kagekiri
Shadow DOM-piercing querySelector/querySelectorAll implementation
css-vars-ponyfill
Client-side support for CSS custom properties (aka "CSS variables") in legacy and modern browsers
get-css-data
A micro-library for collecting stylesheet data from link and style nodes
safe-query
A zero dependency library that provides a thin wrapper around common DOM manipulations to make errors appear sooner.
@depay/react-shadow-dom
A library to easily render react compatible shadow DOMs for web components with individual styling for inside and outside.