Making changes to checkboxes part 2

Hello all, I asked this question about a month ago: How can I change the Appearance of the checkboxes in Nintex forms 

I thought I had the answer but it looks like the solution I arrived on, hides the check boxed when they are printed, and the solution others suggested works well, but only in internet explorer and to a degree chrome.  I tried adding in a line of

-moz-appearance: none; but it had no affect.  Help me nmarples you're my only hope.