@mixin add-checkbox-placeholder {

$placeholder-width: units(4);
$placeholder-margin: units(1);

text-indent: ($placeholder-width + $placeholder-margin) * -1;

&::before {
  content: " ";
  display: inline-block;
  height: units(2);
  margin-left: units(-0.5);
  margin-right: units(1.5);
  width: $placeholder-width;
}

}