Resize widget sidebar

[joel19]

Hi, I am using Guru theme and I am using widgets on my sidebar. Is there any way I can style the sidebar.
Actually I want my sidebars width to be reduced and increase the content width. I tried every other way to do it but I wasn't just successful.
Can anybody just help me out in this?

I use the theme here: joelifernandes.com

[joel19]

And BTW sorry it was by mistake I posted this thread in a wrong section. oops!!! :-s