$base-font-size: 16px !default;

@function rem-calc($value, $base-value: $base-font-size) {
	$value: strip-unit($value) / strip-unit($base-value) * 1rem;
	@if ($value == 0rem) {
		$value: 0;
	} // Turn 0rem into 0
	@return $value;
}
@function rem($values) {
	$sizes: null;

	@if length($values) > 1 {
		@each $size in $values {
			@if $sizes == null {
				$sizes: #{rem-calc($size)};
			} @else {
				$sizes: $sizes #{rem-calc($size)};
			}
		}
	} @else {
		$sizes: rem-calc($values);
	}

	@return $sizes;
}

@function px-calc($value, $base-value: $base-font-size) {
	$value: strip-unit($value) * (strip-unit($base-value) * 1px);
	@if ($value == 0px) {
		$value: 0;
	} // Turn 0px into 0px
	@return $value;
}

@function px($value) {
	$sizes: null;
	@if length($value) > 1 {
		@each $size in $value {
			@if $sizes == null {
				$sizes: #{px-calc($size)};
			} @else {
				$sizes: $sizes #{px-calc($size)};
			}
		}
	} @else {
		$sizes: px-calc($value);
	}
	@return $sizes;
}

@function to-px($value) {
	@if type-of($value) == "number" {
		@if unit($value) == "px" {
			@return $value;
		} @else if unit($value) == "rem" {
			@return strip-unit($value) * $base-font-size;
		} @else if unit($value) == "" or unit($value) == null {
			@return #{$value}px;
		} @else {
			@debug "Can't #{$value} to px";
			@return $value;
		}
	} @else {
		@return $value;
	}
}