JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div {
        border-top: 10px solid rgba(255, 255, 255, 0);
        border-right: 70px solid #777;
        border-bottom: 10px solid rgba(255, 255, 255, 0);
        transform: rotate(90deg);
    }