JSFiddle - React, Tailwind, and code Playground

by ten1seven

HTML

<div class="nav"></div>
<div class="nav__shadow"></div>

CSS

body,
html {
    background-color: #1a83a1;
    margin: 0;
    padding: 0;
}

.nav {
    background-color: #3f3f3f;
    height: 54px;
    left: 50%;
    margin-left: -170px;
    position: absolute;
    top: 0;
    width: 340px;
    z-index: 2;
}

.nav__shadow:after {
    background-color: pink;
    border-radius: 100%;
    box-shadow: 0 0 50px rgba(0, 0, 0, 1);
    content: '';
    display: block;
    height: 50px;
    left: 50%;
    margin-left: -150px;
    position: absolute;
    top: 0px;
    width: 300px;
    z-index: 1;
}