JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="floater">
    </div>
</div>

CSS

.floater {
    background-color: red;
    float: left;
    width: 50px;
    height: 100px;
}
.container {
    background-color: blue;
}
.container:before,
        .container:after {
            content:"";
            display:table;
        }

        .container:after {
            clear:both;
        }