// @charset "UTF-8"; @mixin background-image-retina($file, $type, $width, $height) { background-image: unquote(image-url("#{$file}.#{$type}", true)); hey: length(a b c d); ho: unquote("hello"); hee: unquote(unit(10fudge)); @media (-webkit-min-device-pixel-ratio: 2), (-moz-min-device-pixel-ratio: 2) { & { background-image: image-url("#{$file}@2x.#{$type}"); -webkit-background-size: $width $height; } } } $x: foo; $y: bar; div { @include background-image-retina(test, png, 100px, 300px); fudge: walnut; } span { blah: "#{$x} #{$y}"; bleh: image-url("#{$x} #{$y}"); } @mixin foo($x, $y) { foo-x: $x; foo-y: $y; } div { @include foo(1, 2); @include foo($y: 2, $x: 1); } @mixin bar($x, $y: default) { bar-x: $x; bar-y: $y; } div { @include bar(1, 2); @include bar(1); @include bar($x: n1, $y: n2); @include bar($x: n1); blah: unquote("hello"); }