Responsive

[sarahdee]

I'm looking into your framework for a little startup venture.
I downloaded the demo and have been poking around to see if it will suits my needs and to make sure my html/CSS skill level is adequate to customise blocks the way i'd like to.
So far no trouble except when the page shrinks down to mobile size.
Which .css file styles the mobile version of the site?
do I only get access to it with the full version.