JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    Já vai embora?
</div>

CSS

div{
    display: none;
    background: yellow;
}

JavaScript

// quando o mouse sai do viewport
$(document).on("mouseleave", function(){
    $("div").show();
});

// quando o mouse entra do viewport
$(document).on("mouseenter", function(){
    $("div").hide();
});