_em.scss

/// Converts a target value in pixels to its associated value in ems based on a context.
/// @param {Integer | Pixels | List} $target - The target size in either pixels or its integer equivalent.
/// @param {Map} $context [$baseFontSize] - The context size in either pixels or its integer equivalent.
/// @return {Number} The target's value in ems within the given context.
/// @example
/// em(12)
/// // 0.75em
/// @example
/// em(12 16, (context: 24))
/// // 0.5em 0.6666em
@function em($target, $options: ()) {
	$options: map-merge((
		context: $baseFontSize
	), $options);

	$output: null;
	$context: map-get($options, context);

	@if type-of($target) == list {
		$output: unquote('') !default;

		@each $value in $target {
			$value: em($value, (context: $context));

			$output: append($output, $value);
		}
	}
	@else {
		$target: parseInt($target);
		$context: parseInt($context);

		$output: ($target / $context) * 1em;
	}

	@return $output;
}