JSFiddle - React, Tailwind, and code Playground

by Cthulhu

HTML

<div>1</div>
<div>2</div>
<div id="totil">3</div>
<div>4</div>
<div>5</div>
<div>6</div>
<div>7</div>
<div>8</div>

CSS

div {
  border: 1px solid red;
  height: 200px;
  width: 200px;
}

#totil {
  background-color: red;
  color: white;
}

JavaScript

$(document).scroll(function() {
  var cenas = $(this).scrollTop();
  var elem = $('#totil');
  if (cenas > 200) {
    elem.fadeIn();
  } else {
    elem.fadeOut();
  }
});