JSFiddle - React, Tailwind, and code Playground

HTML

<div test>Not the right way of applying styles</div>
<div class="rightApproach">The right way of applying styles</div>
<div id="idSelector">The right way of applying styles</div>

CSS

[test] {
    color:Orange;
}

.rightApproach {
    color:Brown;
}

#idSelector {
    color: Red;
}