Hi carlucci
It relates to grid system, both logo (left side) + menu (right side) belongs to a row which has 12 grids:
As you can see the logo has 2 grids, if you want to reduce the width, you can change to 1 grid - change from 'col-lg-2' to 'col-lg-1' and increase the same grid for the right: 'col-lg-10' to 'col-lg-11'. Just make sure that the total grid equals to 12.
Regards