JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<div id="container">
     <div id="1">did you know?</div>
     <div id="2">help</div>
     <div id="3">other</div>
</div>

CSS

div { padding: 10px; border: solid 1px #ddd; }

JavaScript

$("#container > div").css({opacity: 0.2 }).hover(function() {
  $(this).stop().animate({ opacity: 1 });
}, function() {
  $(this).stop().animate({ opacity: 0.2 }); 
});