-webkit-transform: translate3d(0, 0, 0);

I have a special rule in my css to target a webkit webview on ios which has a layout rendering problem. This is a known issue. The only fix for this is adding this rule: -webkit-transform: translate3d(0, 0, 0); This gives some side effects in my apllication because the z-indexation is messed up. This was an acceptable trade-off when only webkit browsers are concerned. Suddenly I see the side-effect occur in Firefox Quantum. It seems the css vendor-prefixed rule is also executed. I don't understand that. Isn't the browser supposed to only run it's own vendor prefixed classes? in this case the -moz- prefixed classes? See the screenshot Although only the `-webkit-transform` is defined is also shows the non-prefixed rule `transform:`