react/vendor/@reach/portal/examples/basic.example.js

import React from "react";
import Portal from "../src/index";

export let name = "Basic";

export let Example = () => (
  <div
    style={{
      height: 40,
      overflow: "auto"
    }}
  >
    <div style={{ border: "solid 5px", padding: 20, marginLeft: 170 }}>
      This is in the normal react root, with an overflow hidden parent, clips
      the box.
    </div>
    <Portal>
      <div
        style={{
          position: "absolute",
          top: 0,
          left: 20,
          width: 100,
          border: "solid 5px",
          padding: 20,
          background: "#f0f0f0"
        }}
      >
        This is in the portal, rendered in the DOM at the document root so the
        CSS doesn't screw things up, but we render it in the react hierarchy
        where it makes sense.
      </div>
    </Portal>
  </div>
);