A hero is a large area above the fold, typically an image, video, or call to action.
Start by creating a block type called Hero.
It has a body field by default, add a media field that can reference image, video, and remote video.
Add a hero region to the theme info file.
regions:
hero: Hero
Add the hero region to the page template, inside our above the fold area.
{% embed 'unocss_starter_demo:layout_top' %}
{% block top %}
<header role="banner">
{{ include('unocss_starter_demo:header', {
branding: page.header,
secondary_menu: page.secondary_menu,
primary_menu: page.primary_menu
}) }}
</header>
{{ page.hero }}
{{ page.breadcrumb }}
{{ page.highlighted }}
{{ page.help }}
{% endblock %}
{% endembed %}
Clear the cache and create a new hero block in this region. This example uses a youtube video.

It's working, but the hero block display needs to be configured.
The remote video uses oEmbed, and additional libraries are loaded from the media module.
https://git.drupalcode.org/project/drupal/-/blob/11.x/core/modules/media/media.libraries.yml#L15
These libraries are attached in different places, but when a youtube video is use as remote video media, both are applied to the embedded iframe.
<iframe class="media-oembed-content">
/* core/oembed.formatter */
.media-oembed-content {
max-width: 100%;
border: none;
background-color: transparent;
}
/* core/oembed.frame */
iframe {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
margin: 0;
}
To get the video to fill the area, a little extra css is needed.
.media-oembed-content {
@apply aspect-video w-full h-auto;
}
Here it is after configuring and styling.