Too Long; Didn't ReadTL;DR:<em> </em><strong>Thinking in components — </strong>No longer do you have to maintain bunch of style-sheets. CSS-in-JS abstracts the CSS model to the component level, rather than the document level (modularity). design by Anna Dadej TL;DR: Thinking in components — No longer do you have to maintain bunch of style-sheets. CSS-in-JS abstracts the CSS model to the component