Description

Container Queries — size queries plus container query units, from CSS Containment 3. (Not including style queries.)

Container Queries were proposed for Interop 2022, but we did not have consensus for its inclusion. Instead, we added Containment as a focus area. For 2023, it might make sense to combine Containment (level 2) and Container Queries (level 3) into one area. Or perhaps create a new area alongside the previous one.

Rationale

Container Queries (size queries) has been one of the most requested features from web designers and developers for many years.

Ensuring Container Queries is fully interoperable would definitely help developers writing CSS and users going to websites that use Container Queries.

Specification

CSS Containment Module Level 3

Tests

Presumably an appropriate set of tests selected from:
https://wpt.fyi/results/css/css-contain/container-queries?label=experimental&label=master&aligned