lastsplash (a11n)

Beginning with WordPress v6.3, a Details Block is included in WordPress. This plugin is no longer needed.
The block allows you to easily show and hide content using built-in browser functionality. It doesn’t load any external JavaScript and relies on native HTML functionality. You can configure the appearance using built-in editor controls.
It uses the HTML <code>details</code> element to show and hide the content.

Details: Show and Hide

Adds fallback support for the HTML5 <a href="http://html5doctor.com/the-details-and-summary-elements/" rel="nofollow ugc"><details> and <summary> elements</a> in browsers that don’t support them using <a href="http://mathiasbynens.be/notes/html5-details-jquery" rel="nofollow ugc">Mathias Bynens’ <details>/<summary> jQuery plugin.</a>
Once the plugin is activated on your site, the following HTML should work in all modern browsers, even if they don’t natively support the <details> and <summary> elements:
<pre><code><details>
 <summary>Click for more info...</summary>
 This is where you'd add the additional content that won't be seen until the "summary" is clicked.
</details>
</code></pre>

HTML5 Details Polyfill

Adds fallback support for the HTML5 <details> and <summary> elements in browsers that don't support them.

Details: Show and Hide vs HTML5 Details Polyfill