JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <div></div>
</div>

<div id="original">
</div>

<div id="quarter">
</div>

CSS

#parent div, #original, #quarter {
    width: 100px;
    height: 100px;
    background-color: orange;
}

#parent div {
    opacity: 0.5;
}

#parent {
    opacity: 0.5;
}

#quarter {
    opacity: 0.25;
}