<link href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.0.0/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="col-md-12">
<div class="loader">
<div></div>
<div></div>
<div></div>
<div></div>
</div>
</div>
</div>
</div>
.loader{
position: relative;
width: 8em;
height: 8em;
margin: 20px auto;
overflow: hidden;
background: rgba(0, 0, 0, 0.35);
}
.loader > div {
position: absolute;
width: 8em;
height: 8em;
animation: alpha 2.25s linear infinite forwards;
background: rgba(231, 76, 60, 0.75);
}
.loader > div:nth-child(1) {
top: -50%;
left: -50%;
}
.loader > div:nth-child(2) {
top: -50%;
right: -50%;
}
.loader > div:nth-child(3) {
bottom: -50%;
right: -50%;
}
.loader > div:nth-child(4) {
bottom: -50%;
left: -50%;
}
@keyframes alpha {
0% {
-moz-transform: rotate(0);
-ms-transform: rotate(0);
-webkit-transform: rotate(0);
transform: rotate(0);
background: rgba(231, 76, 60, 0.75);
}
25% {
background: rgba(230, 126, 34, 0.75);
}
50% {
border-radius: 50%;
background: rgba(142, 68, 173, 0.75);
}
75% {
background: rgba(41, 128, 185, 0.75);
}
100% {
-moz-transform: rotate(360deg);
-ms-transform: rotate(360deg);
-webkit-transform: rotate(360deg);
transform: rotate(360deg);
background: rgba(231, 76, 60, 0.75);
}
}
