JSFiddle - React, Tailwind, and code Playground

HTML

<div class="right-large"></div> 
<div class="left"></div>
<div class="right-mobile"></div>

CSS

.left {
    overflow: hidden;
    min-height: 50px;
    border: 2px dashed #f0f
}

.right-large, .right-mobile {
    float: right;
    width: 250px;
    min-height: 50px;
    margin-left: 10px;
    border: 2px dashed #00f
}

.right-mobile{
    display: none;
}

@media only screen and (max-width: 600px) {
    .right-large{
        display: none;
    }
    .right-mobile {
        display: block;
        float: right;
        width: 100%;
    }
}