how to achieve 100% screen width for widget backround

Hello!
I put text widget in the "mainbody" area, set grey background in widget rules, and in the output i have text with grey background only in central part of the screen (which i guess is specified in Layout -> Theme Width ->1045 ) and white fields on sides.
http://s2.ipicture.ru/uploads/20130717/vpt22FSA.jpg


How can i achieve grey background for whole 100% of screen width?

Thanks in advance!

Could You post an url to your site?

I'm sorry, it's still on a localhost... I can post some screenshots or tell you information which you need to help me solve this problem.

http://s2.ipicture.ru/uploads/20130718/11oQAiQe.jpg

Mainbody is placed in a fixed width element, that is not 100% of the screen.
Perhaps You would consider placing the module in gkBottom1 position, which allows screen 100% width. If You want it first, You can simply rearrange modules in widget area.

Thanks a lot! You are right. I can do just that.
But could you please tell me more about "rearranging modules in widget area"?
Is it by making changes in "widgets.json" file? If rearrangements of modules are being made in this file, wouldn't
this anyhow affect functioning of the whole Creativity template? Or it's just fine?
Thanks again!

"rearranging modules in widget area" - isnt that hard - Its WP - most things are easy here. Just go to widgets, open Bottom I Widgets (or any other You would like to rearrange) and move them up and down inside of the area or even between areas.