A nested list of DIV-s, the ones containing grand-children having a border.
div! > div > div {
border: 4px solid red;
}When hovering a
grand-child, the grand-parent div shows a message in
yellow.div:after! > div > div:hover{
display:block;
content: "Too many nested DIVs.";
background-color:yellow;
padding:1em;
}