<div class="button">
<a class="btn" href="#">Наведи на меня курсор</a>
 </div>

.button {
  margin:50px auto;
  
}
.btn {
  text-decoration:none;
  background:red;
  padding:2%;
  color:#fff;
  position:relative;
  font-size:18px;
  border-radius:5px;
  font-family: Roboto, sans-serif;
  
}
.btn:hover {
  animation:hide .5s ease-in-out 0s infinite alternate both;
}
@keyframes hide {
  0% {
    top:0; box-shadow:-1px -1px 3px #000;
  }
  50% {
    top:-2px; box-shadow:1px 1px 3px #000;
  }
  100% {
    top:2px; box-shadow:3px 3px 15px #000;
  }
}