[css-align-3] Consider making vertical centering

[brend8c]

I want to suggest vertical centering of blocks.
It's much easier to do. For instance:
"margin: auto 0", "margin: auto auto"
Without using flex elements.

[tabatkins]

While implementations have not yet caught up with the spec, it is defined that align-content: center should work on block containers, vertically centering their contents: https://drafts.csswg.org/css-align/#distribution-block

(We're hoping that this is still possible, and we don't have a bunch of existing web content accidentally relying on the property doing nothing for blocks.)

However, align-self: center is not possible in block containers, for the same reason Flexbox doesn't allow justify-self to work - there are multiple elements in the axis, and it's not clear how to reconcile each one asking for a particular alignment. *-content works because it aligns all the children as a group.

[brend8c]

Yes you tell right.
We know about margin: 0 auto; for horizontal centering.
But it would be logical if margin: auto 0 or margin: auto; work for vertical centering.
I'm talking about margin in order to expand its capabilities.

[tabatkins]

Ah, unfortunately that can't happen. Vertical auto margins have never affected positioning, for the reason I said earlier - there are multiple elements in the vertical axis, so it's not clear how multiple children with auto vertical margins should work.