<html>
    <head>
        <style type="text/css">
            .c1 { color: red; }
            .c2 { background: blue; }
            #i1 { color: green; }
        </style>
    </head>
    <body>
        <div>
            <div id='i1'>Hello</div>
            <div class='c1'>World</div>
            <div class='c2'>Hello</div>
            <div class='c1 c2'>World</div>
        </div>
    </body>
</html>
