Sent by Tim Rivera on 30 September 2002 19:07
> In terms of font size, ems and percentages act exactly the same.
> So the following two rules are exactly equivalent:
> p {font-size: 0.8em;}
> p {font-size: 80%;}
That does appear to be true in IE5.5 and M1.0, but not in Opera. However, if
I resize the text using IE5.5's preferences, 'em' and '%' or no longer
equivalent. Other interesting changes occur when changing the text
size/magnification in the various browsers. In Mozilla 1.0 at 75% Text Zoom,
the 'ex' value lines up with the other values.
http://www.timrivera.com/tests/fontsize.html
Tim