Test If Browser Supports CSS Rules

To test if browser supports some #CSS rules, do following:

@supports (backdrop-filter: blur(5px)) {    backdrop-filter: blur(5px);}

This @mixin will only apply rule if browser support backdrop filtering:

@mixin can_backdrop {  @supports (    (-webkit-backdrop-filter: blur(5px)) or     (backdrop-filter: blur(5px))  ) {    @content;  }}