<!DOCTYPE html>

<html>
<head>
    <style>
        #indicator {
            position: absolute;
            top: 20px;
            left: 20px;
            width: 200px;
            height: 200px;
            background-color: green;
        }
    </style>
</head>
<body>

<div id="indicator"></div>
</body>
</html>