Additional, fixed navigation for mobile does not want to change width :(

Helo everyone
I just published my portfolio, and I’m trying to improve it with additional navigation to scroll to different part of case study.

I had my idea of developing it, and I am almost there but the width is not responding to any changes.

Please help, it can be an awesome feature, but not when it looks like that :((
PS This nav is vissible only on mobile devices!

Have a good day everyone :sun_with_face:

Here is my site Read-Only: LINK