@layer utilities {
  .glass-card {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }
  .dark .glass-card {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(156, 163, 175, 0.5);
  border-radius: 9999px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(107, 114, 128, 0.8);
}

/* Pulse animation for active lesson */
@keyframes active-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.4);
  }
  50% {
    box-shadow: 0 0 0 8px rgba(59, 130, 246, 0);
  }
}

.lesson-active {
  animation: active-pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Print optimizations */
@media print {
  body {
    background: white !important;
    color: black !important;
  }
  .no-print {
    display: none !important;
  }
  .print-only {
    display: block !important;
  }
  .page-break {
    page-break-before: always;
  }
}