index.html

<!doctype html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta
            name="viewport"
            content="width=device-width, initial-scale=1.0" />
        <title>Quantum</title>
    </head>
    <body>
        <div id="app"></div>
        <script type="module">
            import { render } from 'preact';
            import { useEffect, useRef } from 'preact/hooks';
            import { html, render as uRender } from 'uhtml';
            import { attachRealm } from './src/index.js';

            const root = document.getElementById('app');
            const realm = attachRealm(root);
            realm.observe(() => {
                uRender(
                    realm.root,
                    html`<strong>${realm.childNodes.length ? realm.childNodes : 'Default content'}</strong>`
                );
            });

            render('Hello World', root);
            setTimeout(() => {
                render('Hi there', root);
                setTimeout(() => {
                    render(null, root);
                }, 2000);
            }, 2000);
        </script>
    </body>
</html>