<!DOCTYPE html>
<!-- Any copyright is dedicated to the Public Domain.
http://creativecommons.org/publicdomain/zero/1.0/ -->
<html>
<head>
<style>
.flexContainer {
display: flex;
flex-direction: column;
border: 2px dotted black;
height: 298px;
}
.multicol {
height: 100px;
width: 200px;
-moz-column-width: 20px;
-moz-column-fill: auto;
border: 4px solid orange;
}
</style>
</head>
<body>
<div class="multicol">
<div class="flexContainer">
</div>
</div>
</body>
</html>