JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <head>  
    <script>
function hide(obj) {
  obj.style.opacity = obj.style.opacity*1 - 0.1;
  if (obj.style.opacity > 0) setTimeout(function() {hide(obj)}, 10);
  }
  
function show(obj) {
  obj.style.opacity = obj.style.opacity*1 + 0.1;
  if (obj.style.opacity <= 1) setTimeout(function() {show(obj)}, 10);
  }
  
    </script>
  </head>
  <body>
    <img id="pict" style="opacity: 1;" src="http://www.google.com.ua/images/nav_logo99.png" alt="" onmouseover="hide(this)" onmouseout="show(this)">
  </body>
</html>