JSFiddle - React, Tailwind, and code Playground
HTML
<div id="abs"></div>sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br /><span id="trigger">0</span>sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f<br />sdfjkh sdfjks f
CSS
#abs{
position:fixed;
top:10px;
left:10px;
border:1px solid red;
background-color:#fff;
font-weight:bold;
width:100px;
height:30px;
color:black;
overflow:hidden;
}
#trigger{
color:red;
font-weight:bold;
}
JavaScript
$(window).scroll(function(){
$window = $(window);
var visibleTop = $window.scrollTop();
var visibleBottom = visibleTop + $window.height();
var elementTop = $('#trigger').offset().top;
if ( elementTop > visibleTop && elementTop < visibleBottom)
$('#abs').text('visible')
else
$('#abs').text('');
});