JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&amp;sensor=false"></script>
    <script>
// This example displays a marker at the center of Australia.
// When the user clicks the marker, an info window opens.

function initialize() {
  var myLatlng = new google.maps.LatLng(-25.363882,131.044922);
  var mapOptions = {
    zoom: 4,
    center: myLatlng
  };

  var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);

  var contentString = '<div id="content">'+
      '<div id="siteNotice">'+
      '</div>'+
      '<h1 id="firstHeading" class="firstHeading">Video in Info Window</h1>'+
      '<div id="bodyContent">'+
      '<iframe width="640" height="390" src="//www.youtube.com/embed/a8UOzBUZxCw" frameborder="0" allowfullscreen></iframe>'+
      '</div>'+
      '</div>';

  var infowindow = new google.maps.InfoWindow({
      content: contentString
  });

  var marker = new google.maps.Marker({
      position: myLatlng,
      map: map,
      title: 'Uluru (Ayers Rock)',
  });
  google.maps.event.addListener(marker, 'click', function() {
    infowindow.open(map,marker);
  });
}

google.maps.event.addDomListener(window, 'load', initialize);

    </script>

  <body>
    <div id="map-canvas"></div>
  </body>

CSS

html, body, #map-canvas {
        height: 100%;
        margin: 0px;
        padding: 0px
      }