Windows Mac 共通　ブラウザ別指定

color: #fff;
@include ie {
	color: #000;
}

のような感じでmixinを呼び出します。

//Win IE11
@mixin ie {
	@at-root _:-ms-lang(x)::-ms-backdrop, & {
		@content;
	}
}

//Win Edge
@mixin edge {
	@supports (-ms-ime-align:auto) {
		@content;
	}
}

//Win Mac Chrome
@mixin chrome {
	@media screen and (-webkit-min-device-pixel-ratio:0){
		@content;
	}
}

//Win Mac Firefox
@mixin firefox {
	@-moz-document url-prefix(){
		@content;
	}
}