support vertical-align: center

[LMR-eitea]

vertical-align: middle is defined as:

• center the element on baseline
• push it up by 0.5ex

This (usually) translates to being centered on lowercase letters, making it look incredibly off-center in relation to the line itself.

vertical-align: center meanwhile is defined as actually centering an object within the line. It's unfortunately only supported in Firefox as of 2026-10-06, but it can be reasonably approximated with middle calc(.5cap - .5ex) when needed. (this will technically center the object on capital letters instead of the full line, but that's very close to equivalent, usually less than 0.1em off in normal text)

I've attached a very crude test file to show the differences: test.html