@mixin pixelated {
  /* Older versions of FF          */
  image-rendering: optimizeSpeed;
  /* FF 6.0+                       */
  image-rendering: -moz-crisp-edges;
  /* Safari                        */
  image-rendering: -webkit-optimize-contrast;
  /* OS X & Windows Opera (12.02+) */
  image-rendering: -o-crisp-edges;
  /* Awesome future-browsers       */
  image-rendering: pixelated;
  /* IE                            */
  -ms-interpolation-mode: nearest-neighbor;
}

@mixin shadow-border($size, $color, $radius: $size) {
  box-shadow:
    -#{$size} -#{$size} $radius $color,
       $size     $size  $radius $color,
    -#{$size}    $size  $radius $color,
       $size  -#{$size} $radius $color
  ;
}