[css-contain-3] Make container-type:auto the initial value?

[andruud]

It's not clear if/when style queries are going to happen, and there was an intent to make size queries shippable without style queries.

Given that, is container-type:style the best initial value? We can't implement a property without support for its initial value, so in order to ship separately we'd need to pick some other non-standard initial value. We can also not pretend to support container-type:style, since that breaks @supports etc.

Maybe we can make auto the initial value, and specify that behaves like style? We'd still pretend to support auto I suppose, but at least authors would be able to do @supports(container-type: style). Also we'd be able to note in the spec that auto can behave like none if style queries are not supported.

[SebastianZ]

Duplicate of #7066?

Sebastian

[andruud]

Not quite, the proposed initial value auto would still effectively mean style if it's supported. This is just so that we can violate the spec somewhat gracefully while shipping things gradually.

But yes, if we revert on style-by-default (#7066), then we can close this as well.

[SebastianZ]

I mean, both issues are directly connected with each other. If style queries are completely deferred to a later spec. then style cannot be the default value. Though so far it seems like they might stay but be restricted to custom properties.

I didn't follow the discussion about why style is the default and not none. Choosing auto and internally resolving it to style or none depending on whether style queries are supported sounds reasonable to me, though.

Sebastian