How is it feeling? You should be able to have different padding values for all 4 sides and so long as there aren't any additional compounding paddings, it should line up.

The biggest questionmark, I think, is the max-width. Right now it defaults to the content width because it felt the most sensible for the header. But it could default to wide or full as well. 🤔

Sorry, I ran out of time yesterday to write down any notes after testing this!

It seems to work great with TT3 so far on a smaller resolution, or where the content fills the available screen width. I needed to add a top root padding value, as TT3's was set to 0px (for no specific reason), otherwise, the close button had no top padding (correctly, I believe).

Currently, the max-width doesn't work well for TT3 at larger resolutions, as the header is set to wide align:

So in this case, it would be better if it defaulted to --wp--style--global--wide-size. It's a shame it can't easily use the available space, I guess this is because of the position: fixed on the overlay.

Good thoughts. I'll update the value in the PR to --wp--style--global--wide-size, as that does use more of the available space and seems to cater to more common designs.

In the future, I like to think we can improve this code further, so it more naturally stays in sync with the content width of the header part.

Changed to wide width.

Changed to wide width.

This works great!

Cool! Let's test the core PR and see that nothing regresses in other themes, then we can land it! 🥳