Help please! :(

Hi all,

Bit of a newb when it comes to CSS, and need some help please! I want to change the background color of the sidebar widgets to light grey so it looks a bit distinct from white bg of the content body. How can I do this using css? I also need the light grey bg on widget side in mobile site too. You help will be much appreciated. My website is: http://www.fantasticfreebies.co.uk/

Thanks,
James