<div class="btn">
  <a href="javascript:void(0)">Create</a>
</div>

body{
  background-color : #000000;
}
.btn{
  position:absolute;
  top:50%;
  left:50%;
  border-radius : 3em;
  padding:1.2em 1em;
  transform: translate(-50%,-50%);
  background-image: linear-gradient(90deg,#3e56a7,#04acff,#eaaaaa,#e11adc,#a0a00f,#3e56a7,#14accc);
  background-size:400%;
}
a{
  letter-spacing:.2em;
  font-weight:600;
  font-size: 1.5em;
  padding:.6em 1.6em;
  background-color:black;
  font-family: 'Raleway', sans-serif;
  text-transform: Uppercase;
  color:white;
  border-radius : 1.5em;
  text-align:center;
  text-decoration:none;
}
.btn:hover{
  animation: animate 3s ease-out infinite;
}
a:hover{
  text-shadow:0 0 .5em rgba(255,255,255,0.8);
}
@keyframes animate{
  0%{
    background-position : 0%;
    box-shadow: 0 0 .8em #04acff;
  }
  50%{
    background-position: 60%;
    box-shadow: 0 0 .8em #e11adc;
  }
  100%{
    background-position: 100%;
    box-shadow: 0 0 .8em #3e56a7;
  }
}