JSFiddle - React, Tailwind, and code Playground

HTML

<h1 id="first">First header</h1>
<h1 id="second">Second header</h1>

JavaScript

$("#first").mouseover(function(){
	$("#second").css({
    'background-color' : '#ccc'
  });
}).mouseout(function() {
  $("#second").css({
    'background-color' : 'transparent'
  });
});

$("#second").mouseover(function(){
	$("#first").css({
    'background-color' : '#ddd'
  });
}).mouseout(function() {
  $("#first").css({
    'background-color' : 'transparent'
  });
});