Sass: Create Reusable CSS with Mixins help

I have gotten the test to pass, however out of curiosity I tried to use the sample box-shadow code provided in the explanation and that code does not work. Cannot find a solution to this and I am very curious about what is going on.

<style type='text/sass'>
  @mixin border-radius($radius) {
    -webkit-border-radius: $radius;
    -moz-border-radius: $radius;
    -ms-border-radius: $radius;
    -border-radius: $radius;
  @mixin box-shadow($x, $y, $blur, $c) { 
    -webkit-box-shadow: $x, $y, $blur, $c;
    -moz-box-shadow: $x, $y, $blur, $c;
    -ms-box-shadow: $x, $y, $blur, $c;
    box-shadow: $x, $y, $blur, $c;

  #awesome {
    width: 150px;
    height: 150px;
    background-color: green;
    @include border-radius(15px);
    @include box-shadow(5px, 5px, 5px, blue);

<div id="awesome"></div>

Really good question. The information in the challenge does not seem correct.

should be

  @mixin box-shadow($x, $y, $blur, $c) { 
    -webkit-box-shadow: $x $y $blur $c;
    -moz-box-shadow: $x $y $blur $c;
    -ms-box-shadow: $x $y $blur $c;
    box-shadow: $x $y $blur $c;

With no commas between the variables. Good eye! Test that and see if it works for you.

Ref Challenge:

Yes after about 2 hours of playing around with syntax I actually came to that solution, and yes it does in fact work. Thank you a ton!