<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<a class="button" href="#" title="Yes, turtles.">I like turtles!</a>
</div>
</div>
a.button{
display:inline-block;
text-decoration:none;
color:rgba(28, 190, 131, 1);
brackground-color:transparent;
border:1px solid rgba(28, 190, 131, 1);
border-radius:100px;
padding: .3em 1.2em;
margin:5px;
background-size: 200% 100%;
background-image: linear-gradient(to right, transparent 50%, rgba(28, 190, 131, 1) 50%);
transition: background-position .3s cubic-bezier(0.19, 1, 0.22, 1) .1s, color .5s ease 0s, background-color .5s ease;
}
a.button:hover{
color:rgba(255, 255, 255, 1);
background-color:rgba(28, 190, 131, 1);
background-position: -100% 100%;
}
