CSS text-align: center; is not centering things

I assume you want all the items next to each other, and the whole thing to be centered horizontally.

li elements are display: block by default, taking up all the horizontal space.

Add

div#footer ul li { display: inline }

once you’ve done that, you probably want to get rid of the list’s bullets:

div#footer ul { list-style-type: none; padding: 0px; margin: 0px }