import { default } from "https://deno.land/x/postcss@8.4.16/lib/document.d.ts";
Returns a Result instance representing the document’s CSS roots.
const root1 = postcss.parse(css1, { from: 'a.css' })
const root2 = postcss.parse(css2, { from: 'b.css' })
const document = postcss.document()
document.append(root1)
document.append(root2)
const result = document.toResult({ to: 'all.css', map: true })