JSFiddle - React, Tailwind, and code Playground

HTML

<div id="tekst1">Hallo Wereld.</div>

CSS

body{
font-family: sans-serif;
}
#tekst1{
    background-color: rgb(255,0,0);
}

JavaScript

var block=document.getElementById("tekst1");
block.innerHTML = "test";
var w=200;
move();

function move()
{
    w=w-1;
    block.style.width=w+'px';
    if(w>30)
        setTimeout(move,40);
}