JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo">123456789</div>

JavaScript

var x = document.getElementById("foo");
var y = document.getElementById("foo").innerHTML;
x.innerHTML = "";

for(var i=0;i<y.length;i++){

var node = document.createElement("span");
node.setAttribute("id", 'foo_'+(i+1));
node.setAttribute("style", 'font-size:'+(i*4+12)+'px');
var textNode = document.createTextNode(y.charAt(i));
node.appendChild(textNode);
x.appendChild(node);

}