Techniques, not templates

Drag-to-Reorder That Opens a Gap

What sells a sortable list is not the row you are holding — it is what the other rows do. Swap them the instant you cross a boundary and the list flickers; instead, every row past the drop target shifts by exactly one row height, and the gap that opens up is the drop indicator. Two details carry it: transform rather than top or margin, so the shift stays composited at fifty rows, and a short transition, because anything over about 0.2s lags behind your finger and reads worse than no animation at all.