<!DOCTYPE html>
<html lang="en-US">
<head>
<style>
div{
width: 300px;
height: 100px;
padding: 25px;
text-align: center;
border: 1px solid #8c8c8c;
box-sizing: content-box;
}
</style>
</head>
<body>
<h1>CSS box-sizing property</h1>
<div>
My Container
</div>
<button onclick="myFunction()">Click Me</button>
<script>
var x = document.getElementsByTagName("div")[0];
function myFunction(){
x.style.boxSizing = "border-box";
}
</script>
<p><strong>Note</strong>: Click on the button to change the 'box-sizing' from content-box to border-box.</p> </body>
</html>