JSFiddle - React, Tailwind, and code Playground

HTML

<section class="section show">
  <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>
</section>
<section class="section hide">
  <div class="container2 ">
    <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...

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

const buttons = document.querySelectorAll("button");
const sections = document.querySelectorAll("section");

buttons.forEach((btn) => {
  btn.addEventListener("click", ({ currentTarget }) => {
    const hidden = document.querySelectorAll(".hide");
    hidden.forEach((ele) => {
      ele.classList.remove("hide");
      ele.classList.add("show");
    });
    currentTarget.parentElement.classList.remove("show");
    currentTarget.parentElement.classList.add("hide");
  });
});

const manageCover = (function makeManageCover() {

  function showCover(playButton) {
    const cover = playButton.parentElement;
    cover.classList.add("active");
  }

  function openCurtain(curtain) {
    curtain.classList.add("slide");
  }

  function coverClickHandler(evt) {
    const cover = evt.currentTarget;
    showCover(cover);
    const curtain = evt.currentTarget.parentElement.parentElement.parentElement;
    openCurtain(curtain);
  }

  function addCoverHandler(coverSelector, handler) {
    const cover = document.querySelector(coverSelector);
    cover.addEventListener("click", handler);
  }

  function addClickToButtons(playButtons) {
    playButtons.forEach(function playButtonHandler(playButton) {
      playButton.addEventListener("click", coverClickHandler);
    });
  }

  function init( /*selectors*/) {
    //config.containers = document.querySelector(selectors.container);
    // const allContainers = document.querySelector(".container");
    //const playButtons = document.querySelector(selectors.playButton);
    const allPlaybuttons = document.querySelectorAll(".cover");
    //const allPlaybuttons = document.querySelectorAll(".embed-youtube-play");
    addClickToButtons(allPlaybuttons);
  }


  return {
    addCoverHandler,
    init
  };
}());

const manageUI = (function makeManageUI() {
  document.body.scrollTop = 0;
  const players = [];

  function findPlayers() {
    const allCovers = document.querySelectorAll(".cover");
    const allWrappers =...