JSFiddle - React, Tailwind, and code Playground

HTML

<div class="first">1</div>
<div class="second">2</div>

CSS

div {
    height:44px;
    width:50px;
    border: 1px solid black;
    margin:24px;
    text-align:center;
    line-height:40px;
}

JavaScript

$('.first').hover(function(){
    $('.second').css('background','green')},
                  function(){
    $('.second').css('background','white')
})