you will want to change the -212px positioning because that is for the image sprite (one image that contains all the list images together and shown by coordinates).
I would imagine that your list bullet image is just a single one correct? If so, change that -212px to perhaps 0. Right now that css is saying position that image -212px to the left and 0px from the top. So your list bullet image is positioned off the page by -212 px 🙂