<div class="box">
</div>
@keyframes bounce {
  from {
    transform: translateY(0px);
  }
  to {
    transform: translateY(-20px);
  }
}

.box {
  animation: bounce 300ms alternate infinite cubic-bezier(.2, .65, .6, 1);
}

.box {
  width: 75px;
  height: 75px;
  background: slateblue;
  padding: 8px;
  display: grid;
  place-content: center;
  color: white;
  text-align: center;
  border-radius: 50%;
}

External CSS

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External JavaScript

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