JSFiddle - React, Tailwind, and code Playground

HTML

<button type="button" id="make_larger">Large</button> 


<button type="button" id="make_small">Smaller</button> 

<button type="button" id="make_normal">Normal</button>

CSS

.selected {background: blue}

JavaScript

$('#make_larger').bind('click', function () {
        $('body').addClass('large');
        $('body').removeClass('normal');
        $('body').removeClass('smaller');
        $(this).addClass('selected');

     });