Looks weird in firefox

[Alexnortung]

When accessing the demo in firefox, the header seems to jump back and forth.
Is there a fix for this?

[FilipChalupa]

I'm not sure what you mean. Do you have a screencast by any chance?

This is how it behaves in my latest Firefox on Windows.

[Alexnortung]

Screencast from 2023-02-11 19-21-58.webm
The jumps you see happens when I scroll either up or down