On my maps marked trails don't have tags "highway", thats why they won't be visible with conditions that you have included into your style.
I add artificial tag route=hiking|foot|bicycle|mtb|ski|sled|piste|ferry (maybe more, values are taken from relation type).
Edit: I add new ways for marked trails to OSM data, there should be an original way with tag highway= at the same place.
I add artificial tag route=hiking|foot|bicycle|mtb|ski|sled|piste|ferry (maybe more, values are taken from relation type).
Edit: I add new ways for marked trails to OSM data, there should be an original way with tag highway= at the same place.