<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

        <style>

        .redtile {
            width: 50px;
            height: 50px;
            position: absolute;
            background-color: red;
        }

        </style>

    </head>
    <body>
        <div class="redtile" style="left: 0px; top: 0px;"></div>
    </body>
</html>