@keyframes beat {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.4);
  }
  100% {
    transform: scale(1);
  }
}
#heart {
  user-select: none;
  position: relative;
  margin: auto;
  display: flex;
  height: 192px;
  width: 192px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  position: relative;
  text-align: center;
  font-size: 4rem;
}
.beat {
  animation: beat 0.2s linear forwards;
}