Has someone been messing with the forum code?

[bitchstewie]

In different browsers I not longer see a "Sign In" option at the top of the page and the colours and fonts looks slightly off too.

Chrome (and in Incognito tabs) and Safari are both doing it.

[AndrewGP]

Same here with Firefox.

[mw88]

Header and footer are missing on macOS Safari too

[CarCrazyDad]

Yup - Broken on Chrome and Mobile Chrome

No headers or footers and odd text

Don't you guys have a test environment?

[Matt Dell]

No change our side. We're looking into what the cause might be.

[jeremyc]

Seems to be fixed for me now.