JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">Parent
    <div id="child">Child</div>
</div>

CSS

#parent {
    background: red;
}
#child {
    background: blue;
}
#parent:hover #child { /* this works */
    background: green;
}
#child:hover #parent { /* this does not work */
    background: yellow;
}