JSFiddle - React, Tailwind, and code Playground

HTML

<nav>Side Nav</nav>
<header>Header</header>
<main> 
 <h1>Main Content</h1>
 <div class="wideContainer">
   Some wide and tall container
 </div>
</main>

CSS

body {
  padding: 0;
  margin: 0;
}
nav {
  position: fixed;
  width: 150px;
  background-color: gray;
  height: 100vh;
}
header {
  height: 100px;
  background-color: silver;
  padding-left: 150px;
}
main {
  padding-left: 150px;
}
.wideContainer {
  width: 2000px;
  height: 1000px;
  background-color: turquoise;
}