.heart {
  color: gray; /* default */
  font-size: 20px;
  cursor: pointer;
  transition: color 0.3s ease, transform 0.2s ease;
  background-color: transparent;
}

.heart.active {
  color: red; /* on click */
  transform: scale(1.2);
}



/* Pulse animation */
@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.4);
  }
  100% {
    transform: scale(1);
  }
}