iOS: Distinguish levels 2 and 3 in numbered lists (not just indent)

Levels 2 and 3 of a numbered list currently look identical to level 1. Only the indent differs, making hierarchy hard to read at a glance.

Request:

Differentiate nested levels visually — e.g. 1/2/3 → a/b/c → l/ll/lll/lV/V; the goal is that a reader can tell nesting depth without counting indents.