[css-values] Can <resolution> values be negative?

[alancutter]

https://drafts.csswg.org/css-values/#resolution

The definition for the does not exclude negative values. It would be good to clarify this as intentional if it is.

[frivoal]

I don't think the definition of the unit should have anything to say about negative values. That should be handled in the definition of the properties (and descriptors) that accept resolution values.

[alancutter]

That sounds reasonable.