I never knew about CSS extensions until yesterday, when I was researching how to portray the "Windows key" button. I stumbled upon the CSS to style text to appear as buttons here,
http://en.wikipedia.org/wiki/Windows_keyThe CSS sets each of "-moz-border-radius", "
-webkit-border-radius", and "border-radius" to "2px;" to address appearance in various browsers.
---Pam