<!DOCTYPE html>
<html>
<head>
    <title>Reference File</title>
    <link rel="author" title="CJ Gammon" href="mailto:youremail@address.com">
    <style type="text/css">

        #container{
            position: relative;
        }

        .square{
            position: absolute;
        }

        #green{
            top: 50px;
            left: 50px;
            width: 100px;
            height: 100px;
            background: green;
        }

    </style>
</head>
<body>
    <p>The test passes if there is a green square and no red or blue square.</p>

    <div id="container">
        <div id="green" class="square"></div>
    </div>

</body>
</html>