Reconsider add_editor_style.

[tcmulder]

Using add_editor_style in includes/blocks.php causes @container querries to break, and it looks like there are many other issues. Some use enquque_block_editor_assets as a workaround: is that plausible, now that gutenberg is within an iframe?

Secondarily, does that allow Browsersync to work on the back-end...? 🤞

[tcmulder]

Could potentially test this via the aquamin/grd Grid block.

[tcmulder]

Note: this sorta works, except for some reason it won't load on the back-end over the Browsersync localhost proxy. I can't figure out why, which makes implementation feel risky.

It does however fix the original issue, allowing things like @container queries to work on the back-end. Except for localhost via Browsersync on the back-end, everything works just as I was hoping.

[tcmulder]

Got this working! It sorta bypasses add_editor_style for now while still using it... check out blocks.php for comments on how that works.

[strarsis]

New editor styles transformation approach using PostCSS is now merged (many thanks @zaguiini)!