async function polyfill() { const { hydrateShadowRoots } = await import( '@webcomponents/template-shadowroot/template-shadowroot.js' ); window.addEventListener('DOMContentLoaded', () => hydrateShadowRoots(document.body), { once: true, }); } const polyfillCheckEl = new DOMParser() .parseFromString( `

`, 'text/html', { includeShadowRoots: true, } ) .querySelector('p'); if (!polyfillCheckEl?.shadowRoot) { polyfill(); }