Yep, that is exactly what I was looking for. Many thanks for that.
Last question in this context:
block and topic are vertically aligned with the text below them, but page is not, which is odd. Can vertical alignment be done for page, or is it a Logseq quirk?
which I had because text in “regular” tables was only centered in some columns.
When I disabled this snippet the page header was aligned again. I still find it odd that only the page header was out of kilter, but that is not important.
What counts is the solution, and you provided it.
Many thanks for your help and time!