Modifying the layout in fspring

I really like the fspring theme but I’m having some trouble with the layout. I’m trying to widen the white layout that the content is shown on but everytime I edit it only the content widens and it goes beyond the white layout. This is what it looks like:

https://i10.tinypic.com/2jakryd.png

What I’m editing is this:

—–
#wrap {
width: 980px;
overflow: hidden;
position:relative;
margin: 0px auto;
}
#content {
width: 484px;
float: left;
display:inline;
text-align: justify;
padding: 10px;
margin: 8px;
——–

No matter what approach I take I can’t remedy the problem. Any help is appreciated.