How do I give all list items a max-width without having all of them fill that width

How do I give all list items a max-width without having all of them fill
that width

http://cdpn.io/gsDHK
Link to Codepen ^
I have a problem with this list. I need to break the words at a certain
point on all of these, but I am unable to change the HTML within the list
items.
I set a max-width of 72px on each list item. But Now they are all 72px
wide. They should be auto width with a max width of 72px. The white space
on either side of each list item has to be even. As you can see on the
Learning Center link, there is more white space than on the others.