<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <style type="text/css"> .multicol { margin: 1em; border: solid silver; width: 300px; -moz-column-width: 100px; -moz-column-gap: 0; height: 100px; } .float { float: right; width: 15px; background: aqua; height: 250px; } .L { float: left; } .container { width: 100%; background: red; } .clear { clear: left; border-bottom: solid orange; background: red; } </style> <p>The orange line should be halfway down the third column (immediately after the end of the aqua lines). <div class="multicol"> <div class="container"> <div class="float L"></div> <div class="float R"></div> </div> <div class="clear"></div> </div>