How to fill the right gap?

Im using Wells template. I have no issues with images but if I make any kind of posts, it always have a huge gap on the right side. There is no way to fix this and I wonder if anyone can solve this problem?

i guess you need to centre or indent the entire site away from the left side. if you look at any website, there is a big gap on either side of the content (or on the right side - just go to google.com and there's a huge white space on the right side)