JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
	<div class="box">1</div>
	<div class="box">2</div>
	<div class="divider"></div>
	<div class="box">3</div>
	<div class="box">4</div>
	<div class="box">5</div>
</div>

CSS

.box {
	min-width: 100px;
	height: 100px;
	margin: 2px;
	text-align: center;
	display: inline-block;
	border: 1px solid #000;
}
.divider { display: none; }
@media screen and (max-width: 600px) {
	.divider {
		clear: both;
        display: block;
	}
}