CSS #categoriesContent

[abcschooldr]

I am trying to separate categories in the left hand side box with divider lines. I added this to the bottom of my css stylesheet at:/includes/templates/classic/css/stylesheet.css.

#categoriesContent, .sideBoxContent {
	 border-bottom:solid black 1px;
	}

I now have a line at the bottom, but not all of the way through. I want to add more categories, and it is already confusing to tell the difference between them.