JSFiddle - React, Tailwind, and code Playground

HTML

<form id="form1" runat="server">
    <div id="main">
        <h1>ITPS Real Time Monitoring</h1>
        <!-- Div for flot graph -->
        <div id="chart-container">
            <div id="placeholder" style="width: 600px; height: 220px;" /></div>
            <div id="placeholder2"></div>
        </div>
    </div>
    <div id="blocker">
        <img id="introImage" src="Images/Untitled.png" alt="some_text" />
        <input id="btnEnter" type="button" value="Enter" onclick="loadMainMenu();" />
    </div>
</form>

JavaScript

$(document).ready(function () {
    $("#main").hide();
    $("#blocker").hide();
});
$(window).load(function () {
    $("#blocker").fadeIn(2000);
});

    function loadMainMenu() {
        debugger;
        $("#blocker").hide();
        $("#btnEnter").hide();
        $("#main").show();
    }