JSFiddle - React, Tailwind, and code Playground

HTML

<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>

CSS

.item {
  width: 250px;
  height: 15px;
}

.item {
  background: #ccc;
}

.item:nth-child(even) {
  background: #000;
}