JSFiddle - React, Tailwind, and code Playground

JavaScript

$(document).ready(function () {
                    $('body').append("<span><input type='checkbox'></input></span>");
                    $('body').append("<span><input type='submit'></input></span>");
                    $('body').append("<div id='overlay'></div>").css('height','100%');
                    $('#overlay')
                            .addClass('overlay')
                            .css('position','fixed')
                            .css('background-color','silver')
                            .css('z-index','100')
                            .css('top','0px')
                            .css('bottom','0px')
                            .css('left','0px')
                            .css('right','0px')
                            .hide();
                    $('#overlay').append("<div id='box'></div>");                    
                    $('#box')
                            .append("<p>AGUARDE</p>")
                            .addClass('box')
                            .css('position','fixed')
                            .css('line-height','750%')
                            .css('text-align','center')
                            .css('z-index','101')
                            .css('top','40%')
                            .css('bottom','40%')
                            .css('left','40%')
                            .css('right','40%')
                    $('input[type=submit], span input[type=checkbox]').                    
                        click(function (event) {
                            $('#overlay').show();
                        });
                });