JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <body>
        <div id='container'>
            <input type="text" id="textbox">
        </div>    
      
    </body>
</html>

CSS

#container {
     display:none;   
}

JavaScript

// Desc: Callback called before object shown using fadeIn()

// jQuery.fx.off = true;

$('#container').fadeIn(500, function() {
    alert('Visible: ' + $(this).is(':visible')  );
});