Navigation Bar & Logo Alignment (7.1)

Hello!

I'm creating a shop, and having a difficult time adjusting to 7.1.

My site: https://madhype.squarespace.com/
Password: Taste

I would like to copy the top portion (logo and nav) of the Revolve site as close as possible:
https://www.revolve.com/

I'm trying to extend the navigation bar the full width of the page, and make a black background underneath. Would anyone be able to help me with a code? I found one in my search, but afraid it caused issues with running on top of the shop logo when the browser window narrows.

Any other changes to help get the header closer to Revolve is much appreciated! Thanks!

Hi. Do you still need help on this?