JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#">Test</a>

CSS

a{
	float: left;
	height: 35px;
	position:relative;	
	border: 1px solid red;
	border-right: none;	
    width: 100px;
} 
	
a:before{
	content: "";
	position: absolute;
	top: -1px;
	right: -18px;
	width: 0;
	height: 0;
	border-color: white white white red;
	border-style: solid;
	border-width: 19px 0 18px 18px;	
	}