themes-wordpress/shhh/templates/404.html

<!-- wp:template-part {"slug":"header","tagName":"header"} /-->

<!-- wp:group {"tagName":"main","layout":{"type":"constrained"}} -->
<main class="wp-block-group">
	<!-- wp:pattern {"slug":"shhh/404"} /-->

	<!-- wp:spacer {"height":"4rem"} -->
	<div style="height:4rem" aria-hidden="true" class="wp-block-spacer"></div>
	<!-- /wp:spacer -->
</main>
<!-- /wp:group -->

<!-- wp:template-part {"slug":"footer","tagName":"footer"} /-->