999px;
      font-size: 0.875rem;
      color: var(--primary-dark);
      font-weight: 600;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }

    .hero-title {
      font-size: 3.2rem;
      font-weight: 900;
      color: var(--text-main);
      line-height: 1.2;
      margin-bottom: 24px;
      letter-spacing: -1px;
    }

    .hero-title-highlight {
      background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-subtitle {
      font-size: 1.25rem;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px auto;
      line-height: 1.6;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 48px;
    }

    .hero-actions .btn {
      padding: 14px 32px;
      font-size: 1.05rem;
    }

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1000px;
      margin: 0 auto;
      text-align: left;
    }

    .stat-card {
      background: #ffffff;
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .stat-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #bae6fd;
    }

    .stat-num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
      font-variant-numeric: tabular-nums;
    }

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

    /* Grid Layouts */
    .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: 32px;
    }

    /* Cards */
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }

    .feature-card:hover {
      border-color: #bae6fd;
      transform: translateY(-5px);
      box-shadow: var(--shadow-lg);
    }

    .feature-icon-box {
      width: 52px;
      height: 52px;
      border-radius: 10px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 20px;
      font-weight: 700;
    }

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

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

    .feature-footer-tag {
      margin-top: 18px;
      display: inline-block;
      font-size: 0.8rem;
      font-weight: 600;
      color: var(--primary);
      background: #f0f9ff;
      padding: 3px 8px;
      border-radius: 4px;
      align-self: flex-start;
    }

    /* Model Cloud Banner */
    .model-badge-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 20px;
    }

    .model-pill {
      background: #f1f5f9;
      color: var(--text-main);
      padding: 8px 16px;
      border-radius: 9999px;
      font-size: 0.875rem;
      font-weight: 600;
      border: 1px solid #e2e8f0;
      transition: all 0.2s;
    }

    .model-pill:hover {
      background: var(--primary-light);
      color: var(--primary-dark);
      border-color: #bae6fd;
    }

    /* Review Table */
    .table-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }

    .custom-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.95rem;
    }

    .custom-table th, .custom-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }

    .custom-table th {
      background: #f8fafc;
      font-weight: 700;
      color: var(--text-main);
    }

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

    .badge-highlight {
      display: inline-block;
      padding: 4px 10px;
      background: #dcfce7;
      color: #15803d;
      border-radius: 6px;
      font-weight: 600;
      font-size: 0.85rem;
    }

    .badge-normal {
      display: inline-block;
      padding: 4px 10px;
      background: #f1f5f9;
      color: var(--text-muted);
      border-radius: 6px;
      font-size: 0.85rem;
    }

    /* Steps Flow */
    .flow-steps {
      display: flex;
      gap: 20px;
      position: relative;
    }

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

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

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

    .step-item p {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* Case Section */
    .case-card {
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .case-img-box {
      width: 100%;
      aspect-ratio: 16/9;
      background: #e2e8f0;
      overflow: hidden;
    }

    .case-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

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

    .case-info {
      padding: 20px;
    }

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

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

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

    .testimonial-header {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
    }

    .user-avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #e0f2fe;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.1rem;
    }

    .user-meta h4 {
      font-size: 1rem;
      font-weight: 700;
    }

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

    .testimonial-quote {
      font-size: 0.925rem;
      color: var(--text-muted);
      line-height: 1.6;
      font-style: italic;
    }

    /* FAQ Accordion */
    .faq-wrapper {
      max-width: 860px;
      margin: 0 auto;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
      transition: border-color 0.2s;
    }

    .faq-item:hover {
      border-color: #bae6fd;
    }

    .faq-question {
      padding: 20px 24px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.05rem;
      color: var(--text-main);
      user-select: none;
    }

    .faq-arrow {
      font-size: 0.85rem;
      transition: transform 0.3s ease;
      color: var(--text-light);
    }

    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      padding: 0 24px;
      background: #fafafa;
    }

    .faq-item.active .faq-answer {
      padding: 16px 24px 20px 24px;
      max-height: 300px;
      border-top: 1px solid #f1f5f9;
    }

    .faq-answer p {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* Form & Contact */
    .contact-form-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 40px;
      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: 8px;
      font-size: 0.95rem;
      background: #f8fafc;
      transition: border-color 0.2s, background 0.2s;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
    }

    .contact-info-panel {
      display: flex;
      flex-direction: column;
      justify-content: center;
      gap: 24px;
    }

    .contact-info-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .contact-qr-img {
      width: 90px;
      height: 90px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      object-fit: cover;
    }

    /* Article Links & Badges */
    .article-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }

    .article-chip {
      padding: 8px 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 6px;
      font-size: 0.875rem;
      color: var(--primary-dark);
      font-weight: 500;
      transition: all 0.2s;
    }

    .article-chip:hover {
      border-color: var(--primary);
      background: var(--primary-light);
    }

    /* 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 h5 {
      color: #f8fafc;
      font-size: 1rem;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .footer-col p {
      font-size: 0.9rem;
      line-height: 1.6;
      margin-bottom: 12px;
    }

    .footer-links-list {
      list-style: none;
      font-size: 0.9rem;
    }

    .footer-links-list li {
      margin-bottom: 10px;
    }

    .footer-links-list a {
      color: #94a3b8;
    }

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

    .friend-links-box {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      margin-bottom: 24px;
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      align-items: center;
      font-size: 0.85rem;
    }

    .friend-links-box a {
      color: #64748b;
    }

    .friend-links-box a:hover {
      color: #38bdf8;
    }

    .copyright-bar {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      font-size: 0.85rem;
      color: #64748b;
    }

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

    .float-btn {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: #ffffff;
      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;
      color: var(--text-main);
      transition: all 0.2s;
    }

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

    /* Responsive */
    @media (max-width: 992px) {
      .grid-4, .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .flow-steps {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
      .site-header.menu-open .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        box-shadow: var(--shadow-md);
      }
      .nav-item a {
        width: 100%;
      }
    }

    @media (max-width: 640px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .grid-4, .grid-3, .grid-2 {
        grid-template-columns: 1fr;
      }
      .hero-stats-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .contact-form-box {
        padding: 24px;
      }
    }