The address is centered in the footer. Your problem is that you want the address centered on section#main, and the footer isn't in the section#main, it's in div#container, resulting in an address centered to the whole container.
However, since your aside has a static width of 200px, we can add that as a margin into footer>address, so that it centers the content accordingly.
So, we want on footer address is:
margin-right:200px;
but since we already have
margin-top:25px;
we can just delete that margin-top line and say both with:
margin:25px 200px 0 0;
which is shorthand for margin top 25px right 200px bottom 0 left 0.
Finally, the correct way to post this would be on JSFiddle, it's super easy to figure out, and I put my solution for your problem here: