<!DOCTYPE html>
<html>
<head>
<style type="text/css">
body { font-size: 1600000px; }
body * { font-size: 10em; }
</style>
</head>
<body>
<div>
<div style="margin-top: 1em; margin-bottom: 1em;">A</div>
</div>
<div>
<div style="margin-top: 1em; margin-bottom: 1em;">B<div style="display: list-item; padding-left: 3px; float: left;"></div></div>
</div>
<div style="float: left;"></div>
</body>
</html>