:root {
      --primary: #0284c7;
      --primary-dark: #0369a1;
      --primary-light: #e0f2fe;
      --secondary: #6366f1;
      --accent: #0ea5e9;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-surface: #ffffff;
      --bg-subtle: #f1f5f9;
      --border-color: #e2e8f0;
      --border-focus: #38bdf8;
      --shadow-sm: 0 1px 2px 0 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);
      --shadow-hover: 0 20px 25px -5px rgba(2, 132, 199, 0.12), 0 8px 10px -6px rgba(2, 132, 199, 0.08);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --radius-full: 9999px;
      --container-width: 1200px;
      --transition-fast: 0.2s ease;
      --transition-normal: 0.3s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html {
      font-size: 16px;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

    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;
      overflow-x: hidden;
    }

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

    ul, ol {
      list-style: none;
    }

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

    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      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-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .brand-area img.ai-page-logo {
      height: 40px;
      width: auto;
      object-fit: contain;
      display: block;
    }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
    }

    .nav-container {
      display: flex;
      align-items: center;
      gap: 24px;
    }

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

    .nav-links li a {
      font-size: 0.9375rem;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 0.9375rem;
      font-weight: 600;
      padding: 10px 20px;
      border-radius: var(--radius-full);
      border: 1px solid transparent;
      cursor: pointer;
      transition: all var(--transition-normal);
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.3);
    }

    .btn-primary:hover {
      box-shadow: 0 6px 18px rgba(2, 132, 199, 0.45);
      transform: translateY(-2px);
    }

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

    .btn-outline:hover {
      background: var(--primary-light);
      transform: translateY(-2px);
    }

    .btn-lg {
      padding: 14px 32px;
      font-size: 1.0625rem;
    }

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

    /* Hero Section */
    .hero-section {
      position: relative;
      background: linear-gradient(180deg, #f0f9ff 0%, #e0f2fe 50%, var(--bg-page) 100%);
      padding: 80px 0 60px;
      text-align: center;
      overflow: hidden;
    }

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

    .hero-title {
      font-size: 2.75rem;
      line-height: 1.25;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -1px;
    }

    .hero-desc {
      font-size: 1.125rem;
      color: var(--text-muted);
      max-width: 760px;
      margin: 0 auto 36px;
      line-height: 1.7;
    }

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

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 960px;
      margin: 0 auto;
    }

    .stat-card {
      background: #ffffff;
      padding: 24px 16px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition-normal);
    }

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

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

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

    /* Section Styles */
    .section-block {
      padding: 80px 0;
      border-bottom: 1px solid var(--border-color);
    }

    .section-block:nth-child(even) {
      background: #ffffff;
    }

    .section-header {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 50px;
    }

    .section-subtitle {
      font-size: 0.875rem;
      font-weight: 700;
      color: var(--primary);
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: 8px;
      display: inline-block;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }

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

    /* Platform Grid */
    .platform-tag-container {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-bottom: 30px;
    }

    .model-chip {
      background: var(--bg-subtle);
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: var(--radius-full);
      font-size: 0.875rem;
      font-weight: 500;
      color: var(--text-main);
      transition: all var(--transition-fast);
    }

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

    /* Feature Grid */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-normal);
      display: flex;
      flex-direction: column;
    }

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

    .feature-icon-box {
      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: 1.25rem;
      font-weight: 700;
      margin-bottom: 20px;
    }

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

    .feature-text {
      font-size: 0.9375rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* Steps */
    .steps-grid {
      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: var(--radius-md);
      padding: 24px;
      position: relative;
    }

    .step-index {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .step-title {
      font-size: 1.125rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

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

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

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

    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.9375rem;
    }

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

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

    .compare-table .highlight-col {
      background: #f0f9ff;
      font-weight: 600;
      color: var(--primary);
    }

    .score-badge {
      display: inline-block;
      background: #fef3c7;
      color: #b45309;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: var(--radius-full);
      font-size: 0.875rem;
    }

    /* Media Banner Showcase */
    .banner-showcase-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      margin-top: 30px;
    }

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

    .media-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      display: block;
    }

    .media-info {
      padding: 16px;
    }

    .media-title {
      font-size: 1rem;
      font-weight: 600;
      margin-bottom: 6px;
    }

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

    /* Testimonials */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

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

    .review-content {
      font-size: 0.9375rem;
      color: var(--text-muted);
      margin-bottom: 20px;
      line-height: 1.6;
    }

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

    .author-avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.125rem;
    }

    .author-name {
      font-size: 0.9375rem;
      font-weight: 600;
      color: var(--text-main);
    }

    .author-role {
      font-size: 0.8125rem;
      color: var(--text-light);
    }

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

    .faq-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: border-color var(--transition-fast);
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      font-size: 1.0625rem;
      font-weight: 600;
      color: var(--text-main);
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .faq-question::after {
      content: "+";
      font-size: 1.25rem;
      font-weight: 400;
      color: var(--primary);
      transition: transform var(--transition-fast);
    }

    .faq-item.active .faq-question::after {
      content: "-";
    }

    .faq-answer {
      display: none;
      padding: 0 24px 20px;
      font-size: 0.9375rem;
      color: var(--text-muted);
      line-height: 1.6;
      border-top: 1px solid var(--border-color);
      background: #fafafa;
    }

    .faq-item.active .faq-answer {
      display: block;
      padding-top: 16px;
    }

    /* Form Section */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: start;
    }

    .contact-info-box {
      background: var(--bg-surface);
      padding: 32px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
    }

    .contact-item {
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 20px;
    }

    .contact-label {
      font-size: 0.875rem;
      color: var(--text-light);
    }

    .contact-val {
      font-size: 1rem;
      font-weight: 600;
      color: var(--text-main);
    }

    .form-container {
      background: var(--bg-surface);
      padding: 36px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    .form-label {
      display: block;
      font-size: 0.875rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      font-size: 0.9375rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      background: #ffffff;
      color: var(--text-main);
      outline: none;
      transition: border-color var(--transition-fast);
    }

    .form-control:focus {
      border-color: var(--border-focus);
      box-shadow: 0 0 0 3px var(--primary-light);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    /* Articles & Links */
    .articles-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
      gap: 16px;
      margin-bottom: 30px;
    }

    .article-item {
      background: var(--bg-surface);
      padding: 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      transition: all var(--transition-fast);
    }

    .article-item:hover {
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    .article-item a {
      font-size: 0.9375rem;
      font-weight: 500;
      color: var(--text-main);
      display: block;
    }

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

    .friend-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      padding-top: 16px;
      border-top: 1px solid var(--border-color);
    }

    .friend-links a {
      font-size: 0.875rem;
      color: var(--text-muted);
      background: var(--bg-subtle);
      padding: 6px 12px;
      border-radius: var(--radius-sm);
    }

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

    /* Footer */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 40px 0 24px;
      border-top: 1px solid #1e293b;
    }

    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
      margin-bottom: 24px;
    }

    .footer-brand {
      color: #ffffff;
      font-size: 1.125rem;
      font-weight: 700;
    }

    .footer-nav {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .footer-nav a {
      color: #94a3b8;
      font-size: 0.875rem;
    }

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

    .footer-bottom {
      text-align: center;
      font-size: 0.8125rem;
      padding-top: 20px;
      border-top: 1px solid #1e293b;
    }

    /* Floating Widget */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }

    .kefu-trigger {
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: #ffffff;
      padding: 12px 18px;
      border-radius: var(--radius-full);
      box-shadow: var(--shadow-lg);
      font-weight: 600;
      font-size: 0.875rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      border: none;
    }

    .kefu-popover {
      display: none;
      background: #ffffff;
      padding: 16px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      text-align: center;
      width: 180px;
    }

    .kefu-popover img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-sm);
      margin-bottom: 8px;
    }

    .kefu-popover p {
      font-size: 0.75rem;
      color: var(--text-muted);
    }

    .floating-kefu:hover .kefu-popover {
      display: block;
    }

    /* Responsive */
    @media (max-width: 992px) {
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .banner-showcase-grid {
        grid-template-columns: repeat(1, 1fr);
      }
      .reviews-grid {
        grid-template-columns: repeat(1, 1fr);
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-menu-btn {
        display: block;
      }
      .hero-title {
        font-size: 2rem;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .steps-grid {
        grid-template-columns: 1fr;
      }
      .hero-stats-grid {
        grid-template-columns: 1fr;
      }
    }