FF149 @container style() allows but ignores !important

[hamishwillee]

This updated does two things.

1. Updates the "Using container size and style queries" doc to:
   • Update legacy note that only style queries with custom properties are supported. I believe all the types are - certainly that is what the @container docs indicate and the BCD seems to show.
   • Link the Container style queries intro to the more detailed section on @container doc.
2. Adds a note in @container docs that !important is allowed in style queries but ignored. This apparently is not clear in the spec but is in a WPT test that is passed by all browsers. This came up in https://bugzilla.mozilla.org/show_bug.cgi?id=2014095 and I think is worthy of a mention.

Related docs work can be tracked in in #43216

[github-actions]

Preview URLs (2 pages)

• /en-US/docs/Web/CSS/Guides/Containment/Container_size_and_style_queries
• /en-US/docs/Web/CSS/Reference/At-rules/@container

Flaws (12)

Note! 1 document with no flaws that don't need to be listed. 🎉

Found an unexpected or unresolvable flaw? Please report it here.

URL: /en-US/docs/Web/CSS/Reference/At-rules/@container
Title: @container
Flaw count: 12

• broken_links:
  • Link /en-US/docs/Web/CSS/Reference/Values/block-contents doesn't resolve
  • Link /en-US/docs/Web/CSS/Reference/Values/size-feature doesn't resolve
  • Link /en-US/docs/Web/CSS/Reference/Values/scroll-state-feature doesn't resolve
  • Link /en-US/docs/Web/CSS/Reference/Values/function-token doesn't resolve
  • Link /en-US/docs/Web/CSS/Reference/Values/any-value doesn't resolve
  • and 7 more flaws omitted

(comment last updated: 2026-03-20 00:21:28)

[dipikabh]

The updates makes sense, thanks!
This was a related relnote: https://github.com/mdn/content/pull/43473/changes