JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header"><a href="#">Link</a></div>
<div class="target-div"></div>

CSS

.header {
    height:100px;
    background:#ccc;
    width:100%;
}
.target-div {
    width:200px;
    height:200px;
    background:red;
    position:absolute;
    top:0;
    left:200px;
}

JavaScript

var link = $(".header a");
var targetDiv = $(".target-div");
var wWidth = $(window).width();
var wHeight = $(window).height();


link.click(function(e) {
    
    e.preventDefault();
    
    topMargin = wHeight/2 - targetDiv.height()/2;
    
    targetDiv.animate({
        
        top:topMargin + $(".header").height()
        
    })
    
});