JSFiddle - React, Tailwind, and code Playground

HTML

<div class="comment">
Comment 1
</div>
<div class="comment">
Comment 2
</div>
<div class="comment">
Comment 3
</div>
<div class="comment">
Comment 4
</div>
<div class="comment">
Comment 5
</div>

CSS

.comment {
  width: 50%;
  height: 50px;
  margin-top: 20px;
  padding: 10px;
  background-color: green;
  color: white;
  border-radius: 10px;
  transition: width 1s;
}

.comment.activeComment {width: 100%;}

JavaScript

$('.comment').on('click', function() {
	$('.activeComment').removeClass('activeComment');
  $(this).addClass('activeComment');
});