@mixin fontSize( $index: 0, $base-size: 1.6em, $ratio: 1.62 ) {

	@if $index > 0 {
		@for $i from 1 through $index {
			$base-size: $base-size * $ratio;
		}
		font-size: 				$base-size;
	}
	@else {
		font-size: 				$base-size;
	}
}

//10.000 * 1.618 = 16.180
//16.180 * 1.618 = 26.179
//26.179 * 1.618 = 42.358
//42.358 * etc.