User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:100.0) Gecko/20100101 Firefox/100.0

Steps to reproduce:

On a Windows system, Inspect a text run that has font-family:System-UI

Actual results:

Inspector's Fonts tab indicates Segoe UI

Expected results:

Segoe UI Variable is a new system-installed font on Windows 11,
and is likely to be backported to Window 10 around time of Win 11 release.
It should be supported in System-UI system font...
perhaps in addition to existing Segoe UI, or
perhaps instead of Segoe UI, if language coverage is comparable.

Bonus points for supporting when user-installed on pre-Win11 (dependent on privacy/fingerprinting settings, of course). :)

Download link: https://aka.ms/SegoeUIVariable

Emilio, I saw you added support for system-ui, can you find the right component and owner?

I guess a bigger question is if there isn't a bunch of places in our own UI where we want to default Segoe UI Variable instead of normal Segoe UI, but that's another bug.

system-ui uses the menu system font, which comes from here.

So ultimately it comes from the OS. We could override it of course, I guess. I suppose it'd be reasonable to in that function replace Segoe UI by Segoe UI Variable, Segoe UI or such? That'd also cover other system fonts that the front-end uses.

Of course we could also special-case Segoe UI variable in Windows in the font code that queries system-ui families here but I'd prefer not having to do that.

So ultimately it comes from the OS.

Huh, okay, that seems like an argument to not change this, i.e. it seems Windows 11 claims the system font is Segoe UI, not Segoe UI Variant.

Might also be interesting to check Edge.

Emilio, what are your thoughts on how to proceed here? Do we need input from someone? Do we close as wontfix?

I'd check how Edge behaves, but otherwise yeah, WONTFIX if they use the same font-family as we do seems fine for now.

Would you happen to know if Edge shows the same behavior?

From the research I've done so far, looks like Segoe UI Variable is indeed the new system font used by Windows 11, but is still a work in progress to get it to all components. And it's filtering back into Windows 10 as well. That said, I've seen no Edge/Blink issues to change css system-ui (yet).
If you'd like to close WONTFIX for now, that's fine by me...can always reopen or file a new bug when that occurs. Or just leave open; either way is fine by me.

Would certainly be nice at some point, as it looks better on high DPI screens.
FWIW, I've also seen mention of Segoe UI Variable Static, which is apparently to get the new design on older systems which don't support font variations, but do support hidpi ??? Will be interesting to follow.

Thank you. Let's wontfix this for now.