@mixin typography( $font-family: null, $font-size: null, $line-height: null, $font-weight: null, $letter-spacing: null ) {

    @if type-of($font-family) == map {
        $props: $font-family;
        @each $prop, $value in $props {
            @include _prop( $prop, $value );
        }
    } @else {
        @include _props(
            (font-family, $font-family),
            (font-size, $font-size),
            (line-height, $line-height),
            (font-weight, $font-weight),
            (letter-spacing, $letter-spacing)
        );
    }
}