Box-shadow supports single or multiple arguments.
Single Box Shadow
{% highlight scss %}
@include box-shadow(0 0 5px 3px hsla(0, 0%, 0%, 0.65));
{% endhighlight %}
Multiple Box Shadows
{% highlight scss %}
@include box-shadow(1px 1px 5px 1px green, -1px -1px 5px 1px blue);
{% endhighlight %}