Post Editor: 40vh padding applied to the bottom is overwritten with zero

[t-hamano]

Description

In WP6.6, when useRootPaddingAwareAlignments is false in theme.json, the expected 40vh padding below the content in the post editor is overwritten with zero.

This makes it difficult to click below the content and insert a new block.

I think the issue is related to the CSS selector that applies the zero padding changing from body to :root :where(body), which has a higher specificity.

WP6.5

✅ useRootPaddingAwareAlignments: true

✅ useRootPaddingAwareAlignments: false

WP6.6

✅ useRootPaddingAwareAlignments: true

❌ useRootPaddingAwareAlignments: false

Step-by-step reproduction instructions

• Define the theme.json for your block theme as follows:

  {
  	"version": 2,
  	"settings": {
  		"layout": {
  			"contentSize": "620px",
  			"wideSize": "1280px"
  		}
  	}
  }

• Open the post editor and insert some content.
• Scroll to the very bottom of the content.
• There will be no padding below the content.

Screenshots, screen recording, code snippet

Actual

Expected

Environment info

WordPress 6.6 RC2 and latest Gutenberg plugin

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[talldan]

I don't know much about useRootPaddingAwareAlignments. 🤔

I guess the 40vh rule should be bumped to 0,1,0 specificity?