JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
	<div class="curtain">
		<div class="ratio-keeper">
			<div class="wrap hide">
				<div class="video video-frame"></div>
			</div>

			<div class="panel-left"></div>
			<div class="panel-right"></div>

		</div>
	</div>
	<button class="play" type="button" aria-label="Open"></button>
</div>

CSS

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  background: white;
}

.container {
  position: absolute;
  left: 0;
  right: 0;
  min-height: 100%;
  display: flex;
}

.curtain {
  flex: 1 0 0;
  margin: auto;
  max-width: 640px;
  border: 21px solid;
  border-radius: 3.2px;
  border-color: #000 #101010 #000 #101010;
  position: relative;
}

.curtain::before {
  content: '';
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  background: #0a0a0a;
  border: 1px solid;
  border-color: #000 #101010 #000 #101010;
}

.ratio-keeper {
  position: relative;
  height: 0;
  padding-top: 56.25%;
  margin: auto;
  overflow: hidden;
  outline: 1px solid #333;
}

.video-frame {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /*animation: fadeInVideo 0s 0s forwards;
  opacity: 0;*/
}

/*@keyframes fadeInVideo {
  100% {
    opacity: 1;
  }
}*/

iframe {
  user-select: none;
}

.panel-left,
.panel-right {
  position: absolute;
  height: 100%;
  width: 50%;
  top: 0%;
  transition: all 8s ease;
  transition-delay: 300ms;
  /*background-image: url("https://picsum.photos/600");
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;*/
  overflow: hidden;
}

.panel-left {
  left: 0;
  /*background-color: rgb(91, 96, 106);*/
}

.panel-right {
  right: 0;
  /*background-color: rgb(229, 211, 211);*/
}

.panel-left::before,
.panel-right::before {
  content: "";
  position: absolute;
  height: 100%;
  width: 200%;
  top: 0;
  left: 0;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg'> <filter id='filter'> <feTurbulence baseFrequency='0.01 0.0001' numOctaves='5'/> <feColorMatrix values='1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1'/></filter> <rect width='100%' height='100%' filter='url(%23filter)'/> </svg>");
  background-size: cover;
  background-repeat: no-repeat;
  background-position: 0 0;
  pointer-events: none;
}

.panel-right::before {
 ...

JavaScript

const manageCover = (function makeManageCover() {
  const events = {};

  function show(el) {
    el.classList.remove("hide");
  }

  function hide(el) {
    el.classList.add("hide");
  }

  function openCurtain(cover) {
    hide(cover);
    const curtain = document.querySelector(".curtain");
    curtain.classList.add("slide");
    return curtain;
  }

  function showVideo(curtain) {
    const thewrap = curtain.parentElement.querySelector(".wrap");
    show(thewrap);
  }

  function coverClickHandler(evt) {
    const cover = evt.currentTarget;
    const curtain = openCurtain(cover);
    showVideo(curtain);
    cover.dispatchEvent(events.afterClickCover);
  }

  function init(callback) {
    const cover = document.querySelector(".play");
    cover.addEventListener("click", coverClickHandler);
    events.afterClickCover = new Event("afterClickCover");
    cover.addEventListener("afterClickCover", callback);
  }

  return {
    init
  };
}());

const videoPlayer = (function makeVideoPlayer() {
  const config = {};
  const events = {};
  const eventHandlers = {};
  let player = null;


  function loadIframeScript() {
    const tag = document.createElement("script");
    tag.src = "https://www.youtube.com/iframe_api";
    const firstScriptTag = document.getElementsByTagName("script")[0];
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
  }

  function onYouTubeIframeAPIReady() {
    const cover = document.querySelector(".play");
    const wrapper = cover.parentElement;
    const frameContainer = wrapper.querySelector(".video");
    videoPlayer.addPlayer(frameContainer, config.playlist);
  }

  function shufflePlaylist(player) {
    player.setShuffle(true);
    player.playVideoAt(0);
    player.stopVideo();
  }

  function onPlayerReady(event) {
    player = event.target;
    player.setVolume(100);
    shufflePlaylist(player);
    const iframe = player.h;
    iframe.dispatchEvent(events.afterPlayerReady);
  }

  function addPlayer(video, playlist) {

  ...