Bug with styles after interacting with the PreviewTab component.

[StanislavKozachenko]

Describe the Bug

The essence of the bug: after interacting with the PreviewTab component, the global styles change so that it affects an unrelated page.
Detected at least on the Media page.

Image

Reproduction

Steps to Reproduce

1. Go to the Media page and make sure everything is displayed correctly.
2. Next, go to the Themer page.
3. Click Preview button.

4. Then go back to the Media page.

Environment

Browser

Validations

• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.