JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box expanded">Some text</div>

CSS

.box {
    border: 1px solid #5b5b5b;
    padding: 15px 40px;
    color: #fff;
    font-size: 13px;
    text-align: center;
    font-weight: bold;
    background: red;
    overflow:hidden;
}
.expanded {
    height: 279px;
    width: 200px;
    font-size: 20px;
    position: relative;
    z-index: 1000;
    background: red;
}
.expanded:after {
    content:'';
    position: absolute;
    height: 80px;
    width: 100%;
    top:100%;
    left:0;
    z-index: -999;
    background-color: #000;
    transition: all 1s;
    -webkit-transition: all 1s;
    -moz-transition: all 1s;
}
.expanded:hover:after {
    top:0;
}