JSFiddle - React, Tailwind, and code Playground

by cliffeee

HTML

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<h2 class="accordion-toggle">Open Collapsible</h2>
<div id="anyId" class="collapse">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

<h2 class="accordion-toggle">Open Section 1</h2>
<div class="collapse">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

CSS

.accordion-toggle {
  background-color: #777;
  color: white;
  cursor: pointer;
  padding: 18px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 15px;
}

.collapsed, .accordion-toggle:hover {
  background-color: #555;
}

.accordion-toggle:after {
    font-family: 'FontAwesome'; /* essential to enable caret symbol*/
    content: "\f067";
  color: white;
  font-weight: bold;
  float: right;
  margin-left: 5px;
      margin-right: 30px;
}

.collapsed:after {
 content: "\f068";
}

.collapse {
  padding: 0 18px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
  background-color: #f1f1f1;
}

JavaScript

var coll = document.getElementsByClassName("accordion-toggle");
for (var i = 0; i < coll.length; i++) {
  coll[i].addEventListener("click", function(evnt) {
    const currClassList = evnt.target.classList;
    if (currClassList.contains('collapsed')) {
        evnt.target.classList.remove("collapsed");
        var content = evnt.target.nextElementSibling;
        content.style.maxHeight = null;
    } else {
      for (var j = 0; j < coll.length; j++) {
           coll[j].classList.remove("collapsed")
           coll[j].nextElementSibling.style.maxHeight = null;
      }
      this.classList.toggle("collapsed");
      var content = this.nextElementSibling;
      if (content.style.maxHeight){
        content.style.maxHeight = null;
      } else {
        content.style.maxHeight = content.scrollHeight + "px";
      }
    }
  });
}