Width of sidebar in Mystique

Hi Guys,

I have been trying out the Mystique theme on a number of WIP websites. I love it for its simplicity, but I have a problem. How do I change the width of the sidebar, or just go with a full width content for that matter? Sorry if I sound like a newbie, but I am. Thanks!

Websites with Mystique:
coralsatkeppelbaysingapore.com
duoresidencessingapore.co
brighthillcondosingapore.com