Obviously not a big deal, but this is something that has always pissed me of with the websites I make and I decided to find a solution.
In FireFox when you click a link it outlines it which isn’t a big deal, but it does it for image links (buttons) too which is kinda annoying (at least to me 
)
Anyway just adding this to the CSS file seemed to fix the problem for me.
a {
outline: none;
}