newbornfrontender/index.html

## index.html
<!doctype html>

<html>
  <head>
    <!-- Polyfills for Microsoft Edge and Firefox-->
    <script src="https://unpkg.com/@webcomponents/webcomponentsjs@latest/webcomponents-loader.js"></script>
    <title>Test Polymer and Lit Element</title>
  </head>

  <body>
    <script type="module">
      import { LitElement, html } from 'https://unpkg.com/@polymer/lit-element@latest/lit-element.js?module';

      class MyApp extends LitElement {
        static get properties () { return {
          msg: {
            type: String,
          },
        }};

        render () { return html`
          <style>
            span {
              color: blue;
            }
          </style>

          <h1>Hello <span>${this.msg}</span>!</h1>
        `};
      };

      customElements.define('my-app', MyApp);
    </script>

    <my-app msg="world"></my-app>
  </body>
</html>
	<!doctype html>

	<html>
	<head>
	<!-- Polyfills for Microsoft Edge and Firefox-->
	<script src="https://unpkg.com/@webcomponents/webcomponentsjs@latest/webcomponents-loader.js"></script>
	<title>Test Polymer and Lit Element</title>
	</head>

	<body>
	<script type="module">
	import { LitElement, html } from 'https://unpkg.com/@polymer/lit-element@latest/lit-element.js?module';

	class MyApp extends LitElement {
	static get properties () { return {
	msg: {
	type: String,
	},
	}};

	render () { return html`
	<style>
	span {
	color: blue;
	}
	</style>

	<h1>Hello <span>${this.msg}</span>!</h1>
	`};
	};

	customElements.define('my-app', MyApp);
	</script>

	<my-app msg="world"></my-app>
	</body>
	</html>