<div>
    <div style="display: inline-block; height: 0; width: 50px;">
        <div style="width: 50px; height: 50px; background-color: green;"></div>
    </div>
    <div id="float" style="float: left; height: 50px; width: 50px; background-color: red;"></div>
</div>
<script>
    document.body.offsetTop;
    document.getElementById("float").style.display = "none";
</script>
