ScoutingRediscovered on "centering bottom widgets in Mog Theme"

Hello! I'm using Mog Theme on a site that is in the alpha stage right now, and I would like to make sure the bottom widgets remain centered on any monitor size or zoom level. If anyone tell me how to do this, I would appreciate it very much. I have beginner level experience in CSS.

Here is my site: http://www.therenaissancemind.com/

Here is the current css from main.css:

/* Secondary area */
#secondary{
	margin: auto 23%;
	padding: 2em 0;
	border-top: 0px solid #AAA;
}

#search{
	text-align: center;
	float: none;
	width: auto;
	margin-bottom: 1.5em;
}

aside.widget{

	float: left;
	margin: 0 1em 0 0;
	width: 13em;
	padding: 5px;

}