JSFiddle - React, Tailwind, and code Playground

HTML

<p>
    <span>lorem ipsum</span>
</p>
<div>Update</div>

CSS

p:before{
    content:"NULL";           
    display:block;
    position:absolute;
    top:77px; /* value = - border-top-width - border-bottom-width */
    /*left:555px; /* controls horizontal position */
    border-width:11px 7px 0px; /* vary these values to change the angle of the vertex */
    border-style:solid;
    border-color:#bce5a5 transparent;
    width:0;
    height:0;
}

JavaScript

$( "div" ).click(function() {
  $('<style>p:before{top:10px}</style>').appendTo('head');
});