Premium Content Block: Button outline style not working

[alaczek]

Quick summary

Applying "outline" style to buttons inside the Premium Content Block doesn't work as expected - it doesn't match the active theme's outline style for buttons.

Steps to reproduce

Simple Sites:

1. Activate Illustratr theme
2. Add standard Buttons block to page, and set style to Outline.
3. Add a Premium Content block, and set one of the style of one of the buttons to Outline. Note the text color changes to gray, but the background is not transparent, which makes the text unreadable.

Also replicated in Assembler and TT4 themes - in that case there was no visual difference after applying style "Outline" to one of the buttons.
This was originally reported in Automattic/themes#7958 but I moved it here after investigating.

What you expected to happen

I expected the outline style to be applied the same way it works for core Buttons block as per theme style.

What actually happened

After changing a button style to "outline" it either doesn't change appearance at all (TT4, Assembler), or looks unreadable (Illustratr).

Impact

Some (< 50%)

Available workarounds?

No but the platform is still usable

If the above answer is "Yes...", outline the workaround.

No response

Platform (Simple and/or Atomic)

No response

Logs or notes

No response

[github-actions]

OpenAI suggested the following labels for this issue:

• [Feature Group] Appearance & Themes: The issue is directly related to the appearance of buttons within the Premium Content Block and how they align with theme styles.
• [Feature] Core Blocks: The issue involves the Buttons block, which is a part of the core Gutenberg blocks for creating content.
• [Feature] Premium Automattic Themes: The issue specifically mentions the Illustratr, Assembler, and TT4 themes, which are premium themes provided by Automattic.
• [Feature] Global Styles: The problem pertains to how the outline styling of buttons does not conform to the expected global styles of the active theme.

[jeherve]

Moving this to the Jetpack repo, where the Premium content block is developed.