*,
*:before,
*:after {
  box-sizing: border-box;
}

@function stack-shadows($length: 10, $x: -1, $y: 1, $color: #000) {
  $shadow: '';
  $i: 0;
  @for $i from 0 through $length {
    $shadow: $shadow + ($x * $i) + 'px ' + ($y * $i) + 'px 0 ' +  $color;
    $i: $i + 1;
    @if $i <= $length {
      $shadow: $shadow + ', ';
    }
  }
  @return $shadow;
}

@mixin stacked-shadows($args...) {
  box-shadow: #{stack-shadows($args...)};
}

.container {
  max-width: 980px;
  margin: 0 auto;
}

.brick {
  text-align: center;
  text-transform: uppercase;
  margin: 40px 0;
  position: relative;
}

.brick-front {
  display: inline-block;
  padding: 20px;
  border: 4px solid #000;
  background-color: #fff;
  position: relative;
  transition: all .2s ease;
  transform: translate3d( 0,0,0 );
  box-shadow: 0 0 0 0 rgba( 0,0,0,1 );

  &:hover {
    transform: translate3d( 10px,-10px,0 );
    @include stacked-shadows();
  }
}

.brick-set {
  margin: 40px 0;
  padding: 0;
  
  li {
    position: relative;
    list-style: none;
    padding: 0;
    display: inline-block;
    width: 50%;
    
    &:nth-child(even) {
      
      .brick {
        text-align: left;
      }
    }
    
    &:nth-child(odd) {
      z-index: 1;
      
      .brick {
        text-align: right;
      }
    }
  }
  
  .brick {
    margin: 0;
    
    .brick-front {
      transform: translate3d( 10px,-10px,0 );
      @include stacked-shadows();

      &:hover {
        transform: translate3d( 0,0,0 );
        @include stacked-shadows(0);
      }
    }
  }
}