In Firefox and Chromium, a hyperlink styled as mw-ui-button doesn't display the Agora focus indicator, a blue box-shadow.
You can see this on http://en.wikipedia.org/wiki/Special:UserLogin?useNew=1 if you tab through to [ Join Wikipedia ]. In Firefox you see no highlight; in Chromium, you see a default black outline. You can force better behavior if you add class mw-ui-input , but I think the focus highlight should be the default.
Note this particular hyperlink has CSS (for #mw-createaccount-join) that sets a thin white border-shadow to separate it from the background image; that has to be disabled or overridden when it has the focus.
Version: unspecified
Severity: normal