deep-focus-trap/src/focus-trap.umd.js

A focus trap library that pierces that shadow dom. So you can use it with native web components. Deep Focus Trap is a lightweight library written in vanilla js with only one dependency (that is tree-shakable if not in use).

import { focusTrap } from './focus-trap'

export default function (config) {
  return new focusTrap(config)
}