JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <header>Header</header>
    <nav>Nav</nav>
    <article>Article</article>
</div>

CSS

.container{ 
    display: flex; flex-direction: row; 
    border: 2px solid SaddleBrown;
}
.container *{  
   background: ForestGreen; color: white; margin: 4px;
    flex-basis: 100px;
}
.container header{ order: 3; }
.container nav{ order: 1; }
.container article{ order: 2; }