Fx only. I have never seen an 'unsecure' popup and can't style it. If you come across one, post the search results page url and i will style that too. TIA!
It looks good with my (unpublished, tired of the site updates!) google style but you're welcome to fiddle with font to adjust to whatever goog style you might be using. If you need help with that, start a discussion and i will help (no rating needed in this case).