JSFiddle - React, Tailwind, and code Playground

HTML

<nav></nav>

CSS

nav {
    margin:0px auto;
    width:100%;
    height:50px;
    background-color:grey;
    float:left;
    padding:10px;
    border:2px solid red;
    box-shadow: 0 0 0 10px blue inset;
}