<html>
<style>
body { color: blue; }
</style>
<body>
<h1>Styles!</h1>
<p>somebody made a very broad selector</p>
<isolated-stuff></isolated-stuff>
</body>
<script>
class DemoElement extends HTMLElement {
constructor() {
super();
this.attachShadow({ mode: 'open' });
this.shadowRoot.innerHTML = `
<style>div { font-size: 24px; }</style> // I can add `color: initial` here 