JSFiddle - React, Tailwind, and code Playground

HTML

<article class="container">
  <div class="sm-screen">
    I'm first on small screens, second on large screens
  </div>
  <div class="lg-screen">
    I'm first on large screens, second on small screens
  </div>
</article>

CSS

div { height:300px }
.sm-screen{ background:coral }
.lg-screen{ background:cornflowerblue }

.container{ display:flex;flex-direction:column }
@media screen and (min-width:600px) {
  .container{ flex-direction:column-reverse }
}