// Box Sizing
// ==========

// Box Sizing
// ----------
// Check for an existing support mixin, or provide a simple fallback.
// - $model: <box-sizing>
@mixin susy-box-sizing(
  $model: content-box
) {
  @if $model {
    @if susy-support(box-sizing, (mixin: box-sizing), $warn: false) {
      @include box-sizing($model);
    } @else {
      $prefix: (moz, webkit, official);
      @include susy-prefix(box-sizing, $model, $prefix);
    }
  }
}