JSFiddle - React, Tailwind, and code Playground

HTML

<article class="sol1 clear">
    <h1>Soluzione 1</h1>
<div></div>
<div></div>
<div></div>
<br class="clear">
<div></div>
<div></div>
<br class="clear">
</article>

CSS

div{
    width:100px; height:100px;
    border:1px solid reD;

}

.sol1 div{
    float:left;
}

.clear{
    clear:both;
}