JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div {
    width:100px;
    height:100px;
    border: 1px solid #ccc;
}

JavaScript

animateCorners = function(event) {

    r = (event.type == 'mouseenter' ? 40 : 0);
    $(this).css({
        'border-top-left-radius': r,
        'border-top-right-radius': r,
        'border-bottom-right-radius': r,
        'border-bottom-left-radius': r
    });

}
$('div').hover(animateCorners, animateCorners);