CODE EXAMPLE FOR CSS

css animation box shadow

<div class="box">Box</div>
<style>
.box {
    width: 300px;
    padding: 40px 0;
    font: bold 46px sans-serif;
	text-align: center;
    background: #ccc;
    border: 1px solid #999;
    -webkit-animation: test 4s infinite; /* Chrome, Safari, Opera */
    animation: test 4s infinite;
}
/* Chrome, Safari, Opera */
@-webkit-keyframes test {
    50% {box-shadow: 8px 8px 16px #999;}
}
/* Standard syntax */
@keyframes test {
    50% {box-shadow: 8px 8px 16px #999;}
}
</style>