JSFiddle - React, Tailwind, and code Playground

HTML

<p id='char-count'></p>
<div id="text-area" contenteditable="true"></div>

CSS

#text-area {
  width: 100%;
  max-height: 100px;
  min-height: 50px;
  overflow: auto;
  border: 1px solid #999;
}

JavaScript

maxCharacters = 140;

$('#char-count').text(maxCharacters);

$('#text-area').bind('keyup keydown', function() {
  var count = $('#char-count');
  var characters = $(this).text().length;
  if (characters > (maxCharacters - 11)) {
    count.addClass('over');
  } else {
    count.removeClass('over');
  }
  count.text(maxCharacters - characters);
});