I can make Firefox not display the ugly dotted focus outlines on links with this:
a:focus {
outline: none
There's no way to remove these dotted focus in Firefox using CSS.
If you have access to the computers where your webapplication works, go to about:config in Firefox and set browser.display.focus_ring_width
to 0. Then Firefox won't show any dotted borders at all.
The following bug explains the topic: https://bugzilla.mozilla.org/show_bug.cgi?id=74225