Hi
I have a issue with the toolbar's image icon. I'm using a theme with firefox (white X) and in mac in the retina display the icon apears extremly big
this is due to a non scale independent image is used for the icon. In my secondary monitor (non-retina) there is no such issue because is a 1080 monitor.
Can you change the format of the icon to SVG? The SVG is scale independent so it doesn't matter where is used, the size will be always the same.