Hi, thank you for the thoughtful review! I definitely understand deleting something by mistake is frustrating. When deleting something, you should see a blue notification bubble appear at the top for a short time; clicking it will undo the deletion (or if you've done multiple deletions recently, it will take you to the deleted-items page).

I went with this approach instead of the confirmation like you suggested, because interrupting the user to ask for confirmation on every delete can be pretty obtrusive—95% of the time, the answer is "yes, I meant to do that". "Undo" gives you an easy way to fix any mistakes while still (mostly) staying out of your way.

I'll keep your other UI feedback (e.g. about the separator line and stacking up too many items) in mind for future releases. Thanks again!