centering a navbar when screen resizes

I am trying to centre my navbar, after my screen resizes to a smaller size. I have made sure that my class containing my navigation: .menu has the following

display: 
inline-block; 
margin: 0px auto;

It still doesn't centre...

However, my logo contained in the div above, has the same properties and it is able to centre when the screen resizes.

Can anybody give me some insight?