Use any class for markdown-it-container instead of just a single one.

markdown-it-container-dynamic.js

const markdownItContainer = require('markdown-it-container');
const markdownIt = require('markdown-it');

const md = new markdownIt().use(markdownItContainer, 'dynamic', {
	validate: function () {
		return true;
	},
	render: function (tokens, idx) {
		const token = tokens[idx];
		return token.nesting === 1
			? '<div class="' + token.info.trim() + '">'
			: '</div>';
	},
});

console.log(
	md.render(`
::: my-dynamic-block
Hello, world!
:::`),
);

What happens if you nest blocks? (That is something that I find important – Pandoc supports it.)

What happens if you nest blocks? (That is something that I find important – Pandoc supports it.)

Looks like that works too... kinda:

md.render(`
::: my-dynamic-block
Hello, world!

::: nested-block
Something inside my-dynamic-block!
:::

:::
`);

<div class="my-dynamic-block"><p>Hello, world!</p>
<div class="nested-block"><p>Something inside my-dynamic-block!</p>
</div></div><div class=""></div>

For some reason the closing ::: leaves an extra <div class=""></div> - or in other words, closing the nested block also closes the block it is inside of:

md.render(`
::: my-dynamic-block
Hello, world!

::: nested-block
Something inside my-dynamic-block!
:::
`);

<div class="my-dynamic-block"><p>Hello, world!</p>
<div class="nested-block"><p>Something inside my-dynamic-block!</p>
</div></div>

Got it. Thanks!