JSFiddle - React, Tailwind, and code Playground

HTML

<div id="message-p" style="display:none;background-color: green;color: rgb(255, 255, 255);text-align: center;position: fixed;top: 0px;left: 0px;z-index: 999999;width: 100%;    font-size: 25px; font-style: normal;letter-spacing: 1px;height: 100px;padding-top: 30px;letter-spacing: 1px;">
    Thanks for signig up on our newsletter!    <div id="close_msg" style="position: absolute;top: 0;right: 10px;">
        <a style="color: #c6c6c6;" href="javascript:void(0);" onclick="closemsgF()">X</a>
    </div>
</div>
<script>
    function closemsgF()
    {
        document.getElementById("message-p").style.display = "none";
        document.getElementById("message-n").style.display = "none";
    }

    function openmsgpF()
    {
        document.getElementById("message-p").style.display = "block";
    }

    function openmsgnF()
    {
        document.getElementById("message-n").style.display = "block";
    }
</script>
<script type="text/javascript">openmsgpF();</script>