:root {
      --primary: #0284c7;
      --primary-dark: #0369a1;
      --primary-light: #e0f2fe;
      --accent: #f97316;
      --accent-light: #ffedd5;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --bg-alt: #f1f5f9;
      --border: #e2e8f0;
      --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);
      --radius: 12px;
      --radius-sm: 6px;
      --max-width: 1200px;
      --transition: all 0.25s ease-in-out;
    }

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

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

    body {
      line-height: 1.6;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
      overflow-x: hidden;
    }

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

    a:hover {
      color: var(--primary-dark);
    }

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .header-nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border);
      box-shadow: var(--shadow-sm);
    }

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

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

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

    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      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-muted);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
      display: inline-block;
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 0.95rem;
      font-weight: 600;
      padding: 10px 20px;
      border-radius: 8px;
      border: 1px solid transparent;
      cursor: pointer;
      transition: var(--transition);
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff !important;
      box-shadow: 0 2px 4px rgba(2, 132, 199, 0.2);
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 4px 8px rgba(2, 132, 199, 0.3);
    }

    .btn-accent {
      background-color: var(--accent);
      color: #ffffff !important;
    }

    .btn-accent:hover {
      background-color: #ea580c;
      transform: translateY(-1px);
    }

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

    .btn-outline:hover {
      background-color: var(--bg-alt);
      border-color: var(--text-muted);
    }

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

    /* Hero Section (No Images Allowed) */
    .hero-section {
      background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #f8fafc 100%);
      padding: 80px 0 60px;
      border-bottom: 1px solid var(--border);
      position: relative;
    }

    .hero-content {
      text-align: center;
      max-width: 860px;
      margin: 0 auto;
    }

    .hero-tag {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid #bae6fd;
      border-radius: 30px;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--primary-dark);
      margin-bottom: 20px;
      box-shadow: var(--shadow-sm);
    }

    .hero-title {
      font-size: 2.5rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

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

    .hero-subtitle {
      font-size: 1.15rem;
      color: var(--text-muted);
      margin-bottom: 36px;
      line-height: 1.6;
    }

    .hero-cta-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 40px;
      padding-top: 40px;
      border-top: 1px solid rgba(2, 132, 199, 0.15);
    }

    .stat-card {
      background: rgba(255, 255, 255, 0.85);
      border: 1px solid #e0f2fe;
      border-radius: var(--radius);
      padding: 20px 16px;
      box-shadow: var(--shadow-sm);
    }

    .stat-num {
      font-size: 1.75rem;
      font-weight: 800;
      color: var(--primary-dark);
      margin-bottom: 4px;
    }

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

    /* Sections General */
    .section-wrap {
      padding: 80px 0;
      border-bottom: 1px solid var(--border);
    }

    .section-wrap.alt-bg {
      background-color: var(--bg-card);
    }

    .section-header {
      text-align: center;
      max-width: 700px;
      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;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

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

    /* Models Cloud */
    .models-cloud-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-bottom: 40px;
    }

    .model-chip {
      background: var(--bg-card);
      border: 1px solid var(--border);
      padding: 8px 16px;
      border-radius: 30px;
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: var(--transition);
    }

    .model-chip:hover {
      border-color: var(--primary);
      background-color: var(--primary-light);
      transform: translateY(-2px);
    }

    /* Features Grid */
    .feature-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

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

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

    .feature-icon-box {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      font-size: 1.5rem;
      color: var(--primary-dark);
    }

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

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

    /* Visual Showcase */
    .media-showcase-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
      margin-top: 30px;
    }

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

    .media-box img {
      width: 100%;
      height: 260px;
      object-fit: cover;
      display: block;
      transition: var(--transition);
    }

    .media-box img:hover {
      transform: scale(1.02);
    }

    .media-box-content {
      padding: 16px 20px;
    }

    .media-box-title {
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .media-box-desc {
      font-size: 0.85rem;
      color: var(--text-muted);
    }

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

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

    .step-number {
      display: inline-block;
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #fff;
      font-weight: 700;
      border-radius: 50%;
      text-align: center;
      line-height: 36px;
      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);
    }

    /* Comparison Table */
    .comparison-card {
      background: var(--bg-card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-md);
      overflow-x: auto;
    }

    .rating-banner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #f0fdf4;
      border: 1px solid #bbf7d0;
      padding: 16px 24px;
      border-radius: 8px;
      margin-bottom: 24px;
      flex-wrap: wrap;
      gap: 16px;
    }

    .rating-score {
      font-size: 1.25rem;
      font-weight: 700;
      color: #166534;
      display: flex;
      align-items: center;
      gap: 8px;
    }

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

    .comparison-table th,
    .comparison-table td {
      padding: 16px;
      border-bottom: 1px solid var(--border);
      font-size: 0.95rem;
    }

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

    .comparison-table tr:hover td {
      background: var(--bg-page);
    }

    .highlight-cell {
      color: var(--primary-dark);
      font-weight: 700;
      background: #f0f9ff;
    }

    /* Testimonials */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

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

    .testimonial-content {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 20px;
      font-style: italic;
    }

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

    .author-avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.1rem;
    }

    .author-meta h5 {
      font-size: 1rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .author-meta span {
      font-size: 0.85rem;
      color: var(--text-light);
    }

    /* FAQ Accordion */
    .faq-container {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 18px 24px;
      font-size: 1.05rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      color: var(--text-main);
      transition: var(--transition);
      user-select: none;
    }

    .faq-question:hover {
      background: var(--bg-alt);
      color: var(--primary);
    }

    .faq-icon {
      font-size: 1.25rem;
      transition: transform 0.2s ease;
      color: var(--text-light);
    }

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

    .faq-answer {
      display: none;
      padding: 0 24px 20px;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      border-top: 1px solid var(--bg-alt);
      margin-top: -4px;
      padding-top: 16px;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* Form Section */
    .form-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      background: var(--bg-card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }

    .form-info h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .form-info p {
      font-size: 0.95rem;
      color: var(--text-muted);
      margin-bottom: 24px;
    }

    .contact-card-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .contact-card-item {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .form-control-group {
      margin-bottom: 16px;
    }

    .form-label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .form-input,
    .form-select,
    .form-textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      color: var(--text-main);
      background-color: var(--bg-page);
      outline: none;
      transition: var(--transition);
      font-family: inherit;
    }

    .form-input:focus,
    .form-select:focus,
    .form-textarea:focus {
      border-color: var(--primary);
      background-color: #fff;
      box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
    }

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

    /* Articles & Links */
    .article-link-list {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 16px;
      margin-top: 20px;
    }

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

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

    /* Footer */
    .site-footer {
      background-color: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      margin-top: auto;
      border-top: 1px solid #1e293b;
    }

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

    .footer-col h4 {
      color: #f8fafc;
      font-size: 1.1rem;
      font-weight: 600;
      margin-bottom: 20px;
    }

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

    .footer-links-list a {
      color: #94a3b8;
      font-size: 0.9rem;
    }

    .footer-links-list a:hover {
      color: #38bdf8;
    }

    .qr-container {
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      gap: 8px;
    }

    .qr-container img {
      width: 110px;
      height: 110px;
      border-radius: 6px;
      background: #fff;
      padding: 4px;
    }

    .friend-links-box {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      margin-bottom: 24px;
    }

    .friend-links-box span {
      color: #f8fafc;
      font-weight: 600;
      margin-right: 12px;
      font-size: 0.9rem;
    }

    .friend-links-container {
      display: inline-flex;
      flex-wrap: wrap;
      gap: 16px;
      vertical-align: middle;
    }

    .friend-links-container a {
      color: #94a3b8;
      font-size: 0.9rem;
    }

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

    .footer-bottom {
      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;
    }

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

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

    /* Responsive Design */
    @media (max-width: 992px) {
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .process-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .form-layout {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .mobile-menu-toggle {
        display: block;
      }
      .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);
        box-shadow: var(--shadow-md);
      }
      .nav-links.show {
        display: flex;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links li a {
        display: block;
        padding: 10px 16px;
      }
      .hero-title {
        font-size: 1.85rem;
      }
      .media-showcase-grid {
        grid-template-columns: 1fr;
      }
      .process-steps {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }