Hi somehow i don't understand the differing display behaviour of a special character used within the content property in Firefox. i've stripped down everything and created a pen:
http://codepen.io/rpkoller/pen/Fbgav
In its' basic form the three lines are way thinner than e.g. within Safari or Chrome. If i add font-weight: bold they get a little bit thicker but still thinner than within Safari/Chrome. What is causing that significant difference in thickness and size (it seems the glyph itself is also displayed bigger in Firefox) towards the other browsers? Any hint would be appreciated. Thanks Ralf