JSFiddle - React, Tailwind, and code Playground

CSS

.red {
   color: red;
   font-size: 13px;
}
#div {
    font-size: 18px;
    color: burlywood;
}

JavaScript

document.body.innerHTML = '<div id="div">Element Div 1<span class="red"> - Span Element</span></div>';

// Code for manipulating the created elements
var div = document.getElementById('div');
alert("div.innerHTML => "+div.innerHTML);
var span = document.getElementsByClassName('red')[0];
alert("span.innerHTML => "+span.innerHTML);
alert("div.id => "+div.id);
alert("span.className => "+span.className);