Main menu centered and without logo

Hello!
I would like to have the main menu centered and without the logo, (the logo is already in the top bar). But I have two drawbacks:
1) When I remove the logo image in the main menu, it is automatically replaced by the site name in text format. I have made it invisible:
a.site-title.site-logo-text{
visibility: hidden;
}
2) But it still takes its width…. When I choose to align the menu to the center, it is not aligned properly, it creates a double line.
How can I correct this?
Thank you!

Translated with https://www.DeepL.com/Translator (free version)

The page I need help with: [log in to see the link]