themes-wordpress/portia/templates/404.html

<!-- wp:group {"align":"full","style":{"position":{"type":"sticky","top":"0px"}},"layout":{"type":"default"}} -->
<div class="wp-block-group alignfull">
	<!-- wp:template-part {"slug":"header","tagName":"header"} /-->
</div>
<!-- /wp:group -->

<!-- wp:group {"tagName":"main","style":{"spacing":{"margin":{"top":"0px","bottom":"0px"},"padding":{"top":"var:preset|spacing|80","bottom":"var:preset|spacing|80"}}},"layout":{"type":"constrained"}} -->
<main class="wp-block-group" style="margin-top:0px;margin-bottom:0px;padding-top:var(--wp--preset--spacing--80);padding-bottom:var(--wp--preset--spacing--80)">
	<!-- wp:pattern {"slug":"portia/hidden-404"} /-->
	<!-- wp:pattern {"slug":"portia/hidden-search-field"} /-->
</main>
<!-- /wp:group -->

<!-- wp:group {"align":"full","style":{"spacing":{"margin":{"top":"0","bottom":"0"}}},"layout":{"type":"constrained"}} -->
<div class="wp-block-group alignfull" style="margin-top:0;margin-bottom:0">
	<!-- wp:template-part {"slug":"footer","tagName":"footer","align":"full"} /-->
</div>
<!-- /wp:group -->