JSFiddle - React, Tailwind, and code Playground
HTML
<div id="mydiv" tabindex="100"></div>
<div id="anotherdiv"></div>
CSS
#mydiv {
width: 50px;
height: 50px;
border: 1px solid red;
}
JavaScript
$("#mydiv").focusin(function() {
$("#mydiv").css("background", "red");
});
$("#mydiv").focusout(function() {
$("#mydiv").css("background", "white");
});