JSFiddle - React, Tailwind, and code Playground

HTML

<div>&nbsp;</div>

CSS

div {
    width:0px;
    height:0px;
    border-left:solid 100px rgba(0,0,0,0);
    border-top:solid 10px  rgba(0,0,0,0);
    border-right:solid 100px blue;
    border-bottom:solid 10px blue;
}