Remove this "space"

#primary {
	float: left;
	margin: 0 -26.4% 0 0;
	width: 100%;
}
...
#secondary {
	float: right;
	margin-right: 7.6%;
	width: 18.8%;
}

to pull the sidebar closer to the center:
for instance, try to change -26.4% to -30.4%
and 18.8% to 22.8%

generally, this seems to be the area in style.css to play with.