themes-wordpress/assembler/parts/header.html

<!-- wp:group {"metadata":{"name":"Header Container"},"align":"full","style":{"spacing":{"padding":{"top":"0","bottom":"0"},"margin":{"top":"0","bottom":"0"}}},"layout":{"type":"constrained"}} -->
<div class="wp-block-group alignfull" style="margin-top:0;margin-bottom:0;padding-top:0;padding-bottom:0"><!-- wp:spacer {"height":"var:preset|spacing|10","style":{"spacing":{"margin":{"top":"0","bottom":"0"}}}} -->
<div style="margin-top:0;margin-bottom:0;height:var(--wp--preset--spacing--10)" aria-hidden="true" class="wp-block-spacer"></div>
<!-- /wp:spacer -->

<!-- wp:group {"tagName":"header","metadata":{"name":"Contents"},"align":"wide","style":{"spacing":{"margin":{"top":"0","bottom":"0"}}},"layout":{"type":"flex","flexWrap":"nowrap","justifyContent":"space-between"}} -->
<header class="wp-block-group alignwide" style="margin-top:0;margin-bottom:0"><!-- wp:group {"style":{"spacing":{"blockGap":"var:preset|spacing|20"}},"layout":{"type":"flex","flexWrap":"nowrap"}} -->
<div class="wp-block-group"><!-- wp:group {"layout":{"type":"flex","flexWrap":"nowrap"}} -->
<div class="wp-block-group"><!-- wp:site-title /--></div>
<!-- /wp:group --></div>
<!-- /wp:group -->

<!-- wp:group {"style":{"spacing":{"blockGap":"var:preset|spacing|20"}},"layout":{"type":"flex","flexWrap":"nowrap"}} -->
<div class="wp-block-group"><!-- wp:navigation {"className":"order-1 md:order-0"} /-->

<!-- wp:buttons -->
<div class="wp-block-buttons"><!-- wp:button -->
<div class="wp-block-button"><a class="wp-block-button__link wp-element-button">Learn more</a></div>
<!-- /wp:button --></div>
<!-- /wp:buttons --></div>
<!-- /wp:group --></header>
<!-- /wp:group -->

<!-- wp:spacer {"height":"var:preset|spacing|10","style":{"spacing":{"margin":{"top":"0","bottom":"0"}}}} -->
<div style="margin-top:0;margin-bottom:0;height:var(--wp--preset--spacing--10)" aria-hidden="true" class="wp-block-spacer"></div>
<!-- /wp:spacer --></div>
<!-- /wp:group -->