JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block"></div>

CSS

.block {
    width: 100px;
    height: 100px;
    
    position: relative;
    
    background: linear-gradient(black, red);
}

.block:before {
    content: "";
    
    position: absolute;    
    top: 0;     left: 0;
    bottom: 0;  right: 0;
    
    background: linear-gradient(red, black);
    
    -webkit-transition: opacity 0.3s ease;
    transition: opacity 0.3s ease;
}

.block:hover:before {
    opacity: 0;
}