@mixin transition-duration($dur: 0.3s) {

-webkit-transition-duration: $dur;
   -moz-transition-duration: $dur;
     -o-transition-duration: $dur;
        transition-duration: $dur;

}

@mixin transform($translate: translate3d(0px, 0px, 0px), $scale: scale(1)) {

-webkit-transform: $translate $scale;
   -moz-transform: $translate $scale;
     -o-transform: $translate $scale;
        transform: $translate $scale;

}