JSFiddle - React, Tailwind, and code Playground

HTML

<div class="cajas">
    <div>hola</div>
</div>
<div class="cajas">
    <div>estoy</div>
</div>
<div class="cajas">
    <div>aquĂ­</div>
</div>
<div class="cajas">
    <div>dentro</div>
</div>

CSS

div.cajas {
    float: left;
    width: 25%;
}

div.cajas div {
    margin: 0 5px;
    padding: 5px;
    height: 200px;
    border: 1px dashed red;
}

div.cajas:nth-child(even) div {
    border-color: green;
}