JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<button id="bt_aboutus">bt_aboutus</button>
 
    <div id="page_1"></div>

CSS

#page_1 { position: relative; 
    background-color: yellow;
    border: 2px solid red;
    width: 200px;
    height: 200px;
    margin-top: 300px; }

JavaScript

"use strict";
 
        function getType( Obj ){
            return Object.prototype.toString.call( Obj ).match( /\s([a-zA-Z]+)/ )[ 1 ].toLowerCase();
        }
 
        $( function(){ // forme abrégée de $(document).ready(function(){
 
            var ScreenHeight = "-=200px"; // déplacement relatif de - 200px
 
            $( "#bt_aboutus" ).one( "click", function(){ // one : une seule fois; on : plusieurs fois
                $( "#page_1" ).animate( { "marginTop" : ScreenHeight } , 800, "easeInOutQuad" );
            });
 
        });
 
        $( window ).load( function(){
 
 
        });