JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdn.rawgit.com/mrdoob/three.js/master/build/three.min.js"></script>

CSS

body {
	  margin: 0;
}

JavaScript

var camera, scene, renderer;

init();
animate();

function init() {

   	camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 1000 );
    camera.position.set( 2, 2, - 2 );
    camera.lookAt( 0, 0.5, 0 );
    
    scene = new THREE.Scene();
    
    var hemiLight = new THREE.HemisphereLight( 0xffffff, 0x444444 );
    hemiLight.position.set( 0, 20, 0 );
    scene.add( hemiLight );
    
    var dirLight = new THREE.DirectionalLight( 0xffffff );
    dirLight.position.set( - 3, 10, - 10 );
    dirLight.castShadow = true;
    dirLight.shadow.camera.top = 2;
    dirLight.shadow.camera.bottom = - 2;
    dirLight.shadow.camera.left = - 2;
    dirLight.shadow.camera.right = 2;
    dirLight.shadow.camera.near = 0.1;
    dirLight.shadow.camera.far = 40;
    scene.add( dirLight );
    
    var ground = new THREE.Mesh( new THREE.PlaneBufferGeometry( 100, 100 ), new THREE.MeshPhongMaterial( { color: 0x999999, depthWrite: false } ) );
    ground.rotation.x = - Math.PI / 2;
    ground.receiveShadow = true;
    scene.add( ground );
    
    var boxGeometry  = new THREE.BoxBufferGeometry();
    var boxMaterial = new THREE.MeshStandardMaterial();

    mesh = new THREE.Mesh( boxGeometry, boxMaterial );
    mesh.position.y = 0.5;
    mesh.castShadow = true;
    scene.add( mesh );
    
    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.gammaOutput = true;
    renderer.gammaFactor = 2.2;
    renderer.shadowMap.enabled = true; // set to "false": no warning
    document.body.appendChild( renderer.domElement );
    
  }

function animate() {

    requestAnimationFrame( animate );
    renderer.render( scene, camera );

}