themes-wordpress/seedlet/assets/sass/blocks/heading/_editor.scss

.wp-block-heading h1, h1, .h1,
.wp-block-heading h2, h2, .h2,
.wp-block-heading h3, h3, .h3,
.wp-block-heading h4, h4, .h4,
.wp-block-heading h5, h5, .h5,
.wp-block-heading h6, h6, .h6 {
	clear: both;
	font-family: var(--heading--font-family);
	font-weight: var(--heading--font-weight);

	strong {
		font-weight: var(--heading--font-weight-strong);
	}
}

.wp-block-heading h1, h1, .h1 {
	font-size: var(--heading--font-size-h1);
	letter-spacing: var(--heading--letter-spacing-h1);
	line-height: var(--heading--line-height-h1);
}

.wp-block-heading h2, h2, .h2 {
	font-size: var(--heading--font-size-h2);
	letter-spacing: var(--heading--letter-spacing-h2);
	line-height: var(--heading--line-height-h2);
}

.wp-block-heading h3, h3, .h3 {
	font-size: var(--heading--font-size-h3);
	letter-spacing: var(--heading--letter-spacing-h3);
	line-height: var(--heading--line-height-h3);
}

.wp-block-heading h4, h4, .h4 {
	font-size: var(--heading--font-size-h4);
	letter-spacing: var(--heading--letter-spacing-h4);
	line-height: var(--heading--line-height-h4);
}

.wp-block-heading h5, h5, .h5 {
	font-size: var(--heading--font-size-h5);
	letter-spacing: var(--heading--letter-spacing-h5);
	line-height: var(--global--line-height-body-h5);
}

.wp-block-heading h6, h6, .h6 {
	font-size: var(--heading--font-size-h6);
	letter-spacing: var(--heading--letter-spacing-h6);
	line-height: var(--global--line-height-body-h6);
}

.wp-block-heading h1, h1, .h1,
.wp-block-heading h2, h2, .h2,
.wp-block-heading h3, h3, .h3,
.wp-block-heading h4, h4, .h4,
.wp-block-heading h5, h5, .h5,
.wp-block-heading h6, h6, .h6 {
	&[style*="--wp--typography--line-height"] {
		line-height: var(--wp--typography--line-height);
	}
}