@function linear-gradient($pos, $gradients...) {
    $type: linear;
    $pos-type: type-of(nth($pos, 1));

    // if $pos doesn't exist, fix $gradient
    @if ($pos-type == color) or (nth($pos, 1) == "transparent") {
        $gradients: zip($pos $gradients);
        $pos: false;
    }

    $type-gradient: $type, $pos, $gradients;
    @return $type-gradient;
}
