Compress Menu on Mobile Devices

Hi! When I try to view my website through a mobile devices, the header navigation menu becomes ugly as it wraps around the screen. Is it possible for me to compress it into a menu icon of sorts?

And can you let me know if removing that menu also fixes how weird my site banner in the masthead looks on mobile? Thank you!

Here’s my website: http://www.gmrplusinc.com