CSS3 Rounded corners are used to add special colored corner to body or text by using the border-radius property.
Example
<html>
<head>
<style>
#rcorner {
border-radius: 25px;
background: #8AC007;
padding: 20px;
width: 200px;
height: 150px;
}
</style>
</head>
<body>
<p id="rcorner">Rounded corners!</p>
</body>
</html>