/* CSS Variables & Global Styles - Royal Blue Bright */
    :root {
      --primary: #1d4ed8;
      --primary-hover: #1e40af;
      --primary-light: #eff6ff;
      --accent: #2563eb;
      --accent-bright: #3b82f6;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 2px 8px rgba(37, 99, 235, 0.05);
      --shadow-md: 0 8px 24px rgba(37, 99, 235, 0.08);
      --shadow-lg: 0 16px 32px rgba(29, 78, 216, 0.12);
      --radius: 12px;
      --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-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      background-color: var(--bg-main);
      color: var(--text-main);
      overflow-x: hidden;
    }

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

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

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

    /* Top Navigation Header */
    .header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    .brand-group {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .ai-page-logo {
      height: 40px;
      width: auto;
      object-fit: contain;
    }

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

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0; /* Strictly set as required */
    }

    .nav-links a {
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: 6px;
      white-space: nowrap;
    }

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

    .nav-cta {
      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: var(--transition);
      text-decoration: none;
      white-space: nowrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
    }

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

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

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

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

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

    .section-badge {
      display: inline-block;
      padding: 6px 14px;
      background-color: var(--primary-light);
      color: var(--primary);
      font-size: 0.85rem;
      font-weight: 700;
      border-radius: 20px;
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 16px;
    }

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

    /* Hero Section - STRICT: NO IMAGES inside Hero */
    .hero-section {
      padding: 100px 0 80px 0;
      background: linear-gradient(180deg, #eff6ff 0%, #f8fafc 100%);
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-glow {
      position: absolute;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(37,99,235,0.12) 0%, rgba(255,255,255,0) 70%);
      top: -100px;
      left: 50%;
      transform: translateX(-50%);
      pointer-events: none;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 900px;
      margin: 0 auto;
    }

    .hero-h1 {
      font-size: 2.5rem;
      font-weight: 900;
      color: var(--text-main);
      letter-spacing: -0.5px;
      margin-bottom: 20px;
      line-height: 1.25;
    }

    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-muted);
      margin-bottom: 36px;
      max-width: 780px;
      margin-left: auto;
      margin-right: auto;
    }

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

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 40px;
    }

    .stat-card {
      background: var(--bg-card);
      padding: 24px 16px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      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: 2rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
    }

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

    /* Card Grids */
    .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: 30px;
    }

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

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

    .feature-icon-badge {
      width: 48px;
      height: 48px;
      border-radius: 10px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.2rem;
      margin-bottom: 18px;
    }

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

    .feature-desc {
      font-size: 0.95rem;
      color: var(--text-muted);
      flex-grow: 1;
    }

    .model-tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 14px;
    }

    .model-tag {
      background: var(--bg-main);
      border: 1px solid var(--border-color);
      color: var(--primary);
      padding: 4px 10px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
    }

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

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

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

    .comparison-table th {
      background: var(--primary-light);
      color: var(--primary);
      font-weight: 700;
      font-size: 1rem;
    }

    .comparison-table tr:hover {
      background: #f1f5f9;
    }

    .badge-recommend {
      display: inline-block;
      background: #dbeafe;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 12px;
      font-weight: 700;
      font-size: 0.85rem;
    }

    /* Rating Highlight Box */
    .rating-box {
      background: linear-gradient(135deg, #1e40af 0%, #2563eb 100%);
      color: #ffffff;
      padding: 30px;
      border-radius: var(--radius);
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 30px;
      box-shadow: var(--shadow-md);
    }

    .rating-score {
      font-size: 3rem;
      font-weight: 900;
      line-height: 1;
    }

    .rating-stars {
      color: #f59e0b;
      font-size: 1.5rem;
      margin-top: 4px;
    }

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

    .step-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 20px;
      text-align: center;
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #fff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 12px auto;
    }

    /* Review Cards */
    .review-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
    }

    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
    }

    .avatar-placeholder {
      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;
    }

    .user-info .name {
      font-weight: 700;
      color: var(--text-main);
    }

    .user-info .role {
      font-size: 0.85rem;
      color: var(--text-light);
    }

    /* Case Media Showcase */
    .case-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .case-img-wrap {
      width: 100%;
      overflow: hidden;
      background: #e2e8f0;
    }

    .case-img-wrap img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      display: block;
      transition: var(--transition);
    }

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

    .case-content {
      padding: 20px;
    }

    /* FAQ Accordion */
    .faq-grid {
      display: flex;
      flex-direction: column;
      gap: 16px;
      max-width: 900px;
      margin: 0 auto;
    }

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

    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      font-size: 1.05rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      color: var(--text-main);
    }

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

    .faq-answer {
      padding: 0 24px 20px 24px;
      color: var(--text-muted);
      font-size: 0.95rem;
      display: none;
      border-top: 1px dashed var(--border-color);
      padding-top: 16px;
    }

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

    .faq-icon {
      font-weight: 400;
      font-size: 1.2rem;
      transition: transform 0.3s;
    }

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

    /* Contact Form Section */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      gap: 40px;
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-lg);
    }

    .contact-info {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .info-item {
      display: flex;
      align-items: flex-start;
      gap: 14px;
    }

    .info-icon {
      width: 40px;
      height: 40px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      flex-shrink: 0;
    }

    .qr-box {
      margin-top: 10px;
      width: 140px;
      padding: 8px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 8px;
    }

    .qr-box img {
      width: 100%;
      height: auto;
      display: block;
    }

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

    .form-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;
      transition: var(--transition);
      background: var(--bg-main);
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }

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

    /* Articles Link Section */
    .article-list {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

    .article-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      padding: 20px;
      border-radius: var(--radius);
      transition: var(--transition);
    }

    .article-card:hover {
      border-color: var(--accent-bright);
      box-shadow: var(--shadow-sm);
    }

    .article-card a {
      font-weight: 700;
      font-size: 1rem;
      color: var(--text-main);
    }

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

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

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

    .footer-brand h3 {
      color: #ffffff;
      font-size: 1.3rem;
      margin-bottom: 14px;
    }

    .footer-links h4,
    .footer-friends h4 {
      color: #ffffff;
      font-size: 1rem;
      margin-bottom: 16px;
    }

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

    .footer-links li {
      margin-bottom: 8px;
    }

    .footer-links a,
    .footer-friends a {
      color: #94a3b8;
      font-size: 0.9rem;
      text-decoration: none;
    }

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

    .footer-friends {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

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

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

    .float-btn {
      width: 50px;
      height: 50px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-lg);
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      font-weight: 700;
      font-size: 0.85rem;
    }

    .float-btn:hover {
      transform: scale(1.1);
      background: var(--primary-hover);
      color: #ffffff;
    }

    /* Responsive Design */
    @media (max-width: 992px) {
      .hero-h1 { font-size: 2rem; }
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .flow-steps { grid-template-columns: repeat(2, 1fr); }
      .contact-wrapper { grid-template-columns: 1fr; }
      .footer-content { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .nav-toggle { display: block; }
      .hero-stats { grid-template-columns: repeat(2, 1fr); }
      .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .flow-steps { grid-template-columns: 1fr; }
      .rating-box { flex-direction: column; text-align: center; gap: 16px; }
      .article-list { grid-template-columns: 1fr; }
      .footer-content { grid-template-columns: 1fr; }
    }