////
/// @group utilities
////

/// A mixin that overwrites Bootstrap 4's `box-shadow` mixin. Shadows set to
/// `c-unset`, `clay-unset`, `null`, or an empty list are dropped from the
/// arglist. The remaining shadows are joined into a comma separated list.
/// @param {Arglist} $shadow

@mixin box-shadow($shadow...) {
	$enable: if(
		variable-exists(enable-shadows),
		$enable-shadows,
		if(variable-exists(cadmin-enable-shadows), $cadmin-enable-shadows, true)
	);

	@if ($enable) {
		$shadows: ();

		@each $value in $shadow {
			@if (
				(not clay-is-map-unset($value)) and
					($value != null) and
					($value != ())
			) {
				$shadows: append($shadows, $value, comma);
			}
		}

		@if (length($shadows) > 0) {
			box-shadow: $shadows;
		}
	}
}