How to display my menu element on mobile ?

Hello, I am using the free GeneratePress for my site. It’s okay so far. I have the idea to stick the menu on both desktop and mobile. I get a code for that on this forum and it works fine(Thanks for WP contributors). Now I want to show the menu element on both desktop and mobile too. I tried many CSS and code, nothing seems to work for me. I have only 3 elements on my menu. I name my menu “bare_menu”. Can I receive any direction from here ?

This is the code I use to stick my desktop and mobile menu :

body {
background-color: #ffffff;
} site-navigation{

position: sticky;
position: -webkit-sticky;
top: -0.5rem;}

I hope this doesn’t affect why I can get it right for me !!

Thanks