Project navbar remains visible above modal and gallery image backdrops #8021

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal

What browsers are you seeing the problem on?

Chrome (including Arc, Brave, Opera, Vivaldi), Microsoft Edge

Describe the bug

When opening a modal or a gallery image on a project page, the project navbar stays visible on top of the modal/gallery backdrop instead of being covered by it.

Steps to reproduce

1. Navigate to any project page (e.g. mod or collection).
2. Open a gallery image or modal.

Expected behavior

The project navbar should be placed behind the modal or gallery image backdrop.

Additional context

This appears to be caused by an injected stylesheet that applies a z-index of 200 to the navbar.