JSFiddle - React, Tailwind, and code Playground

HTML

<div class="foo" />

CSS

div {
    border-style: solid;
    border-width: 30px;
    border-color: rgba(255,255,255,0) rgba(255,255,255,0) rgba(255,255,255,0) #eee 
}

body {
    padding: 20px;
}