- From: L. David Baron <dbaron@dbaron.org>
- Date: Fri, 2 Sep 2011 15:11:23 -0700
- To: www-style@w3.org
http://www.w3.org/TR/2011/WD-css3-conditional-20110901/ has been
published as the first public working draft of the CSS Conditional
Rules Module. To quote from its introduction:
CSS 2.1 defines one type of conditional group rule, the ‘@media’
rule, and allows only rulesets (not other @-rules) inside of it.
The ‘@media’ rule provides the ability to have media-specific
style sheets, which is also provided by style sheet linking
features such as ‘@import’ and <link>. The restrictions on the
contents of ‘@media’ rules made them less useful; they have
forced authors using CSS features involving @-rules in
media-specific style sheets to use separate style sheets for
each medium.
This specification extends the rules for the contents of
conditional group rules to allow other @-rules, which enables
authors to combine CSS features involving @-rules with media
specific style sheets within a single style sheet.
This specification also defines additional types of conditional
group rules, ‘@supports’ and ‘@document’, to address author and
user requirements.
The ‘@supports’ rule allows CSS to be conditioned on
implementation support for CSS properties and values. This rule
makes it much easier for authors to use new CSS features and
provide good fallback for implementations that do not support
those features. This is particularly important for CSS features
that provide new layout mechanisms, and for other cases where a
set of related styles needs to be conditioned on property
support.
The ‘@document’ rule allows CSS to be conditioned on the page to
which the style sheet is being applied. This allows users to
apply styles to a particular page or group of pages, which
greatly increases the power of user style sheets.
The CSS working group welcomes comments on this specification. The
preferred place for them is this mailing list, <www-style@w3.org>.
Please start the subject line of your message with
[css3-conditional], as I did in this message. (But please start a
new thread for each topic rather than responding to this one.)
Note these three different URLs for this specification:
http://www.w3.org/TR/2011/WD-css3-conditional-20110901/ is a
permanent archive of the version published yesterday as a W3C
technical report.
http://dev.w3.org/csswg/css3-conditional/ is the editor's draft,
which will be updated most promptly in response to feedback.
http://www.w3.org/TR/css3-conditional/ is the most recent version
published as a W3C technical report, which will be updated much less
frequently: when the working group wishes to solicit wider feedback
or advance this document on the W3C Recommendation track.
-David
--
𝄞 L. David Baron http://dbaron.org/ 𝄂
𝄢 Mozilla Corporation http://www.mozilla.com/ 𝄂
Received on Friday, 2 September 2011 22:11:55 UTC