I have custom-made web fonts used on my site. To style my rendering output, I used the following code:
//-webkit-text
Well, Firefox does not support something like that.
In the reference page from Mozilla specifies font-smooth as CSS property controls the application of anti-aliasing when fonts are rendered, but this property has been removed from this specification and is currently not on the standard track.
This property is only supported in Webkit browsers.
If you want an alternative you can check this: