File Title covered the diff content at MR "Changes" tab on Firefox

Summary

The bar that contain title of each file of the MR "Changes" tab covered the content on Firefox the title moves along your scrolling and always cover the center of the file content.

Steps to reproduce

• use Firefox
• go to any MR that had multiple files change
• switch to Changes tab
• find the title bar covered the content.
• scroll down to see the title bar moving and keep cover the content

Example Project

You can check of any MR links on Gitlab. for example, !68891 (diffs)

What is the current bug behavior?

The title covert the content of the file

What is the expected correct behavior?

The title stays at the place they designed to stay

Relevant logs and/or screenshots

gitlab_bug

Output of checks

This bug happens on GitLab.com

Possible fixes

set a policy to test your implementation on all browsers.