[css-logical] Explicitly define each logical property group

[Loirooriol]

The spec says

Each set of related flow-relative longhand properties and their parallel physical properties form a logical property group. For example, the padding-* properties form a single logical property group, the margin-* properties form a separate logical property group, etc.

The term "set of related properties" is ambiguous and the example is not clear enough. For example, I'm not sure if all border-* belong to the same logical property group, or if there are three different groups for border-*-width, border-*-style and border-*-color. I guess the latter suffices for #2924

To make it clear, in each relevant section I would explicitly list the logical property group, e.g. in https://drafts.csswg.org/css-logical/#margin-properties I would say

The properties margin-block-start, margin-block-end, margin-inline-start, margin-inline-end, margin-top, margin-bottom, margin-left, and margin-right form a logical property group.

[FremyCompany]

I assumed there would be three groups indeed. Serialization to super-shorthands like border remain an interesting problem, but probably doesn't require the concept of group as much.

[Loirooriol]

In #3030 (comment) @dbaron also said

border is also special because its longhands include three logical property groups, for border-color, border-style, and border-width.

[fantasai]

Made some clarifications. Note that only longhands can form a logical property group, shorthands don't. Lmk if this is clear enough.

[Loirooriol]

I think it would be clearer to explicitly define all logical property group, but I guess this avoids the confusion with borders.

csswg-drafts/css-logical-1/Overview.bs

Line 299 in e7dc18e

which set equivalent styles on different sides or dimensions of a box,

Nit: the border radius properties form a logical property group but they affect box corners, not box sides nor box dimensions.

[fantasai]

I think it would be clearer to explicitly define all logical property group

I think we should defer that aspect of this issue to #2822

Pushed a more complete rewrite of this section, btw. Hopefully it's better now.
https://drafts.csswg.org/css-logical-1/#box

Please close out this issue if you are satisfied, or complain at me if you are not. :)

[Loirooriol]

Logical Property Group: <identifier> from #2822 will satisfy me.

But note the nit remains, border radius properties affect box corners, not box sides nor box dimensions.

setting equivalent styles on the various sides or dimensions of a box