JSFiddle - React, Tailwind, and code Playground

CSS

div{ border: 10px solid red; width: 3;}
div:before,
div:after{ content: "some more content"; }

JavaScript

var d = document.createElement('div');
d.innerHTML = "hello, world!";
d.setAttribute('style', "font: 100px/1em sans-serif;");

document.body.appendChild(d);

alert(d.clientHeight);