:root {
      --primary: #4f46e5;
      --primary-hover: #4338ca;
      --secondary: #06b6d4;
      --accent: #f59e0b;
      --accent-pink: #ec4899;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-surface: #ffffff;
      --bg-alt: #f1f5f9;
      --border-color: #e2e8f0;
      --border-focus: #cbd5e1;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 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);
      --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 24px;
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

    html {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-main);
      background-color: var(--bg-page);
      scroll-behavior: smooth;
    }

    body {
      overflow-x: hidden;
      line-height: 1.6;
      background: radial-gradient(circle at 10% 10%, rgba(79, 70, 229, 0.04) 0%, transparent 40%),
                  radial-gradient(circle at 90% 90%, rgba(6, 182, 212, 0.04) 0%, transparent 40%),
                  var(--bg-page);
    }

    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    header.site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      transition: var(--transition);
    }

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

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

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

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

    .nav-links li a {
      text-decoration: none;
      color: var(--text-muted);
      font-weight: 500;
      font-size: 15px;
      padding: 8px 14px;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }

    .nav-links li a:hover {
      color: var(--primary);
      background: rgba(79, 70, 229, 0.06);
    }

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

    .btn-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      background: linear-gradient(135deg, var(--primary) 0%, #6366f1 100%);
      color: #ffffff !important;
      text-decoration: none;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-md);
      box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3);
      transition: var(--transition);
      border: 1px solid transparent;
      cursor: pointer;
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(79, 70, 229, 0.4);
      background: linear-gradient(135deg, var(--primary-hover) 0%, #4f46e5 100%);
    }

    .btn-secondary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      background: #ffffff;
      color: var(--text-main) !important;
      text-decoration: none;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      cursor: pointer;
    }

    .btn-secondary:hover {
      border-color: var(--primary);
      color: var(--primary) !important;
      background: rgba(79, 70, 229, 0.03);
      transform: translateY(-2px);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: 1px solid var(--border-color);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
      cursor: pointer;
    }

    .mobile-menu-btn svg {
      width: 20px;
      height: 20px;
      fill: var(--text-main);
      display: block;
    }

    /* Hero Section */
    .hero-section {
      padding: 80px 0 60px;
      position: relative;
      overflow: hidden;
      background: linear-gradient(180deg, #ffffff 0%, rgba(241, 245, 249, 0.6) 100%);
      border-bottom: 1px solid var(--border-color);
    }

    .hero-inner {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      position: relative;
      z-index: 2;
    }

    .hero-tag {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: rgba(79, 70, 229, 0.08);
      border: 1px solid rgba(79, 70, 229, 0.15);
      border-radius: 999px;
      color: var(--primary);
      font-size: 14px;
      font-weight: 600;
      margin-bottom: 24px;
    }

    .hero-badge-pulse {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--primary);
      box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.5);
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% { box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.6); }
      70% { box-shadow: 0 0 0 10px rgba(79, 70, 229, 0); }
      100% { box-shadow: 0 0 0 0 rgba(79, 70, 229, 0); }
    }

    .hero-title {
      font-size: 46px;
      line-height: 1.25;
      font-weight: 800;
      color: var(--text-main);
      max-width: 900px;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-title span {
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-desc {
      font-size: 18px;
      line-height: 1.7;
      color: var(--text-muted);
      max-width: 780px;
      margin-bottom: 36px;
    }

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

    .btn-hero-official {
      padding: 14px 34px;
      font-size: 16px;
      background: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
      box-shadow: 0 10px 25px rgba(79, 70, 229, 0.35);
    }

    .btn-hero-official:hover {
      box-shadow: 0 12px 30px rgba(6, 182, 212, 0.45);
      transform: translateY(-2px);
    }

    .hero-feature-pills {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 12px;
      max-width: 860px;
    }

    .pill-item {
      padding: 6px 14px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 999px;
      font-size: 13px;
      color: var(--text-muted);
      font-weight: 500;
      box-shadow: var(--shadow-sm);
    }

    /* General Section Styling */
    section {
      padding: 80px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 56px auto;
    }

    .section-subtitle {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary);
      margin-bottom: 8px;
      display: block;
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* Metrics Grid */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: -30px;
      position: relative;
      z-index: 10;
    }

    .metric-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px 24px;
      text-align: center;
      box-shadow: var(--shadow-md);
      transition: var(--transition);
    }

    .metric-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-xl);
      border-color: rgba(79, 70, 229, 0.3);
    }

    .metric-value {
      font-size: 36px;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 6px;
      font-feature-settings: "tnum";
    }

    .metric-label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .metric-sub {
      font-size: 12px;
      color: var(--text-light);
    }

    /* Platform Overview */
    .overview-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .overview-content h3 {
      font-size: 26px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 20px;
      line-height: 1.4;
    }

    .overview-content p {
      color: var(--text-muted);
      font-size: 15px;
      margin-bottom: 20px;
      line-height: 1.8;
    }

    .check-list {
      list-style: none;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      margin-top: 24px;
    }

    .check-list li {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-main);
    }

    .check-list li svg {
      width: 18px;
      height: 18px;
      fill: var(--secondary);
      flex-shrink: 0;
    }

    .overview-visual {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-xl);
      padding: 32px;
      box-shadow: var(--shadow-lg);
    }

    .model-tags-box {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 16px;
    }

    .model-tag {
      font-size: 12px;
      padding: 6px 12px;
      background: var(--bg-alt);
      border-radius: var(--radius-sm);
      color: var(--text-muted);
      font-weight: 500;
      border: 1px solid rgba(226, 232, 240, 0.8);
      transition: var(--transition);
    }

    .model-tag:hover {
      background: rgba(79, 70, 229, 0.08);
      color: var(--primary);
      border-color: rgba(79, 70, 229, 0.2);
    }

    /* Card Grid System */
    .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: 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(-4px);
      box-shadow: var(--shadow-lg);
      border-color: rgba(79, 70, 229, 0.25);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      border-radius: var(--radius-md);
      background: linear-gradient(135deg, rgba(79, 70, 229, 0.1) 0%, rgba(6, 182, 212, 0.1) 100%);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
    }

    .card-icon svg {
      width: 24px;
      height: 24px;
      fill: currentColor;
    }

    .feature-card h4 {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .feature-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      flex-grow: 1;
    }

    /* Process Steps */
    .process-timeline {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 16px;
      position: relative;
    }

    .step-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px 18px;
      text-align: center;
      position: relative;
      box-shadow: var(--shadow-sm);
    }

    .step-number {
      width: 36px;
      height: 36px;
      line-height: 36px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      font-weight: 700;
      font-size: 14px;
      margin: 0 auto 16px;
    }

    .step-item h5 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .step-item p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }

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

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

    .comparison-table th,
    .comparison-table td {
      padding: 18px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 14px;
    }

    .comparison-table th {
      background: var(--bg-alt);
      color: var(--text-main);
      font-weight: 700;
    }

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

    .comparison-table .highlight-col {
      background: rgba(79, 70, 229, 0.03);
      font-weight: 600;
      color: var(--primary);
    }

    .score-badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #fef3c7;
      color: #b45309;
      padding: 4px 10px;
      border-radius: 999px;
      font-size: 13px;
      font-weight: 700;
    }

    /* Media Visual Section */
    .visual-gallery {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 32px;
    }

    .visual-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .visual-media-box {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: var(--bg-alt);
      overflow: hidden;
    }

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

    .visual-media-box:hover img {
      transform: scale(1.03);
    }

    .visual-info {
      padding: 20px;
    }

    .visual-info h4 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .visual-info p {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* Testimonials */
    .testimonial-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-content {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 20px;
      position: relative;
    }

    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid var(--border-color);
      padding-top: 16px;
    }

    .user-avatar-circle {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: #ffffff;
      font-weight: 700;
      font-size: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }

    .user-meta h5 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.3;
    }

    .user-meta span {
      font-size: 12px;
      color: var(--text-light);
    }

    /* FAQ Section */
    .faq-wrapper {
      max-width: 880px;
      margin: 0 auto;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      margin-bottom: 14px;
      overflow: hidden;
      transition: var(--transition);
    }

    .faq-header {
      width: 100%;
      padding: 18px 24px;
      text-align: left;
      background: none;
      border: none;
      font-size: 16px;
      font-weight: 600;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

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

    .faq-icon {
      width: 20px;
      height: 20px;
      transition: transform 0.3s ease;
      flex-shrink: 0;
    }

    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }

    .faq-body {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: rgba(248, 250, 252, 0.5);
    }

    .faq-item.active .faq-body {
      max-height: 200px;
      padding: 0 24px 20px 24px;
    }

    .faq-body p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* Form Section */
    .form-layout {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 48px;
      align-items: start;
    }

    .form-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-xl);
      padding: 36px;
      box-shadow: var(--shadow-lg);
    }

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

    .form-label {
      display: block;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      font-size: 14px;
      color: var(--text-main);
      background: #ffffff;
      transition: var(--transition);
      outline: none;
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
    }

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

    .contact-card-sidebar {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-xl);
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }

    .contact-item-row {
      display: flex;
      align-items: flex-start;
      gap: 16px;
      margin-bottom: 24px;
    }

    .contact-qr-box {
      margin-top: 24px;
      padding: 20px;
      background: var(--bg-alt);
      border-radius: var(--radius-lg);
      text-align: center;
    }

    .contact-qr-box img {
      width: 140px;
      height: 140px;
      object-fit: contain;
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      background: #fff;
    }

    /* Articles and Links Section */
    .article-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 24px;
    }

    .article-tag-link {
      display: inline-flex;
      align-items: center;
      padding: 8px 16px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      color: var(--text-main);
      text-decoration: none;
      font-size: 14px;
      font-weight: 500;
      transition: var(--transition);
    }

    .article-tag-link:hover {
      border-color: var(--primary);
      color: var(--primary);
      box-shadow: var(--shadow-sm);
    }

    /* Footer */
    footer.site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 60px 0 32px 0;
      color: var(--text-muted);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 48px;
    }

    .footer-col h5 {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 18px;
    }

    .footer-links-list {
      list-style: none;
    }

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

    .footer-links-list a {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 14px;
      transition: var(--transition);
    }

    .footer-links-list a:hover {
      color: var(--primary);
    }

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

    .footer-friend-links a {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 13px;
      transition: var(--transition);
    }

    .footer-friend-links a:hover {
      color: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: var(--text-light);
    }

    /* Floating Customer Service */
    .floating-widget {
      position: fixed;
      right: 24px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .float-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: #ffffff;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-lg);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-main);
      cursor: pointer;
      text-decoration: none;
      transition: var(--transition);
      position: relative;
    }

    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    .float-btn svg {
      width: 22px;
      height: 22px;
      fill: currentColor;
    }

    .float-qr-popup {
      position: absolute;
      right: 64px;
      bottom: 0;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 12px;
      box-shadow: var(--shadow-xl);
      display: none;
      text-align: center;
      width: 140px;
    }

    .float-qr-popup img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-sm);
      display: block;
    }

    .float-qr-popup span {
      display: block;
      font-size: 12px;
      color: var(--text-muted);
      margin-top: 6px;
    }

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

    /* Responsive Design */
    @media (max-width: 1024px) {
      .hero-title { font-size: 38px; }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .process-timeline { grid-template-columns: repeat(3, 1fr); }
      .footer-grid { grid-template-columns: 1fr 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 24px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
      }
      .nav-links.active { display: flex; }
      .hero-title { font-size: 28px; }
      .hero-desc { font-size: 15px; }
      .overview-grid { grid-template-columns: 1fr; }
      .grid-3, .grid-4, .process-timeline, .visual-gallery { grid-template-columns: 1fr; }
      .form-layout { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; gap: 32px; }
      .check-list { grid-template-columns: 1fr; }
    }