<!DOCTYPE html>
<title>flexbox | flex formatting context :: float intrusion</title>
<link rel="author" href="http://opera.com" title="Opera Software">
<style>
* {margin: 0;}
body {width: 600px;}
#float {
background: #3366cc;
width: 25%;
float: left;
}
#flex {
background: #ffcc00;
padding: 2em 0;
width: 80%;
clear: both;
}
div div {
background: pink;
margin: 0 2em;
height: 4em;
display: inline-block;
}
</style>
<div id="float">damer</div>
<div id="flex">
<div>Yellow box should be below the blue box</div>
</div>