More controlled degrading, @supported at-rule

In the past, CSS has relied on properties degrading gracefully in older 
browser which didn't support certain features, and this has worked 
remarkably well. However, when you start combining multiple properties 
to do complex layout, or use some of the advanced features of CSS3 such 
as opacity and columns, it may be that CSS does not degrade nearly so 
gracefully. I would like to propose an simple extension to CSS that 
allows CSS authors to detect UA support for properties and property values:

http://www.saintpatrickdc.org/bsmedberg/css-supported.html

Critique me, please, and also suggest whether this should be part of any 
CSS spec (even perhaps the core CSS3 syntax spec?).

I have done basic testing, and this rule seems to degrade gracefully (be 
completely ignored) in IE and Gecko-based browsers.

--BDS

Received on Thursday, 16 September 2004 21:20:45 UTC