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

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

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

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