Bottom-border doesn't span across full paragraph

Hello,

I set a bottom-border on the recent posts widget in the sidebar so that each title is separated by a dotted line. However, the last post only underlines the text and doesn’t span across the whole paragraph. I want it to span full-width of the paragraph, not the text.

Here is the site link.

This is the CSS I added to modify it.

#rightbar ul li {
   line-height: 120%;
   padding-bottom: 6px;
   padding-top: 6px;
   border-bottom: 1px dotted #502821;
}

Thanks.