JSFiddle - React, Tailwind, and code Playground

HTML

<div class="PARENT">
<div class="RED">RED</div>
<div class="BLUE">BLUE</div>
<div class="GREEN">GREEN</div>   
</div>

CSS

.PARENT{
    position: relative;
    padding: 10px;
}

.RED{
    display: inline-block;
    margin: 5px;
    padding: 5px;
    color: #BB0000;
    background: #FFF;
    -webkit-box-sizing: border-box;
    -moz-box-sizing:    border-box;
    box-sizing:         border-box;
}

.RED:hover:after{
    display: block;
    width: calc(100% - 20px);
    height: calc(100% - 20px);
    background: transparent;
    border: 10px solid #BB0000;
    position: absolute;
    top: 0px;
    left: 0px;
    content: ' ';
    z-index: -1;
}

.BLUE{
    -webkit-box-sizing: border-box;
    -moz-box-sizing:    border-box;
    box-sizing:         border-box;
    display: inline-block;
    margin: 5px;
    padding: 5px;
    color: #0000BB;
    background: #FFF;
}
.BLUE:hover:after{
    display: block;
    width: calc(100% - 20px);
    height: calc(100% - 20px);
    background: transparent;
    border: 10px solid #0000BB;
    position: absolute;
    top: 0px;
    left: 0px;
    content: ' ';
    z-index: -1;
}
.GREEN{
    -webkit-box-sizing: border-box;
    -moz-box-sizing:    border-box;
    box-sizing:         border-box;
    display: inline-block;
    margin: 5px;
    padding: 5px;
    color: #00BB00;
    background: #FFF;
}
.GREEN:hover:after{
    display: block;
    width: calc(100% - 20px);
    height: calc(100% - 20px);
    background: transparent;
    border: 10px solid #00BB00;
    position: absolute;
    top: 0px;
    left: 0px;
    content: ' ';
    z-index: -1;
}