joomla - Increase Joomla 3 responsive menu collapse point using only CSS

Question

I built a Joomla 3.4.3 custom template using only standard CSS, no LESS or SASS or custom javascript.

My menu has quite a few items and thus the last items overflow to a second line long before the standard collapse point of around 980px.

Is it possible to use standard CSS to increase the collapse point to 1310px?

Any help would be much appreciated.