JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="c1"></div>
    <div class="c2"></div>
</div>

CSS

div {
    width: 100px; height: 100px;
}

.parent div {
    position: absolute;
}
.parent .c1 {
    background-color: #800000
}
.parent .c2 {
    background-color: #000080
}

.parent:hover .c1 {
    z-index: 1;
}