I'm on Chrome 63.0.3239.132, building a SPA in Polymer 2.0.
Since Polymer is encapsulating CSS of the shadow-dom and there are several components which don't override the user agent style sheet, it appears that i can't override the components children styled by the user agent sheet if they don't offer a mixin.
e.g: The vaadin-grid component (https://www.webcomponents.org/element/vaadin/vaadin-grid) has a div#table in the shadow-tree which doesn't provide a div:focus, so the user agent style sheet adds a blue outline.
<vaadin-grid>
...
#shadow-root
<vaadin-grid-table>
...
#shadow-root
<div id="table">
<!-- user agent adds a div:focus {outline: -webkit-focus ring-color auto 5px;} -->
</div>
</vaadin-grid-table>
</vaadin-grid>
How do i remove/override this?