How do I change the responsive breaking points?

I added a customer home image/link and a search bar to the front and back of my primary navigation, respectively.

I think that these added items are screwing up the width when Parabola calculates when to switch to Mobile version and the dropdown menu version of the navigation. As the window shrinks the search bar and the last navigation link drop down and create a second line of menu items.

Any ideas on how/where I would edit the point at which Parabola jumps to Mobile version so this kicks in before my nav gets jacked?

Thanks in advance for any help.