<!DOCTYPE html> <html><head><title>flexbox | margin: auto in overflow</title> <link href="http://opera.com" rel="author" title="Opera Software"> <link href="http://www.w3.org/TR/css-flexbox-1/#auto-margins" rel="help"> <link href="reference/flexbox_margin-auto-overflow-2-ref.htm" rel="match"> <style> div { background: blue; margin: 1em 0; border: 1px solid black; height: 8em; width: 32em; position: relative; display: flex; } span { background: white; margin: 1em auto; width: 12em; display: inline-block; flex: 0 0 auto; } span+span { background: yellow; width: 30em; } </style> </head><body><div> <span>one</span> <span>two</span> </div> </body></html>