Hi All,

I am looking at blueprint styles, and there is font-size declared on html element (100.01%) and also on body (75%). Other text elements have their font size set using em's.
  • Why declare font size on html and body as well?
  • Why use percent on html/body and em's on others?

I thought I can just use font-size: 1em on body and go from there... using only em's, why is there need for % on body element, and also why is font-size used on html?
One more question about line height. Should it be declared as number withou em's, line-height: 1.5 ?