JSFiddle - React, Tailwind, and code Playground

HTML

<div class="copy">Hello World</div>

CSS

.copy {
    background: whitesmoke;
    display: block;
    line-height: 1;
    padding: 12px;
    color: #b0d66d;
    font-weight: 200;
    letter-spacing: .08em;
    opacity: 0;
/*-webkit-transition: opacity 1s ease;
    -moz-transition: opacity 1s ease;
    -o-transition: opacity 1s ease;
    transition: opacity 1s ease;*/
}
.copy:hover {
   /*opacity: 1;*/
}

JavaScript

$(".copy").hover(function(){
                    $(this).stop().animate({
                     opacity: '1'
                  }, 200, function() {
                    // Animation complete.
                  });
            
                }, function(){                            
                    $(this).stop().animate({
                     opacity: '0.1'
                  }, 200, function() {
                    // Animation complete.
                  });;            
                });