JSFiddle - React, Tailwind, and code Playground

HTML

<nav>Menú</nav>
<header>
    Lorem Ipsum
</header>
<footer>
    Pies
</footer>

CSS

*{
    margin:0;
}
nav{
    position:fixed;
    left;0;
    background-color:#f00;
}
header{
    width:100%;
    height:140vh;
    background-color:#333;
    text-align:center;
    color:#fff;
}
footer{
    width:100%;
    height:140vh;
    background-color:#800;
    text-align:center;
    color:#fff;
}