Drag the Words target area should be visibly darker when it's active

There has now been several request to get the target area of Drag the Words to be more darker when it's active (= when the draggable word is hovering top of it).

Many people seem to fail to get the word on to the right spot, especially when word mostly covers the text area, so color change of the field is not that obvious even with better vision.

Other thing that could help if the actual target area was actually bigger than visible field so user did not need to be as presise with it.