/// Margins for a main/top heading in the center column.
///
/// The heading has $heading-margin-top on desktop
/// but no top margin on mobile.
/// A bottom margin is not defined.
@mixin marginForCenterColumnHeading() {
	@include marginForCenterColumn( $heading-margin-top, 0 );

	@media ( max-width: $breakpoint ) {
		margin-top: 0;
	}
}