JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mydiv"></div>
<button id="startTimeout">restart</button>

CSS

#mydiv{
    width: 100px;
    height: 100px;
    background: white;
    text-align: center;
    display: table-cell;
    vertical-align: middle;
}

JavaScript

var btn = document.getElementById("startTimeout");
btn.onclick = function(){
    var mydiv = document.getElementById("mydiv")   ;
    mydiv.innerHTML = "START";
    mydiv.style.background = "green";
    setTimeout(function(){
        mydiv.innerHTML = "STOP";
        mydiv.style.background = "red";
    }, 2000);
}