On my 2013 Moto X running Android 4.4 and Firefox, I tried to log in to Phabricator. I clicked Phabricator's [Login or Register MediaWiki] button, and after logging into mediawiki.org the OAuth page appeared with the
Hi SPage (WMF),
would like to have basic access...
Privacy Cancel [Allow]
dialog on top of a grayed out window.
But, this dialog was positioned way off to the right and some way down the page. I couldn't see it at all until I zoomed out and scrolled:
I repeated the Phabricator login in Chrome and had the same problem: