JSFiddle - React, Tailwind, and code Playground
by dusset
HTML
<div id="longbox"><div id="cloud1" style="width:35%"></div></div>
CSS
#longbox { width:100%; height: 2000px; background: #666; }
#cloud1 { height:200px; background: red; position:absolute; left: 10%; }
JavaScript
$(window).scroll(function () {
var currentScroll = $(window).scrollTop();
var h = $(window).height();
percentScroll = 1 - currentScroll/h
$("#cloud1").css('left', 0);
if (35*percentScroll < 1){
$("#cloud1").css('left', (35*percentScroll)+'%');
}else{
$("#cloud1").css('left', (35*percentScroll)+'%');
}