feels pretty polished, though it could use a way to make the mouse's movement a bit more incremental as the visualization can jump drastically when moving even a pixel when zoomed out to see the entirety of the course.
I also struggled with the really fine mouse movements but I was hamstrung by a bad laptop trackpad the whole time 'XD. I was gonna suggest maybe you could make it so you can select an element then tap the arrow keys to do fine adjustments?
