JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test removeMe"></div>

CSS

.test
{
    opacity: 0.99;
    background: red;
    width: 100px;
    height: 100px;
}
.removeMe
{
    opacity: 0.01 !important;
}

JavaScript

$(function()
  {
      $(".test").removeClass("removeMe", 10000);
      $(".test").removeClass("removeMe");
  })