JSFiddle - React, Tailwind, and code Playground
by kiokotzu
HTML
<div class="luis"></div>
<div class="hola"></div>
CSS
.luis{height:100px; background:red;}
.hola{height:200px; margin:1000px 0 0 0; background:blue;}
JavaScript
$(window).scroll(function(event){
var restar = $(this).height() - $('.hola').outerHeight()/2;
var alto_total = $(this).scrollTop();
var loader_business = $('.hola').offset().top - restar;
console.log(alto_total + " == " + loader_business +'resta'+ restar);
if(alto_total >= loader_business)
alert('tomalo');
});