JSFiddle - React, Tailwind, and code Playground
HTML
<div class="sideNav">
Nav 1
</div>
<div class="sideNav">
Nav 2
</div>
<div class="sideNav">
Nav 3
</div>
CSS
.selected{
color:green;
}
JavaScript
$('.sideNav').click(function(){
$('.sideNav').removeClass("selected");
$(this).addClass("selected");
});