JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="zh-tw">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <input type="button" class="button" value="留言">
    <div class="text active">
        <textarea name="area" cols="30" rows="10"></textarea>
        <input type="submit" value="send it">
    </div>
    
</body>
</html>

CSS

.text{
    opacity: 0;
    transition: all 3s;
}
.text.active{
    opacity:1;
}

JavaScript

$(document).ready(function () {
    $('.button').click(function () { 
        $('.text').toggleClass('active');
        
    });
});