JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="child">

    </div>
</div>

CSS

.parent {
    transition:background-color 1s;
    width:100px;
    height:100px;
    background:#3D6AA2;
    padding:50px;
}

.parent:hover {
    background:#FFF;
}

.child {
    height:100px;
    width:100px;
    background:#355E95;
    transition:background-color 1s;
}

.child:hover {
    
    background:#000;
}