<!DOCTYPE html> <title>flexbox | margins</title> <link rel="author" href="http://opera.com" title="Opera Software"> <link rel="help" href="http://www.w3.org/TR/css-flexbox-1/#flex-containers"> <link rel="match" href="flexbox_margin-ref.html"> <style> div { background: black; margin: 1em; height: 4em; display: flex; justify-content: space-around; } </style> <div></div>