JSFiddle - React, Tailwind, and code Playground

HTML

<nav class="fixed">Navigation</nav>

<header>Header</header>

<nav>Navigation</nav>

<aside>Left sidebar</aside>

<article>
    <p>Lorem ipsum dolor</p>
    <p>Lorem ipsum dolor</p>
    <p>Lorem ipsum dolor</p>
    <p>Lorem ipsum dolor</p>
    <p>Lorem ipsum dolor</p>
    <p>Lorem ipsum dolor</p>
</article>

CSS

body, html {
    padding: 0;
    height: 100%;
}
article {
    background-color: yellow;
    height: 1200px;
    padding-left: 210px;
}
header {
    display: block;
    width: 100%;
    height: 30px;
    position: relative;
    background-color: red;
    z-index: 2;
}

aside {
    height: 100%;
    width: 200px;
    padding-top: 50px;
    background-color: orange;
    position: fixed;
    top: 0;
}