.heart {
  background-color: crimson;
  display: inline-block;
  width: 100px;
  height: 100px;
  position: relative;
  top: 0;
  transform: rotate(-45deg);
  position: absolute;
  left: 45%; 
  top: 45%;
  animation: heartbeat 1.25s infinite;
}

.heart::before,
.heart::after {
  content: "";
  background-color: crimson;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  position: absolute;
  animation: pulsecolor 1.25s infinite;
}

.heart::before {
  top: -50px;
  left: 0;
}

.heart::after {
  top: 0;
  left: 50px;
}

@keyframes heartbeat {
	0% {
    transform: scale(1)
               rotate(-45deg);
	  }
	10% {
    transform: scale(1.25)
               rotate(-45deg);
    background-color: #EF395E;
	  }
  100% {
      transform: scale(1)
                 rotate(-45deg);
  }
}

@keyframes pulsecolor {
  10% {
  background-color: #EF395E;
  }
}