애니메이션

---

 

HTML

<div class="back"></div>
<div class="heart"></div>

 

 

CSS

* {
  margin: 0;
  padding: 0;
}
.back {
  position: fixed;
  width: 100%;
  height: 100%;
  background: #fff;
  animation: back 1s infinite;
}
.heart {
  position: absolute;
  top: 50%;
  left: 50%;
  background: red;
  width: 50px;
  height: 50px;
  transform: rotate(-45deg);
  animation: beat 1s infinite;
}
.heart::after {
  content: '';
  position: absolute;
  top: 0;
  left: 25px;
  background: red;
  width: 50px;
  height: 50px;
  border-radius: 50%;
}
.heart::before {
  content: '';
  position: absolute;
  top: -25px;
  left: 0px;
  background: red;
  width: 50px;
  height: 50px;
  border-radius: 50%;
}
@keyframes back {
  50% {background: #ffe6f2}
}
@keyframes beat {
  0% {
    transform: scale(1) rotate(-45deg)
  }
  50% {
    transform: scale(0.5) rotate(-45deg)
  }
}