JSFiddle - React, Tailwind, and code Playground

HTML

<div id="admin">
    
    <p class='adminToggle'><br />Admin</p>
    
    <form id="adminForm" method="POST" action="loginAdmin.php">
        Username:<br /><input type="text" name="username"/><br />
        Password:<br /><input type="password" name="password"/><br />
        <div id="button">
            <button id="btn" name="send" type="submit" value="enviar">Login</button>
        </div>
        
    </form>
</div>

CSS

#admin {
	position: absolute;
	margin-top: 350px;
	right: 0%;
	width: 224px;
	z-index: 1;
	height: 140px;
}
#admin p {
	font-family: Lato-Light;
	float: right;
	cursor: pointer;
	color: blue;
	bottom: 0;
	right: 0;
	position: absolute;
}
#admin form {
	display: none;
	font-family:Lato-Regular;
	font-size: 14px;
	margin:30px 0 0 100px;
}
#admin input {
	width: 120px;
}

JavaScript

$(document).ready(function() {
    $('#admin > .adminToggle').click(function(){
        var _open = $(this).hasClass("open");
            $('#adminForm').stop(true).slideToggle();
            $(this).stop(true,false).animate({
                right:_open ? 0 : 140
            }).toggleClass("open");
     });
});