Portals

createPortal(children, node) becomes <Portal mount={node}>. The prop is mount, not container. It defaults to document.body. Nothing is left at the call site (no wrapper element, no comment), and nothing renders on the server. useShadow puts the content in a shadow root of the mount.

import { Portal } from "@shadow-js/web";

export function Modal(props: { target: HTMLElement }) {
  return (
    <section>
      <Portal mount={props.target}>
        <dialog open>Hello</dialog>
      </Portal>
    </section>
  );
}