Counting Itself

counting itself — flat, then by nesting depth

ol { counter-reset: section; }
li { counter-increment: section; }

/* counter() — just my own number */
li::marker     { content: counter(section) " "; }

/* counters() — one level per ancestor: 1, 1.1, 1.1.1 */
li li::marker  { content: counters(section, ".") " "; }