JSFiddle - React, Tailwind, and code Playground

HTML

<span> one </span>
<span> two </span>
<span> two </span>

CSS

.red
{
    background-color: red;
}

JavaScript

$("span").click(function() {
    $(this).toggleClass("red");
});



var lastBodyHTML = "";
var changes = 0;

function test() {
    if (lastBodyHTML == "") {
        lastBodyHTML = document.body.innerHTML;
    }

    if (lastBodyHTML != document.body.innerHTML) {
        changes++;
        alert("CHANGE #" + changes);
        lastBodyHTML = document.body.innerHTML;
    }
    window.setTimeout(test, 1000);

};

test();