<!doctype html>
<html>
<body style="-webkit-writing-mode:vertical-lr">
<div style="width:100px; background-color:yellow"></div>
<div style="float:left;width:100px;height:100px;background-color:green; margin-top:10px;"></div>
<div style="float:right;width:100px;height:100px;background-color:green; margin-bottom:10px"></div>
<div style="clear:left; float:left;width:100px;height:100px;background-color:purple; margin-top:10px"></div>
<div style="clear:right; float:right;width:100px;height:100px;background-color:purple; margin-bottom:10px"></div>
</div>