<!DOCTYPE html>
<html>
	<head>
		<title>CSS level4 Selector :required and :optional</title>
		<link rel="author" title="LEE YUN HEE" href="mailto:zzirasi@gmail.com">

		<style>
			input {border:3px solid green;}
		</style>
	</head>
	<body>
		<p>
			You should see a green input box.
		</p>
        <p>
        	<input>
        </p>
        <p>
        	<input>
        </p>
	</body>
</html>