JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" id="Login" action="validateLogin.jsp">

    <table>
        <tr>
            <td>Enter userID:</td>
            <td><input type="text" name="userid"/></td>
        </tr>

        <tr>
            <td>Enter password:</td>
            <td><input type="password" name="password" /></td>
        </tr>

        <tr>
            <td><br/> <input type="submit" value="Login" /> <input
                type="reset" value="Cancel" /><br /></td>
        </tr>

    </table>

</form>
</html>

CSS

form {
    width: 300px; /* this is needed */
    height: 200px; /* this is needed */
    padding: 10px; /* this is for styling only */
    background: #eee; /* this is for styling only */
    
    position: absolute; /* this is needed */
    margin: auto; /* this is needed */
    left: 0; /* this is needed */
    right: 0; /* this is needed */
    top: 0; /* this is needed */
    bottom: 0; /* this is needed */
}