Refactor navbar to address some resolutions incompatibility

[evandrosaturnino]

NavBar requires some refactoring/touch-ups because in some resolutions it looks off. For example this is how it looks for 1173px width:

[michalsmiarowski]

Here is a discussion about it for refernece: #105 (comment)

It also looks like the navbar is slightly skewed to the right side instead of being centered.