JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container1 ">
	<div class="curtain1 remove">
		<div class="ratio-keeper">
			<div class="video-one"></div>
			<div class="wrap embed-youtube ">
				<div class="video embed-youtube  " data-id="djV11Xbc914">
				</div>
				<button class="playa cover playgreen  embed-youtube-play" type="button" aria-label="Open"></button>
			</div>
		</div>

		<button class="exit exitpPage2" type="button" aria-label="Open"></button>
		<button class="exit exitpPage3" type="button" aria-label="Open"></button>
	</div>
</div>
<div class="container2 hide">
	<div class="container ">
		<div class="curtain remove">
			<div class="ratio-keeper">
				<div class="video-two"></div>
				<div class="wrap embed-youtube">
					<div class="video embed-youtube" data-id="djV11Xbc914">
					</div>
					<button class="playb cover embed-youtube-play" type="button" aria-label="Open"></button>
				</div>
			</div>
		</div>
		<div class="curtain remove">
			<div class="ratio-keeper">
				<div class="video-three"></div>
				<div class="wrap embed-youtube">
					<div class="video embed-youtube" data-id="djV11Xbc914">
					</div>
					<button class="playc cover embed-youtube-play" type="button" aria-label="Open"></button>
				</div>
			</div>
		</div>
		<div class="curtain remove">
			<div class="ratio-keeper">
				<div class="video-four"></div>
				<div class="wrap embed-youtube">
					<div class="video embed-youtube" data-id="djV11Xbc914">
					</div>
					<button class="playd cover embed-youtube-play" type="button" aria-label="Open"></button>
				</div>
			</div>
		</div>
		<div class="curtain remove">
			<div class="ratio-keeper">
				<div class="video-five"></div>
				<div class="wrap embed-youtube">
					<div class="video embed-youtube" data-id="djV11Xbc914">
					</div>
					<button class="playe cover embed-youtube-play" type="button" aria-label="Open"></button>
				</div>
			</div>
		</div>
		<div class="curtain remove">
			<div class="ratio-keeper">
				<div...

CSS

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

body {
  background: #302b63;
}

.container2 .container {
  background: teal;
}

.container3 .container {
  background: green;
}

.container1 {
  position: absolute;
  left: 0;
  right: 0;
  min-height: 100%;
  min-width: 255px;
  display: flex;
  padding: 8px 8px;
}

.curtain1 {
  flex: 1 0 0;
  margin: auto;
  max-width: 640px;
  border: 21px solid;
  border-radius: 12px;
  border-color: #000 #101010 #000 #101010;
  position: relative;
}

.ratio-keeper {
  position: relative;
  height: 0;
  padding-top: 56.25%;
  margin: auto;
  overflow: hidden;
}

.container {
  position: absolute;
  left: 0;
  right: 0;
  min-height: 100%;
  padding: 8px 8px;
}

.curtain {
  margin: auto auto 40px;
  max-width: 640px;
  border: 21px solid;
  border-radius: 12px;
  border-color: #000 #101010 #000 #101010;
  position: relative;
}

.embed-youtube iframe,
.embed-youtube .embed-youtube-play,
.embed-youtube .embed-youtube-play::before {
  position: absolute;
}

.embed-youtube iframe {
  height: 100%;
  width: 100%;
  top: 0;
  left: 0;
}

.embed-youtube .embed-youtube-play {
  -webkit-appearance: none;
  appearance: none;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  margin: auto;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 90px;
  height: 90px;
  border-radius: 50%;
  cursor: pointer;
  border: 9px solid blue;
  background: transparent;
  filter: drop-shadow(3px 3px 3px #000000b3);
  z-index: 1;
}

.embed-youtube-play::before {
  content: "";
  width: 0;
  height: 0;
  border-top: 20px solid transparent;
  border-bottom: 20px solid transparent;
  border-left: 27px solid blue;
  transform: translateX(4px);
}

.embed-youtube-play:hover {
  box-shadow: 0 0 0 5px rgba(43, 179, 20, 0.5);
}

.embed-youtube-play:focus {
  outline: 0;
  box-shadow: 0 0 0 5px rgba(0, 255, 255, 0.5);
}

.embed-youtube.active .embed-youtube-play {
  display: none;
}

@keyframes rotate {
  0% {
...

JavaScript

/*(function showContainer1() {

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

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

  function exitClickHandler() {
    const thewrap = document.querySelector(".container1");
    show(thewrap);
    const cover = document.querySelector(".container3");
    hide(cover);
  }

  const cover = document.querySelector(".exit");
  cover.addEventListener("click", exitClickHandler);
})();

(function showContainer2() {

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

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

  function exitClickHandler() {
    const thewrap = document.querySelector(".container2");
    show(thewrap);
    const cover = document.querySelector(".container1");
    hide(cover);

  }

  const covers = document.querySelectorAll(".exitPae2");
  covers.forEach(function addCoverListener(cover) {
    cover.addEventListener("click", exitClickHandler);
  });
})();*/



(function showContainer3() {

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

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

  function exitClickHandler() {
    const thewrap = document.querySelector(".container3");
    show(thewrap);
    const cover = document.querySelector(".container1");
    hide(cover);
  }

  const covers = document.querySelectorAll(".exit, .exitPage2");
  covers.forEach(function addCoverListener(cover) {
    cover.addEventListener("click", exitClickHandler);
  });
})();


(function showContainer3() {

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

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

  function exitClickHandler() {
    const thewrap = document.querySelector(".container2");
    show(thewrap);
    const cover = document.querySelector(".container1");
    hide(cover);
  }

  const covers = document.querySelectorAll(".exit, .exitPage3");
  covers.forEach(function addCoverListener(cover) {
    cover.addEventListener("click", exitClickHandler);
 ...