title: Why is "ripple effect" from Material-UI not visible when used in Popup (inside Leaflet map)?
body: <p>I'm trying to put <strong>Material-UI</strong> Button inside Popup (<strong>Leaflet</strong> library).
  When I'm doing it outside Popup => everything works fine, each button click triggers <strong>ripple effect</strong>.
  When I'm trying to put the same code inside marker popup, something destroyes (overrides) ripple style and its's no longer visible.</p>
  
  <p>Is it possible to somehow fix this problem?
  Here's my codesandbox: <a href="https://codesandbox.io/s/react-leaflet-ripple-ivsxy" rel="nofollow noreferrer">https://codesandbox.io/s/react-leaflet-ripple-ivsxy</a></p>
  
  <p>I have two buttons here:</p>
  
  <p>(1) Outside the popup - works OK</p>
  
  <p>(2) In the popup (popup is visible after click on marker) - button is visible but ripple effect is broken</p>