@mixin background-adaptive($image) {
  $regex: "\.([a-z]+)$";
  background-image: url($image);

  @media ($media-m) {
    background-image: url("#{replace($regex, $image, "-desktop.$1")}");
  }
}

@mixin background-fill($type: cover) {
  background-repeat: no-repeat;
  background-position: center center;
  background-size: $type;
}

@mixin background-fixed($image) {
  @include background-adaptive($image);
  background-attachment: fixed;
}