Re: Proposal for Updating the @support Rule in CSS

Hello Izzaque

Would you be able to share your proposal on our GitHub issues so that it can be seen more widely?

But before that, I would encourage you to check out the proposed new @when and @else at-rules, which may already do what you want. https://www.w3.org/TR/css-conditional-5/#at-ruledef-else

Kind regards,
Josh

—
Josh Tumath (he/him)
Senior Software Engineer, WebCore Design System, Channels & Product Excellence
BBC Product Group

From: 488269508@qq.com <488269508@qq.com>
Date: Tuesday, 7 January 2025 at 05:16
To: www-style@w3.org <www-style@w3.org>
Subject: Proposal for Updating the @support Rule in CSS

External: Think before clicking
Dear W3C,
I am writing to you with a proposal regarding the @support rule in CSS.
As we all know, with the continuous improvement of CSS standards, the @support rule is in urgent need of an update. In the existing @support rule, it can only check whether a single statement is valid. I have a new design concept in mind.
I suggest a new structure like this:
@support(true) {
    /* Statements to be checked. If the check passes, they will be implemented. */
    @catch {
        /* Fallback version */
    }
}
This new design, if implemented, would bring more flexibility for front - end developers. It would enable us to handle style compatibility and progressive enhancement in a more effective way. We could better adapt to different browser environments and user experiences.
I hope that the W3C could consider this proposal and start relevant discussions within the community. Thank you very much for your attention to this matter.
Best regards,
izzaque