<!DOCTYPE html>
<html>
<head>
<style>
.ex1 {
width: 200px;
height: 100px;
padding: 10px;
border: 2px solid #00ab55;
box-sizing: border-box;
}
</style>
</head>
<body>
<h2>box-sizing: border-box</h2>
<div class="ex1">Webtutor</div>
</body>
</html>