The fixed DRAG_RANGE_DP=200dp caused the collapse progress to advance faster than the visual height change, making the calendar feel like it "outruns" the finger. Now dragRangePx is computed as (weeks-1)×rowHeight, matching the actual visual height delta during collapse so finger movement maps 1:1 to visual change. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>