Font Awesome Sass Helper and Mixin

fa.scss

// Font Awesome Helper (font-awesome/scss/_core.scss)
%fa {
	display: inline-block;
	font: normal normal normal #{$fa-font-size-base}/#{$fa-line-height-base} FontAwesome; // shortening font declaration
	font-size: inherit; // can't have font-size inherit on line above, so need to override
	text-rendering: auto; // optimizelegibility throws things off #1094
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

// Font Awesome Mixin
@mixin fa($icon) {
	@extend %fa;
	content: $icon;
}