Big goals are rarely a single thing. "Get fit this year" is really "run a 5k by April, hit the gym twice a week, learn to cook dinner at home." So goals can now contain other goals.

Break any goal into sub-goals. Drag a sub-goal sideways under another to nest it. Drag it back out to un-nest. Progress rolls up automatically. Finish all the sub-goals and the parent marks itself done.

One level deep for now. Most things fit in two layers.