.wp-block-whatever {
	// Add responsiveness to common aspect ratios.
	&.wp-embed-aspect-21-9,
	&.wp-embed-aspect-18-9,
	&.wp-embed-aspect-16-9,
	&.wp-embed-aspect-4-3,
	&.wp-embed-aspect-1-1,
	&.wp-embed-aspect-9-16,
	&.wp-embed-aspect-1-2 {
		position: relative;

		&::before {
			content: "";
			display: block;
			padding-top: 50%; // Default to 2:1 aspect ratio.
		}

		iframe {
			position: absolute;
			top: 0;
			right: 0;
			bottom: 0;
			left: 0;
			width: 100%;
			height: 100%;
		}
	}

	&.wp-embed-aspect-21-9::before {
		padding-top: 42.85%; // 9 / 21 * 100
	}

	&.wp-embed-aspect-18-9::before {
		padding-top: 50%; // 9 / 18 * 100
	}

	&.wp-embed-aspect-16-9::before {
		padding-top: 56.25%; // 9 / 16 * 100
	}

	&.wp-embed-aspect-4-3::before {
		padding-top: 75%; // 3 / 4 * 100
	}

	&.wp-embed-aspect-1-1::before {
		padding-top: 100%; // 1 / 1 * 100
	}

	&.wp-embed-aspect-9-16::before {
		padding-top: 177.78%; // 16 / 9 * 100
	}

	&.wp-embed-aspect-1-2::before {
		padding-top: 200%; // 2 / 1 * 100
	}
}