@define-mixin shadow $x: 0, $y: 1px, $blur: 2px, $color: rgba(0,0,0,0.37) {
  box-shadow: $x $y $blur $color;
}

@define-mixin no-shadow {
  box-shadow: none;
}

@define-mixin inset-shadow $x: 0, $y: 1px, $blur: 2px, $color: #aaa {
  box-shadow: inset $x $y $blur $color;
}

@define-mixin text-shadow $color: #fff, $x: 0, $y: 1px, $blur: 0 {
  text-shadow: $color $x $y $blur;
}