The counters() CSS function enables combining markers when nesting counters. The function returns a string that concatenates the current values of the named and nested counters, if any are present, with the string provided. The third, optional parameter enables defining the list style....html <ol> <li> <ol> <li></li> <li></li> <li></li> </ol> </li>...<li></li> <li></li> <li> <ol> <li></li> <li> <ol> <li></li> <li></li>...