Hover.CSS CDN
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/hover.css/2.3.1/css/hover-min.css" />
Energetic Emu
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/hover.css/2.3.1/css/hover-min.css" />