JSFiddle - React, Tailwind, and code Playground

HTML

<div>Hello Stack Overflow!</div>

CSS

body {
   background: #ccc;   
}

div {
    position: relative;
    background: #fff;
    padding: 10px;
    font-size: 12px;
    text-align: center;
    -webkit-border-radius: 20px;
    -moz-border-radius: 20px;
    border-radius: 20px;
    -webkit-filter: drop-shadow(1px 1px 1px #111) drop-shadow(-1px -1px 1px #111);
}
div:after {
    content: "";
    display: block;
    width: 0;
    height: 0;
    position: absolute;
    left: 50%;
    bottom: -60px;
    margin-left: -15px;
    border-width: 30px 20px 30px 20px;
    border-style: solid;
    border-color: #fff transparent transparent transparent;
}