<!DOCTYPE html>
<html>
<head>
<style>
#grad1 {
    height: 150px;
    width: 150px;
    background: -webkit-radial-gradient(60% 55%, closest-side, red, yellow, black); /* Safari 5.1 to 6.0 */
    background: -o-radial-gradient(60% 55%, closest-side, red, yellow, black); /* For Opera 11.6 to 12.0 */
    background: -moz-radial-gradient(60% 55%, closest-side, red, yellow, black); /* For Firefox 3.6 to 15 */
    background: radial-gradient(closest-side at 60% 55%, red, yellow, black); /* Standard syntax (must be last) */
}

#grad2 {
    height: 150px;
    width: 150px;
    background: -webkit-radial-gradient(60% 55%, farthest-side, red, yellow, black); /* Safari 5.1 to 6.0 */
    background: -o-radial-gradient(60% 55%, farthest-side, red, yellow, black); /* For Opera 11.6 to 12.0 */
    background: -moz-radial-gradient(60% 55%, farthest-side, red, yellow, black); /* For Firefox 3.6 to 15 */
    background: radial-gradient(farthest-side at 60% 55%, red, yellow, black); /* Standard syntax (must be last) */
}

#grad3 {
    height: 150px;
    width: 150px;
    background: -webkit-radial-gradient(60% 55%, closest-corner, red, yellow, black); /* Safari 5.1 to 6.0 */
    background: -o-radial-gradient(60% 55%, closest-corner, red, yellow, black); /* For Opera 11.6 to 12.0 */
    background: -moz-radial-gradient(60% 55%, closest-corner, red, yellow, black); /* For Firefox 3.6 to 15 */
    background: radial-gradient(closest-corner at 60% 55%, red, yellow, black); /* Standard syntax (must be last) */
}

#grad4 {
    height: 150px;
    width: 150px;
    background: -webkit-radial-gradient(60% 55%, farthest-corner, red, yellow, black); /* Safari 5.1 to 6.0 */
    background: -o-radial-gradient(60% 55%, farthest-corner, red, yellow, black); /* For Opera 11.6 to 12.0 */
    background: -moz-radial-gradient(60% 55%, farthest-corner, red, yellow, black); /* For Firefox 3.6 to 15 */
    background: radial-gradient(farthest-corner at 60% 55%, red, yellow, black); /* Standard syntax (must be last) */
}
</style>
</head>
<body>

<h3>Radial Gradients - Use of different size keywords</h3>

<p><strong>closest-side:</strong></p>
<div id="grad1"></div>

<p><strong>farthest-side:</strong></p>
<div id="grad2"></div>

<p><strong>closest-corner:</strong></p>
<div id="grad3"></div>

<p><strong>farthest-corner (this is default):</strong></p>
<div id="grad4"></div>

<p><strong>Note:</strong> Internet Explorer 9 and earlier versions do not support gradients.</p>

</body>
</html>

Radial Gradients - Use of different size keywords

closest-side:

farthest-side:

closest-corner:

farthest-corner (this is default):

Note: Internet Explorer 9 and earlier versions do not support gradients.