Relates to #260 especially. If you were in a puzzle, then went up the trail to the meta, the icon should be an extra visual indication that the puzzle has been solved.
With the checkmark available in bootstrap, it can look something like this:
I could replace the icon with the check or turn the icon green instead.
Another option: use borders to circle the icon:
Relates to #260 especially. If you were in a puzzle, then went up the trail to the meta, the icon should be an extra visual indication that the puzzle has been solved.