Source Code: (back to article)
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
<style>
body {
background: transparent;
}
.vcenter {
display: inline-block;
vertical-align: middle;
float: none;
max-width: 49%;
}
.big-box {
height: 8em;
border: 1px solid purple;
background: red;
}
.small-box {
height: 2em;
border: 1px solid green;
background: green;
}
</style>
</head>
<body>
<div class="container">
<div class="row">
<div class="col-xs-6 vcenter">
<div class="big-box">Big</div>
</div>
<div class="col-xs-6 vcenter">
<div class="small-box">Small</div>
</div>