JSFiddle - React, Tailwind, and code Playground

HTML

<head></head>

<body>

  <div id="megaAll">

    <div id="megaMain">
      <div id="headerContainer">
        <div id="header">
          <h1>Starspace</h1></div>
      </div>
      <div id="contentContainer">
        <div id="content">
          Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer pulvinar, ligula vel maximus condimentum, enim purus tristique odio, vitae sodales sapien leo id sem. Phasellus ante risus, ullamcorper vitae tortor vel, scelerisque aliquet sem. Nam eget neque tincidunt, finibus urna a, efficitur risus. Etiam ac arcu elit. Nunc vitae hendrerit lectus. Vivamus gravida tincidunt lacinia. Nulla at velit ut enim convallis gravida. Duis ornare turpis et ante sodales laoreet. Aenean eu ipsum a nisl auctor luctus. Praesent porttitor dolor at eros cursus malesuada bibendum nec metus. Donec consequat finibus sem sed consectetur. Nullam tempor sagittis vulputate. Aliquam laoreet leo in enim hendrerit, vitae pharetra elit aliquam.<br><br>

Nulla eu odio eget mi dapibus suscipit vel in lacus. Praesent blandit rhoncus imperdiet. Integer consequat efficitur nibh, in dapibus odio aliquam ut. Nullam sed consequat tortor. Fusce leo velit, pellentesque nec erat non, viverra fringilla metus. Pellentesque et lorem risus. Nullam in urna in erat porta finibus eu ac sapien. Nam nec varius lorem. Morbi at libero nec libero blandit pulvinar. Nunc ut nulla sit amet urna pellentesque viverra sed quis velit. Interdum et malesuada fames ac ante ipsum primis in faucibus. Maecenas augue enim, volutpat at hendrerit quis, volutpat in dolor. Etiam dignissim nisi et tellus pulvinar dapibus. Pellentesque finibus vel nulla a maximus.<br><br>
          
          <img src="https://45.media.tumblr.com/5d9d44687164a666bb7e344054a9901d/tumblr_n6kpgvrs7x1skcd7fo1_500.gif"><br><br>
               
In vitae leo dolor. Aliquam in diam diam. Vestibulum ullamcorper, nibh vel rutrum rhoncus, tortor magna ornare orci, et aliquet tortor massa eu nibh. Sed convallis,...

CSS

body{
  box-sizing: border-box;
  background-color: white;
  text-align: center;
  height: 100%;
  font-family: "Courier New";
}

#megaAll{
  box-sizing: border-box;
  paosition: absolute;
  background-color: gray;
  top: 0px;
  bottom: 0px;
  left: 0px;
  right: 0px;
}

#megaMain{
  box-sizing: border-box;
  position: absolute;
  background-color: pink;
  top: 0px;
  bottom: 0px;
  left: 0px;
  right: 50px;
}

#headerContainer{
  box-sizing: border-box;
  position: absolute;
  background-color: lightblue;
  height: 100px;
  top: 0px;
  left: 0px;
  right: 0px;
}

#contentContainer{
  box-sizing: border-box;
  position: absolute;
  background-color: lightyellow;
  top: 100px;
  left: 0px;
  right: 0px;
  bottom: 0px;
  padding: 20px;
}

#megaSidebar{
  box-sizing: border-box;
  position: fixed;
  background-color: brown;
  width: 50px;
  height: 100%;
  top: 0px;
  bottom: 0px;
  right: 0px;
}