JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/leaflet.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://unpkg.com/[email protected]/dist/leaflet.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div id="mapid"></div>

CSS

#mapid {
  min-height: 100vh;
}

h3 {
  margin: 5px 0;
  text-align: center;
}

.leaflet-popup-content {
  margin: 10px;
}

.leaflet-popup-close-button {
  display: none;
}

.leaflet-popup-content-wrapper {
  border-radius: 0;
}

* {
  -webkit-border-radius: 0 !important;
  -moz-border-radius: 0 !important;
  border-radius: 0 !important;
}

hr {
  margin: 10px 0;
}

JavaScript

var map = L.map('mapid').setView([-10, -55], 3);
L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
  attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map);

var tileUrl = "https://storage.googleapis.com/earthenginepartners-hansen/tiles/gfc2015/loss_alpha/{z}/{x}/{y}.png";
L.tileLayer(tileUrl, {
  attribution: 'Hansen/UMD/Google/USGS/NASA'
}).addTo(map);