<!DOCTYPE html>
<p>Below there should be a blue square above a cyan square.</p>
<div style="columns:2; column-gap:0; width:100px; background:cyan;">
<div style="break-after:column; height:100px; background:blue;"></div>
<div style="float:left; width:100%; height:100px; background:blue;"></div>
<div style="height:200px;"></div>
</div>