[SOLVED] Varying the styling for each widget

I am a newbie to both Wordpress and Atahualpa.
I am making a website and I wanted to have a border around the widget container in my left sidebar. Therefore in the Atahualpa settings - Style Widgets - Widget container, I added the following style:
margin: 25px 0 25px 0;
border: solid 3px #875500;
-moz-border-radius: 10px;
-webkit-border-radius: 10px;
border-radius: 10px;
padding: 10px 10px 10px 10px;

This works fine for me except that it makes a border around all the widgets in every sidebar. I do not really know if this style change was placed in the right place or not. Can someone please explain to me how I can have the border JUST for the widget in the left sidebar? At one point I figured that if I could find the place where each widget gets it's styling from, I could change the color of the border to the same color of the background - that way it won't be seen. But I can't figure out where it is that I need to make the change.

Can someone please point me in the right direction?
Thank you