The size mixin (replacement for wdith/height combos)

Tired of setting width and height? Use this size mixin as proposed in Shorthand for width-height CSS longhands

@mixin size($width, $height) {
  width: $width;
  height: $height;
}

@mixin square($size) {
  @include size($size, $size);
}

Works with

.foo { 
    size: 10px; 
}

or

.bar { 
    size: 2em 3em; 
}