[BUG] the style in devtools panel doesn't work

[Xisney]

What happened?

I import a stylesheet in devtools panel, but it not works in the page.

The demo looks like:

In fact, the dev bundle has included the css file, but it not contains in the template. This should be the cause of the abnormality.

Version

Latest

What OS are you seeing the problem on?

MacOSX

What browsers are you seeing the problem on?

Chrome

Relevant log output

No response

(OPTIONAL) Contribution

• [ ] I would like to fix this BUG via a PR

Code of Conduct

• [X] I agree to follow this project's Code of Conduct
• [X] I checked the current issues for duplicate problems.