The README doesn't include any information about how to apply styles to these components. For Polymer, I would do something like this:

<iron-icon class="big" src="big_star.png"></iron-icon>

<style is="custom-style">
  .big {
    --iron-icon-height: 32px;
    --iron-icon-width: 32px;
  }
</style>

This tutorial covers the basics of not having conflicting styles, but it leaves out the part about wanting to change the styling of web components in your application.

Do these basic-web-components not allow any kind of styling at all?
Or am I just missing something here?