Centering Mixin

  /*
  * @seen on https://css-tricks.com/snippets/sass/centering-mixin/
  */
  @mixin center($horizontal: true, $vertical: true) {
    position: absolute;
  
    @if ($horizontal and $vertical) {
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
    } @else if ($horizontal) {
        left: 50%;
        transform: translate(-50%, 0);
    } @else if ($vertical) {
        top: 50%;
        transform: translate(0, -50%);
    }
  }