Manually update to https://github.com/lit/lit main

src/test/my-element_test.ts

@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2021 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
 import {MyElement} from '../my-element.js';
 
 import {fixture, html} from '@open-wc/testing';
@@ -48,4 +54,10 @@ suite('my-element', () => {
     `
     );
   });
+
+  test('styling applied', async () => {
+    const el = (await fixture(html`<my-element></my-element>`)) as MyElement;
+    await el.updateComplete;
+    assert.equal(getComputedStyle(el).paddingTop, '16px');
+  });
 });