<!DOCTYPE html>
<title>flexbox | visibility: collapse and line wrapping</title>
<link rel="author" href="http://opera.com" title="Opera Software">
<style>
body {
	margin: 0;
	width: 602px;
}
div {
	background: #3366cc;
	border: 1px solid black;
}
div::after {
	content: "";
	clear: both;
	display: block;
}
p {
	background: #ffcc00;
	margin: 1em 0;
	width: 300px;
	float: left;
}
</style>

<div>
	<p>filler</p>
	<p>filler</p>
	<p>filler</p>
	<p>filler</p>
</div>