<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<div class="yy"> </div>
</div>
</div>
.yy {
margin: 50px auto;
width: 250px;
height: 250px;
border-left: 1px solid #3ACFD5;
border-right: 1px solid #3a4ed5;
background-position: 0 0, 0 100% ;
background-repeat: no-repeat;
-webkit-background-size: 100% 1px;
-moz-background-size: 100% 1px;
background-size: 100% 1px;
background-image: -webkit-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%), -webkit-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%);
background-image: -moz-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%), -moz-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%);
background-image: -o-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%), -o-linear-gradient(left, #3acfd5 0%, #3a4ed5 100%);
background-image: linear-gradient(to right, #3acfd5 0%, #3a4ed5 100%), linear-gradient(to right, #3acfd5 0%, #3a4ed5 100%);
}
