JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="a"></div>
    <div></div>
    <div class="b"></div>
    <div></div>
</div>

CSS

.container { font-size: 0; }
.container div { display:inline-block; width: 100px; height: 30px; background: #000000; font-size: 12px; }
.container div.a { width: 130px; background: #555555; }
.container div.b { width: 70px; background: #333333; }

@media (max-width: 720px) {
    .container div{
        display:block;
                /* Andere eigenschappen */
    }
}