/* PDFSun Global Theme Variables & Educational Ad Grid System */
:root {
  --bg-color: #ffffff;
  --text-color: #0f172a;
  --accent-color: #2563eb;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --border-color: #e2e8f0;
  --accent-hover: #1d4ed8;
}

.dark {
  --bg-color: #0f172a;
  --text-color: #f8fafc;
  --accent-color: #3b82f6;
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --border-color: #334155;
  --accent-hover: #60a5fa;
}

/* Responsive Ad Grid Layout */
.educational-ad-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .educational-ad-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Gently scale up and shift shadow on hover for engagement */
.educational-ad-grid > * {
  border-radius: 1rem !important;
  border: 1px solid #e2e8f0;
  transition: transform 350ms cubic-bezier(0.34, 1.56, 0.64, 1), 
              box-shadow 350ms cubic-bezier(0.16, 1, 0.3, 1), 
              border-color 350ms ease;
  will-change: transform, box-shadow;
}

.dark .educational-ad-grid > * {
  border-color: #334155;
}

.educational-ad-grid > *:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 22px 40px -10px rgba(0, 0, 0, 0.18), 0 10px 20px -5px rgba(245, 158, 11, 0.25);
  border-color: #fbbf24 !important;
}