Hi All. I need some answers concerning the difference between pixels and ems. Is the preference for modern browsers to measure say, font-size in ems rather than pixels a universal rule? What would say, 2ems be equivalent too in pixels? Are ems just used in font or text sizes or can i use it to style other elements such as margins or borders? Better still, if i could be pointed to a good tutorial on this, I'll be very grateful. Cheers!