JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Документ без названия</title>
</head>
<body>
<a href="" id="a">123</a>
<strong>789</strong>
<p id="p">456</p>
</body>
</html>

CSS

#a {
    color:#0F0;
}
#a:hover {
    color: #000;
}
#p {
    color: #C00;
    display:none;
}
#a:hover ~ p {
    color: #C0F;
    display:block;
}