CSS / small browser view on 3 column theme

[info@.....com]

Having a weird conflict with my J template and can't seem to get the white background to line up in the main content area. Tried a few things and seems to want to shift the cart content areas off to the side.. notice it the most in Chrome and IE, and a little in FF:

http://www.candleray.com/led/cart

Also, is there a way to stack the three columns vertically on smaller browsers? Things get pretty squishy on tablets/smaller laptops

Many thanks Stan!