Just a question ...
Despite px being easier to understand, shouldn't we all be using ems when defining font-size? Which would mean that in the base css body should be defined as:
font-size:62.5%; /*Sets font size to 10 pixels = 1em. */
I am only posting this for discussion and viewpoints. Personally, I can use either but I was told that ems are better because of all the different screen sizes (computers, mobiles...).