title: Center two cards in middle of browser window with ReactStrap (Bootstrap4)
body: <p>I'm using reactstrap (based on Bootstrap4) to create a React app. I am trying to create a side-by-side pair of cards (a login and register set) that, when the browser is small, would go one above the other. I can get them centered horizontally, but not vertically. Seems like the container/row/col does not expand to fill the window. How would one go about centering this?</p>
  
  <p>See <a href="https://codesandbox.io/s/71r9x2ynwx" rel="nofollow noreferrer">https://codesandbox.io/s/71r9x2ynwx</a> for a working example.</p>