How to have a full width logo img header + send navbar to bottom of page ?

Site URL: https://bieresansalcool.co/en/

Hi, I'd like to convert my current business fully custom html/css website to a Squarespace just so we can get the e-commerce features and CMS behind it. And honestly it's the first website I code so my code is not clean lol. My problem is that our current website header and navbar is not quite standard in terms of design. Please see URL.

Basically on desktop  we want to have a logo header that's 100vw and send the navbar to the bottom of the page. However, on mobile and responsive, we want to keep having the hamburger menu on top, make the navbar disappear, and let's say have a logo that's 80vw for leaving enough space for the hamburger menu.

Thanks for your help!

You can add Logo, Navigation.

Then we will give the code to float all navigation to bottom of site, & make logo fullwidth

(on desktop only)

On mobile, the site will use default layout with burger on left, logo middle.