Use negative nth-child and nth-last-child

`nth-child` is used to choose a child or a range of children of a given element. Using negative `nth-child` will pick the first few children.

In the following example, the first three items will be underlined. The range of second to fifth items have the blue color.

li:nth-child(-n + 3) {
    text-decoration: underline;
}
li:nth-child(n + 2):nth-child(-n + 5) {
    color: #2563eb;
}

In a similar way, nagative `nth-last-child` will pick the last few children.

/* Add a decorative line to the last two items */
li:nth-last-child(-n + 2) {
    text-decoration-line: line-through;
}

Use negative nth-child and nth-last-child