Icono-gear does not work on latest version of Firefox Developer Edition

[CharCoding]

The icono-gear class only shows 2 nested circles instead of gears.
It works fine in IE 11. Haven't tested on other browsers.
In Firefox Developer Edition:

In IE 11:

I also made my own version for a gear: JSFiddle. Works fine on both browsers.

[saeedalipoor]

Thanks @CharCoding, for firefox it was a known issue, and i will apply some update to fix this.
I like your fiddle :) thanks a lot.