JSFiddle - React, Tailwind, and code Playground

HTML

<div class="section" id="first">
  
</div>
<div class="wrap section">
    
<span id="circle"></span>
<div class="ok">Hi, my name is Jason</div>
<span id="vertical-divider"></span>
<div class="osk">Hi, my name is Jason</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p><p>&nbsp;</p>
    
</div>

CSS

.section{
  height:100vh;
}
#first{
background:red;
}
.wrap {
width:100%;
position: relative;  
background:gray;
    
}

#circle {
  margin-top:20px;
	-webkit-border-radius: 50%;
	   -moz-border-radius: 50%;
	        border-radius: 50%;
	width: 11px;
	height: 11px; 
	border: 1px solid #F04948;
	position: absolute;
	top: 0;
	left: 50%;
	margin-left: -6px;
}
.ok{
margin:0 auto;
text-align:center;
}
#vertical-divider {
  max-height:500px;
  margin-top:20px;
	width: 2px;
    height: 50px;
	position: absolute;
	left: 50%;
	top: 12px;
	border-left: 3px solid black;
}

JavaScript

$(document).on('scroll', function(e) {
   var hT = $('#vertical-divider').offset().top,
       hH = $('#vertical-divider').outerHeight(),
       wH = $(window).height(),
       wS = $(this).scrollTop(),
       topofBox
    console.log((hT-wH) , wS);
      
    $('#vertical-divider').css('height', '' + (document.body.scrollTop - 300) + 'px');
});