Well that's just naughty hahaha
Easier how? Now you have two places to edit your CSS.
Interesting, but too many browsers do a poor job of scaling.
Have a live example of this technique?
Haha I've got one btw. I used something like this in the www.brut-magazin.de menu (press space to open). It just uses transform:scale on the whole menu at different screen sizes because it is too complex to rebuilf it for every screensize.