Material shadow mixin

_material-shadow.scss

// Material-like shadowing
@mixin shadow($level: 1) {
  @if $level == 1 {box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);}
  @else if $level == 2 {box-shadow: 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);}
  @else if $level == 3 {box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);}
  @else if $level == 4 {box-shadow: 0 14px 28px rgba(0,0,0,0.25), 0 10px 10px rgba(0,0,0,0.22);}
  @else if $level == 5 {box-shadow: 0 19px 38px rgba(0,0,0,0.30), 0 15px 12px rgba(0,0,0,0.22);}
}

// Example usage
.card {
  display:block;
  @include transition(all 250ms);
  @include shadow(1);
  &:hover {
    @include shadow(3);
    @include transform(translateY(-5px));
  }
}