After investigating this, it very much looks like the WikiHiero extension is assuming Vector in the print styles its using. It shouldn't do this. This is not a bug with Minerva. The Minerva styles work for the majority of tables.

I suggest the addition of the following rule:

.mw-hiero-table {     margin: 0;  }

I'm not sure if this is in the scope of the reading web team as we don't maintain this extension but fix looks straightforward.

Change 406849 had a related patch set uploaded (by Jdlrobson; owner: Jdlrobson):
[mediawiki/extensions/wikihiero@master] Fix display in Minerva skin with explicit margins

https://gerrit.wikimedia.org/r/406849

Tested the current patch (for review):

current result	result with patch	expected result

not perfect, but better

Change 428868 had a related patch set uploaded (by Krinkle; owner: Krinkle):
[mediawiki/skins/MinervaNeue@master] Change strategy for undoing '.content table' overrides

https://gerrit.wikimedia.org/r/428868

Change 428868 merged by jenkins-bot:
[mediawiki/skins/MinervaNeue@master] Change strategy for undoing '.content table' overrides

https://gerrit.wikimedia.org/r/428868

Change 406849 abandoned by Jdlrobson:
Fix display in Minerva skin with explicit margins

Reason:
I think the problem here is that hiero is outputting tables for an image. I'm not sure what design decisions led to that, but I think they should be revisited. I don't think Minerva should be expected to patch such a usage.

https://gerrit.wikimedia.org/r/406849

Now the same conflicts also with Vector. Everything is aligned left

@Dvorapa That is because of ChangeId I92acda377f4eaf7238888bb2fe2703b2f8aa5646 of T202359: [Regression pre-wmf.18] Toolbar does not get activated after pressing return and related T210695: Hieroglyphs are no longer inline

Translation, the extensions sucks and needs major work...

In T184221#4894181, @TheDJ wrote:

@Dvorapa That is because of ChangeId I92acda377f4eaf7238888bb2fe2703b2f8aa5646 of T202359: [Regression pre-wmf.18] Toolbar does not get activated after pressing return and related T210695: Hieroglyphs are no longer inline

Translation, the extensions sucks and needs major work...

Okay. I noticed it also has issues with some syntax, like missing hiero letter rotation (markup: A1\r ) or hidden cartouche ending (markup: 0> ), etc.