<!DOCTYPE html>
<title>flexbox | justify-content: space-around | single item</title>
<link rel="author" href="http://opera.com" title="Opera Software">
<style>
div {
	background: blue;
	margin: 1em 0;
	border: 1px solid black;
	height: 8em;
	width: 30em;
}
span {
	background: white;
	margin: 1em auto;
	width: 6em;
	max-width: 6em;
	height: 6em;
	display: block;
}
</style>

<div>
	<span>one</span>
</div>