That is a valid point. Although I think that if you are modifying CSS then you either know exactly what you are doing, or disabling it altogether and replacing

That is a valid point. Although I think that if you are modifying CSS then you either know exactly what you are doing, or disabling it altogether and replacing it with your own stylesheet. I think that there is quite a lot of stuff that will break if you increase the font size too much. I'll play with it a little bit more, the ems might be a better solution after all.