<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en-US"> <head> <title>reftest, bug 424236</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"> body { font-size: 16px; } * { -moz-outline-offset: -1px; outline-offset: -1px; } body > span { outline: 1px dotted black; } /* can't compare to border combined with negative margin because of margin collapsing */ body > div { display: block; outline: 1px dotted black; width: 10em; } body > div + span + div { width: 5em; } </style> </head> <body> <span></span><div>text</div><span>Some words that must be wider than 10em</span><div>text</div> </body> </html>