@mixin sass circle

circle.scss

@mixin circle($width, $color) {
  width: $width;
  height: $width;
  background: $color;
  -webkit-border-radius: $width/2;
     -moz-border-radius: $width/2;
          border-radius: $width/2;
}
 
.circle {
  @include circle(200px, #999);
}