What happened?

Description

Markdown UI Elements are styled differently when in Preview.

Steps to reproduce

1. Create a UI Markdown Element
2. Make sure that 'Display Content in Pane' is set to true
3. Check Entry to notice that UI Markdown Element has a gray background
4. Open up the default preview target, {url}

Expected behavior

The UI Markdown Element should have a gray background since 'Display Content in Pane' is set to true

Actual behavior

The UI Markdown Element has a white background, but it still gets the padding/border from the 'Display Content in Pane' setting

Craft CMS version

5.6.10.1

PHP version

No response

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions