JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test-wrapper">
    <div class="test-div">Div 1</div>
    <div class="test-div">Div 2</div>
    <div class="test-div">Div 3</div>
</div>

CSS

.test-wrapper {
    width:960px;
}
.test-div {
    float:left;
    width:200px;
    height:200px;
    border: 1px solid black;
    margin:20px;
}

@media only screen and (max-width: 960px) {
    .test-div {
        float:none;
    }
}