Sass Mixin to position child in parent, relative to parent's center

centerer.sass

@mixin centerer($horizontal: true, $vertical: true, $offsetH: 0%, $offsetV: 0%) {
  position: absolute;
  @if ($horizontal and $vertical) {
    top: 50% + $offsetV;
    left: 50% + $offsetH;
    transform: translate(-50%, -50%);
  } @else if ($horizontal) {
    left: 50% + $offsetH;
    transform: translate(-50%, 0);
  } @else if ($vertical) {
    top: 50% + $offsetV;
    transform: translate(0, -50%);
  }
}