JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Click me</li>
    <li>Click me</li>
    <li>Click me</li>
</ul>

JavaScript

$('li').on('click', function(e){
  e.preventDefault();
  if($(this).css('opacity') != 1){
    $(this).fadeTo(300,1);
  }else{
    $(this).fadeTo(300,0.5);
  }
});