<!DOCTYPE html>
<style>
    .container {
        position: relative;
        height: 10px;
        width: 50px;
        background-color: red;
    }
    .left {
        position: absolute;
        left: 0;
        top: 0;
        font: 10px/1 Ahem;
        color: green;
    }
</style>
<body>
    You should see a green rectangle. You shouldn't see any red.
    <div class="container">
        <div class="left">
            XXXXX
        </div>
    </div>
</body>