Some time ago I came across an article by Jonathan Snook titled Font sizing with rem. Not so long story short;
In the early days of the web, we used pixels to size our text. It’s reliable and consistent. […] To get around that1, we can use em units. […] The problem with em-based font sizing is that the font size compounds. […] CSS3 introduces […] the
remunit, which stands for “root em”. […] Theremunit is relative to the root — or the html — element. That means that we can define a single font size on the html element and define allremunits to be a percentage of that…
A pretty sweet solution, regardless of not ever having any significant issues with the em compounding dilemma, none that I can reliably recall anyway. And I’ve used it on a few projects since reading it. It is a very tidy solution to what could potentially become quite a messy problem. For organizational’s sake, at the very least, I’m really quite fond of this solution. Read “An issue using rem” in its entirety