JSFiddle - React, Tailwind, and code Playground

HTML

<div class="keepincenter"></div>

CSS

.keepincenter{
    position:absolute;
    width:100px;
    height:50px;
    background-color:#ffe400;
}

JavaScript

function keep_div_centered(){
    window_height = $(window).height();
    window_width = $(window).width();
    obj_height = $('.keepincenter').height();
    obj_width = $('.keepincenter').width();
    $('.keepincenter').css('top',(window_height/2)-(obj_height/2)).css('left',(window_width/2)-(obj_width/2))
}
keep_div_centered();
$(window).resize(function(){
    keep_div_centered();
})