@mixin fluid-aspect($ratio: 1 1, $selector: "> :first-child") {
	$selector: unquote($selector);

	padding-bottom: percentage(nth($ratio, 2) / nth($ratio, 1));
	position: relative;

	#{$selector} {
		left: 0;
		height: 100%;
		position: absolute;
		top: 0;
		width: 100%;
	}
}