Example of a bug in Polymer 2 style modules

polymer-style-module-bug.html

<dom-module id="foo-element">
	<template strip-whitespace>
		<style>
			:host {
				display: inline-block;
			}
		</style>
		<button>foo</button>
	</template>
	<script>
		Polymer({
			is: 'foo-element'
		});
	</script>
</dom-module>
<dom-module id="foo-module">
	<template>
		<style>
			.foo {
				background-color: red;
			}
		</style>
	</template>
</dom-module>