Combine the Bootstrap classes to layout for different size screens
Combine the Bootstrap class
The following code stacks the columns on mobile by making one full-width and the other half-width.
<!DOCTYPE HTML>
<html>
<head>
<link href="http://java2s.com/style/bootstrap.min.css" rel="stylesheet">
<style>div{background:#eee;border:1px solid #DDD;}</style>
</head><!-- w w w . j av a 2 s . co m-->
<body style='margin:20px;'>
<div class="row">
<div class="col-12 col-lg-8">8</div>
<div class="col-6 col-lg-4">4</div>
</div>
</body>
</html>