JSFiddle - React, Tailwind, and code Playground

HTML

<div id="dv" style ="transition-property: transform; transform-origin: 0px 0px 0px; transform: translate(0px, -13361.5px) scale(1) translateZ(42px);"></div>
<div id="result"></div>

JavaScript

var dv = document.getElementById('dv');
var dvStyle = dv.getAttribute('style');

var transZRegex = /\.*translateZ\((.*)px\)/i;
var zTrans = transZRegex.exec(dvStyle)[1];

document.getElementById('result').innerHTML = zTrans.toString();