JSFiddle - React, Tailwind, and code Playground

HTML

<div class='foo'>Hi there</div><div class='foo'>Hi there</div><div class='foo'>Hi there</div><div class='foo'>Hi there</div><div class='foo'>Hi there</div>

CSS

.foo{
    color:#fff;
    font-size:22px;
    padding:5px 10px;
    text-align:center;
    background:#3498db;
}
.foo:nth-child(2n+1){
    background:#2980b9;
    color:#fff;
}

JavaScript

$(function(){
    $('.foo').hide();
});