JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
  <div class="container with-curtain">
    <button class="playa thePlay" type="button" aria-label="Open" pointer-events="none">
      <svg width="100%" height="100%" viewBox="0 0 64 64">
        <g id="play">
          <title>Play</title>
          <circle cx="32" cy="32" r="32" fill="transparent" pointer-events="visiblePainted" />
          <path d="M25.6,46.4L44.8,32L25.6,17.6V46.4z M32,0C14.3,0,0,14.3,0,32s14.3,32,32,32s32-14.3,32-32S49.7,0,32,0z
                  M32,57.6C17.9,57.6,6.4,46.1,6.4,32S17.9,6.4,32,6.4S57.6,17.9,57.6,32S46.1,57.6,32,57.6z" />
        </g>
      </svg>
    </button>
    <div class="inner-container curtain curtain1">
      <div class="ratio-keeper">
        <div class="wrapa">
          <div class="video video-frame" data-id="CHahce95B1g"></div>
        </div>
        <div class="panel-left"></div>
        <div class="panel-right"></div>
      </div>

      <button class="home" type="button" aria-label="Close">
        <svg class="homesvg" width="38.39" height="38.39" viewBox="0 0 100 100">
          <g id="home">
            <title>Home</title>

            <path d="M 6.3895625,6.4195626 C 93.580437,93.610437 93.580437,93.610437 93.580437,93.610437" />
            <path d="M 6.3894001,93.6106 C 93.830213,6.4194003 93.830213,6.4194003 93.830213,6.4194003" />
          </g>
        </svg>
      </button>
    </div>
  </div>
  <div class="container with-curtain">
    <button class="playb thePlay" type="button" aria-label="Open">
      <svg width="100%" height="100%" viewBox="0 0 64 64">
        <use href="#play" />
      </svg>
    </button>
    <div class="inner-container curtain curtain2">
      <div class="ratio-keeper">
        <div class="wrapa">
          <div class="video video-frame"></div>
        </div>
        <div class="panel-left"></div>
        <div class="panel-right"></div>
      </div>
      <button class="home" type="button" aria-label="Close">
        <svg class="homesvg" width="38.39"...

CSS

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

body {
  background: #353198;
  animation: fade 2s ease 0s forwards;
}


@keyframes fade {
  0% {
    opacity: 0;
  }

  100% {
    opacity: 1;
  }
}

.outer {
  display: flex;
  min-height: 100%;
  box-sizing: border-box;
  justify-content: center;
}

.container {
  display: flex;
  justify-content: center;
  position: relative;
  z-index: 2;
}

.container.active {
  flex: 1 0 0;
}

body.bg1{
  animation: fadebody 5s ease 0s forwards;
}
body.bg1:after {
  content: "";
  position: fixed;
  z-index: 1;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-size: 165px 165px;
  background-image: linear-gradient(teal 5px, #0000 5px),
    linear-gradient(90deg, teal 5px, #0000 5px),
    linear-gradient(black 10px, #0000 10px 160px, black 160px),
    linear-gradient(90deg, black 10px, #0000 10px 160px, black 160px),
    linear-gradient(orange 15px, #0000 15px 155px, orange 155px),
    linear-gradient(90deg, orange 15px, #0000 15px 155px, orange 155px),
    linear-gradient(black 20px, #0000 20px 150px, black 150px),
    linear-gradient(90deg, black 20px, #0000 20px 150px, black 150px),
    linear-gradient(teal 25px, #0000 25px 145px, teal 145px),
    linear-gradient(90deg, teal 25px, #0000 25px 145px, teal 145px),
    linear-gradient(black 30px, #0000 30px 140px, black 140px),
    linear-gradient(90deg, black 30px, #0000 30px 140px, black 140px),
    linear-gradient(orange 35px, #0000 35px 135px, orange 135px),
    linear-gradient(90deg, orange 35px, #0000 35px 135px, orange 135px),
    linear-gradient(black 40px, #0000 40px 130px, black 130px),
    linear-gradient(90deg, black 40px, #0000 40px 130px, black 130px),
    linear-gradient(teal 45px, #0000 45px 125px, teal 125px),
    linear-gradient(90deg, teal 45px, #0000 45px 125px, teal 125px),
    linear-gradient(black 50px, #0000 50px 120px, black 120px),
    linear-gradient(90deg, black 50px, #0000 50px 120px, black 120px),
    linear-gradient(orange...

JavaScript

const manageUI = (function makeManageUI() {

  function showBody() {
    const theBody = document.querySelector("body");
    theBody.classList.remove("bg1");
  }

  function showActive() {
    const theActive = document.querySelector(".with-curtain.active");
    theActive.classList.remove("active");

  }

  function showHidden() {
    const theHides = document.querySelectorAll(".hide");
    theHides.forEach(function(removeHide) {
      removeHide.classList.remove("hide");
    });

  }

  function homeClickHandler() {
    showBody();
    showActive();
    showHidden();
  }

  function addClickToHome(goHome) {
    goHome.forEach(function addEventHandler(goHome) {
      goHome.addEventListener("click", homeClickHandler);
    });
  }

  function init() {
    const goHome = document.querySelectorAll(".home");
    addClickToHome(goHome);
  }

  return {
    init
  };
}());

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

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

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

  function hideAll(elements) {
    elements.forEach(hide);
  }

  function showBody() {
    const theBody = document.querySelector("body");
    theBody.classList.add("bg1");
  }

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

  function coverClickHandler(evt) {
    hideAll(config.containers);
    const cover = evt.currentTarget;
    showCovers(cover);
    showBody();
  }

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

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

  function init(selectors) {
    config.containers = document.querySelectorAll(selectors.container);
    const...