JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
</div>

CSS

.box {
    width:100%;
    background:red;
    overflow:hidden;
}
.box div {
    width: 31.33333333333333%;
    float: left;
    background: blue;
    margin: 1%;
}