Indenting Custom Blade Directives

I have some custom Blade directives ( @group & @endgroup )

I added them here:
File | Settings | Languages & Frameworks | PHP | Blade

But am uncertain how to tell PhpStorm how to recognise that @group is the start and @endgroup is the end and be able to indent code within.

e.g. @if is not indented and obviously with more code this gets more visually confusing.

@group('G_heading')

@if (get_sub_field('type'))
 <h1>@sub('heading')</h1>
@endif

@endgroup

Thanks in advance!