Quick little mixin to automatically vendorize properties/values that might need to be vendorized (listed in $vendor-properties and $vendor-values). Originally written for http://html5up.net/spectral.
@include vendor('transform', 'rotate(-45deg)');
@include vendor('transition', ('transform 1s ease', 'opacity 0.5s ease'));
@include vendor('display', 'flex');
@include vendor('flex-wrap', 'wrap');
@include vendor('background-image', ('linear-gradient(top, rgba(0,0,0,0.5), rgba(0,0,0,0.5))', 'url("../images/banner.jpg")'));