<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">
<div class="wrapper">
<div class="example-1">Example 1</div>
<div class="example-2">Example 2</div>
<div class="example-3">Example 3</div>
</div>
<div style="clear: both;"></div>
</div>
</div>
.wrapper
{
padding: 20px;
}
@keyframes shadow-pulse
{
0% {
box-shadow: 0 0 0 0px rgba(0, 0, 0, 0.2);
}
100% {
box-shadow: 0 0 0 35px rgba(0, 0, 0, 0);
}
}
@keyframes shadow-pulse-big
{
0% {
box-shadow: 0 0 0 0px rgba(0, 0, 0, 0.1);
}
100% {
box-shadow: 0 0 0 70px rgba(0, 0, 0, 0);
}
}
.example-1
{
float: left;
margin: 40px;
width: 130px;
height: 130px;
font: 13px/130px 'Barlow Semi Condensed', sans-serif;
text-transform: uppercase;
letter-spacing: 1px;
color: #fff;
text-align: center;
background: rgba(30, 144, 255, 0.6);
border-radius: 50%;
animation: shadow-pulse 1s infinite;
}
.example-2
{
float: left;
margin: 75px 40px 0 40px;
width: 130px;
height: 60px;
font: 13px/60px 'Barlow Semi Condensed', sans-serif;
text-transform: uppercase;
letter-spacing: 1px;
color: #fff;
text-align: center;
background: rgba(3, 3, 3, 0.6);
border-radius: 3px;
animation: shadow-pulse 1s 3;
}
.example-3
{
float: left;
margin: 40px 0 0 40px;
width: 130px;
height: 130px;
font: 13px/130px 'Barlow Semi Condensed', sans-serif;
text-transform: uppercase;
letter-spacing: 1px;
color: #fff;
text-align: center;
background: rgba(30, 144, 255, 0.6);
border-radius: 50%;
animation: shadow-pulse-big 1s 1;
}
Resources
