Clearer-DIV Method
In order to make the footer have left- and right-floated DIVs inside it, we add a "clearer" DIV just before closing the footer.  But that causes an unwanted margin to appear beneath the footer.

The clearfix method does the same thing, only worse.

Proposed solutions:

add display:table to #footer (doesn't work)

add display:table-cell to #footer (doesn't work)