Firefox retina support for background images (mediaqueries)

Question

I developped several websites using mediaqueries for making them retina ready. On firefox I now see that all background images (managed by mediaqueries) are blurry, not retina ready.

Is this normal? Why firefox does not support the mediaqueries for pixel-ration yet?

Ex:

@media only screen and (-webkit-min-device-pixel-ratio: 2), 
only screen and (min-device-pixel-ratio: 2) { ... }

Thanks for your help.

Answer 1

Firefox does support pixel ratio media queries with prefixes:

-moz-device-pixel-ratio