Shadow root : The root node of the shadow tree. Tweets will appear faster and pages will scroll more smoothly, even when displaying multiple Tweets on the … As such, the browser will override my custom CSS properties with the "more specific" ones provided by the component itself. Because this is a newer API, you might first want to check that Shadow Parts are supported by the browsers you intend to target: browser support (both Chrome for Android and iOS Safari support the API). Of course, like on this example, the style used in the Shadow DOM must define which variables it wants to use and where, but this is an easy way of providing customization on key points. So I guess the only way to do this for non-inheritable properties is by either injecting CSS via the template (e.g. There are a few exceptions that inherit from the parent document, like font family and document font sizes (e.g. CSS custom properties pierce through shadow DOM. About a year ago, Twitter announced it would start displaying embedded tweets with the shadow DOM rather than an