JSFiddle - React, Tailwind, and code Playground

HTML

<a class="add-comment-btn" href="#">Add Comment</a>         

<div class="inline-comment-form">
<form action="" method="post">
        <div class="textarea">
            <textarea class="inline-comment-textarea" name="comment-textarea"></textarea>
        </div>
        <input value="SUBMIT" name="submit-inline-comment" class="form-btn" type="submit">

    </form>
</div><!--/Inline Comment Form -->

CSS

.inline-comment-form{
    display: none;
}

JavaScript

$(".add-comment-btn").click(function(){
    $(this).next(".inline-comment-form").slideToggle(200).find('input').focus();
    return false;
});