Is it possible to extract the scoped styles of a Vue app and pass them to https://github.com/karol-f/vue-custom-element? I see some options here http://vuejs.github.io/rollup-plugin-vue/#/en/2.3/?id=custom-handler but could not figure out how to pass it to this:

Vue.use(vueCustomElement)
Vue.customElement('my-component', MyComponent, {
  shadow: true,
  shadowCSS: `h1{color: blue}`
})

Related karol-f/vue-custom-element#17. Bonus info:, our styles are currently written as <style scoped> inside each .Vue component.