Checkboxes Mozilla Cross-Browser issue

Hello,
I'm experiencing some issues with my checkboxes on Mozilla. The checkbox (on http://ift.tt/1pjpBVa) works totally fine on Chrome, but on Mozilla it looks like the default checkbox. I tried and added -moz-appeareance: none, but as it seems it's not reading the pseudo (::before and ::after) elements. I really can't understand and see why it's not displaying as supposed to.

Best Regards,
DSaidov