JSFiddle - React, Tailwind, and code Playground

HTML

<div class="bloc article">
       <span class="title">Actualités</span>
       <div class="contenu"></div>
    </div>

CSS

.bloc {
      background-color: red;
    }
    .bloc .article {
      background-color: green;
    }
    .bloc .title {
       background-color: blue;
    }