five-for-the-future/themes/wporg-5ftf/css/objects/_hero.scss

// Defined here so we can use `ms`.
$size__spacing-unit: ms( 4 );

/* Fills 100% of the screen on mobile, and 100% of the content area on desktop */
.is-style-wporg-hero {
	position: relative;
	left: -#{ $size__spacing-unit };
	width: calc( 100% + ( 2 * #{ $size__spacing-unit } ) );
	max-width: calc( 100% + ( 2 * #{ $size__spacing-unit} ) );
	clear: both;
	margin-bottom: 0;

	@include breakpoint( $breakpoint-tablet ) {
		position: inherit;
		left: inherit;
		width: inherit;
		max-width: inherit;
		clear: inherit;
		margin-bottom: 1em;

		&.wp-block-group {
			margin-top: -8rem;
		}
	}
}