JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
    <div class="child"></div>
</div>

CSS

.child {
    background: #000;
    height: 300px;
    float: left;
    margin:15px 0 0 15px;
    width:150px;
    
}
.child:nth-child(3n+1) {
    clear: left;   
}