Technical review: Document anchored container queries

[chrisdavidmills]

Description

Chrome 143 adds support for anchored container queries: see https://chromestatus.com/feature/5177580990496768. Also see https://developer.chrome.com/blog/anchored-container-queries for Chrome's blog post coverage.

This PR:

• Adds a guide to explain anchored container queries. Note that this is added underneath the CSS anchor positioning module page rather than containment, as that is where it is specced.
• Adds details of anchored container query syntax to the container-type and @container reference pages.
• Links to the guide and otherwise mentions the feature in appropriate places. (I may have missed some; let me know if you spot any other places where this should be mentioned).

Motivation

Additional details

Related issues and pull requests

[github-actions]

Preview URLs (7 pages)

• /en-US/docs/Web/CSS/Guides/Anchor_positioning/Anchored_container_queries
• /en-US/docs/Web/CSS/Guides/Anchor_positioning/Try_options_hiding
• /en-US/docs/Web/CSS/Guides/Anchor_positioning
• /en-US/docs/Web/CSS/Guides/Conditional_rules
• /en-US/docs/Web/CSS/Guides/Containment/Container_queries
• /en-US/docs/Web/CSS/Reference/At-rules/@container
• /en-US/docs/Web/CSS/Reference/Properties/container-type

Flaws (14)

Note! 5 documents 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/Guides/Conditional_rules
Title: CSS conditional rules
Flaw count: 1

• macros:
  • Macro cssxref produces link /en-US/docs/Web/CSS/at-rule which is a redirect

---

URL: /en-US/docs/Web/CSS/Reference/At-rules/@container
Title: @container
Flaw count: 13

• broken_links:
  • Link /en-US/docs/Web/CSS/block-contents doesn't resolve
  • Link /en-US/docs/Web/CSS/custom-ident is a redirect
  • Link /en-US/docs/Web/CSS/size-feature doesn't resolve
  • Link /en-US/docs/Web/CSS/scroll-state-feature doesn't resolve
  • Link /en-US/docs/Web/CSS/function-token doesn't resolve
  • and 8 more flaws omitted

External URLs (2)

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

• https://drafts.csswg.org/css-conditional-5/ (1 time) (Note! This may be a new URL 👀)

---

URL: /en-US/docs/Web/CSS/Reference/Properties/container-type
Title: container-type

• https://drafts.csswg.org/css-conditional-5/ (1 time) (Note! This may be a new URL 👀)

(comment last updated: 2026-03-10 16:11:36)

[pepelsbey]

Hey! Is it work in progress or is it ready for review? :)

[chrisdavidmills]

Hey! Is it work in progress or is it ready for review? :)

This is still waiting for a tech review. @una, do you have time to review this, or is there someone else we could get to look at it?

[github-actions]

This pull request has merge conflicts that must be resolved before it can be merged.

[hamishwillee]

@chrisdavidmills Happy to review this if @estelle doesn't have bandwidth, but not until next week.

[chrisdavidmills]

@chrisdavidmills Happy to review this if @estelle doesn't have bandwidth, but not until next week.

I was waiting to see if Google could find a tech reviewer for this PR, but I reckon we should just get on with the editorial review stage if no one steps up by next week. Happy for either of you to do it.