chore(release): 4.63.0 [skip ci]

## [4.63.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.62.1...v4.63.0) (2025-10-21)

### Features

* **flashcards:** add grab point physics for realistic rotation ([bf37eb1](bf37eb1928))

CHANGELOG.md

@@ -1,3 +1,24 @@
+## [4.63.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.62.1...v4.63.0) (2025-10-21)
+
+
+### Features
+
+* **flashcards:** add grab point physics for realistic rotation ([bf37eb1](https://github.com/antialias/soroban-abacus-flashcards/commit/bf37eb1928de8d07673234e2faa1fa6268c45686))
+
+## [4.62.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.62.0...v4.62.1) (2025-10-21)
+
+
+### Bug Fixes
+
+* **flashcards:** improve shadow speed logging with separate throttling ([0f51366](https://github.com/antialias/soroban-abacus-flashcards/commit/0f51366fd56540e691df4931b6350c03043484f1))
+
+## [4.62.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.61.3...v4.62.0) (2025-10-21)
+
+
+### Features
+
+* **flashcards:** add dynamic shadow based on drag speed ([92148a4](https://github.com/antialias/soroban-abacus-flashcards/commit/92148a4cf87e828ba2e5ec1740fb51d9667c1d73))
+
 ## [4.61.3](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.61.2...v4.61.3) (2025-10-21)
 
 

apps/web/src/components/InteractiveFlashcards.tsx

@@ -94,16 +94,24 @@ interface DraggableCardProps {
 function DraggableCard({ card }: DraggableCardProps) {
   // Track position - starts at initial, updates when dragged
   const [position, setPosition] = useState({ x: card.initialX, y: card.initialY })
-  const [rotation] = useState(card.initialRotation)
+  const [rotation, setRotation] = useState(card.initialRotation) // Now dynamic!
   const [zIndex, setZIndex] = useState(card.zIndex)
   const [isDragging, setIsDragging] = useState(false)
+  const [dragSpeed, setDragSpeed] = useState(0) // Speed for dynamic shadow
 
   // Track drag state
   const dragStartRef = useRef<{ x: number; y: number; cardX: number; cardY: number } | null>(null)
+  const grabOffsetRef = useRef<{ x: number; y: number }>({ x: 0, y: 0 }) // Offset from card center where grabbed
+  const baseRotationRef = useRef(card.initialRotation) // Starting rotation
+  const lastMoveTimeRef = useRef<number>(0)
+  const lastMovePositionRef = useRef<{ x: number; y: number }>({ x: 0, y: 0 })
+  const lastLogTimeRef = useRef<number>(0) // Separate throttling for logging
+  const cardRef = useRef<HTMLDivElement>(null) // Reference to card element
 
   const handlePointerDown = (e: React.PointerEvent) => {
     setIsDragging(true)
     setZIndex(1000) // Bring to front
+    setDragSpeed(0)
 
     // Capture the pointer
     e.currentTarget.setPointerCapture(e.pointerId)
@@ -115,6 +123,31 @@ function DraggableCard({ card }: DraggableCardProps) {
       cardX: position.x,
       cardY: position.y,
     }
+
+    // Calculate grab offset from card center
+    if (cardRef.current) {
+      const rect = cardRef.current.getBoundingClientRect()
+      const cardCenterX = rect.left + rect.width / 2
+      const cardCenterY = rect.top + rect.height / 2
+      grabOffsetRef.current = {
+        x: e.clientX - cardCenterX,
+        y: e.clientY - cardCenterY,
+      }
+      console.log(
+        `[GrabPoint] Grabbed at offset: (${grabOffsetRef.current.x.toFixed(0)}, ${grabOffsetRef.current.y.toFixed(0)})px from center`
+      )
+    }
+
+    // Store the current rotation as the base for this drag
+    baseRotationRef.current = rotation
+
+    // Initialize velocity tracking
+    const now = Date.now()
+    lastMoveTimeRef.current = now
+    lastMovePositionRef.current = { x: e.clientX, y: e.clientY }
+    lastLogTimeRef.current = now
+
+    console.log('[Shadow] Drag started, speed reset to 0')
   }
 
   const handlePointerMove = (e: React.PointerEvent) => {
@@ -124,6 +157,47 @@ function DraggableCard({ card }: DraggableCardProps) {
     const deltaX = e.clientX - dragStartRef.current.x
     const deltaY = e.clientY - dragStartRef.current.y
 
+    // Calculate velocity for dynamic shadow
+    const now = Date.now()
+    const timeDelta = now - lastMoveTimeRef.current
+
+    if (timeDelta > 0) {
+      // Distance moved since last frame
+      const distX = e.clientX - lastMovePositionRef.current.x
+      const distY = e.clientY - lastMovePositionRef.current.y
+      const distance = Math.sqrt(distX * distX + distY * distY)
+
+      // Speed in pixels per millisecond, then convert to reasonable scale
+      const speed = distance / timeDelta
+      const scaledSpeed = Math.min(speed * 100, 100) // Cap at 100 for reasonable shadow size
+
+      setDragSpeed(scaledSpeed)
+
+      // Log occasionally (every ~200ms) to avoid console spam
+      const timeSinceLastLog = now - lastLogTimeRef.current
+      if (timeSinceLastLog > 200) {
+        console.log(
+          `[Shadow] Speed: ${scaledSpeed.toFixed(1)}, distance: ${distance.toFixed(0)}px, timeDelta: ${timeDelta}ms`
+        )
+        lastLogTimeRef.current = now
+      }
+
+      lastMoveTimeRef.current = now
+      lastMovePositionRef.current = { x: e.clientX, y: e.clientY }
+    }
+
+    // Calculate rotation based on grab point physics
+    // Cross product of grab offset and drag direction determines rotation
+    // If grabbed on left and dragged right → clockwise rotation
+    // If grabbed on right and dragged left → counter-clockwise rotation
+    const crossProduct = grabOffsetRef.current.x * deltaY - grabOffsetRef.current.y * deltaX
+    const rotationInfluence = crossProduct / 5000 // Scale factor for reasonable rotation (adjust as needed)
+    const newRotation = baseRotationRef.current + rotationInfluence
+
+    // Clamp rotation to prevent excessive spinning
+    const clampedRotation = Math.max(-45, Math.min(45, newRotation))
+    setRotation(clampedRotation)
+
     // Update card position
     setPosition({
       x: dragStartRef.current.cardX + deltaX,
@@ -135,12 +209,38 @@ function DraggableCard({ card }: DraggableCardProps) {
     setIsDragging(false)
     dragStartRef.current = null
 
+    console.log('[Shadow] Drag released, speed decaying to 0')
+    console.log(
+      `[GrabPoint] Final rotation: ${rotation.toFixed(1)}° (base was ${baseRotationRef.current.toFixed(1)}°)`
+    )
+
+    // Gradually decay speed back to 0 for smooth shadow transition
+    const decayInterval = setInterval(() => {
+      setDragSpeed((prev) => {
+        const newSpeed = prev * 0.8 // Decay by 20% each frame
+        if (newSpeed < 1) {
+          clearInterval(decayInterval)
+          return 0
+        }
+        return newSpeed
+      })
+    }, 50) // Update every 50ms
+
     // Release the pointer capture
     e.currentTarget.releasePointerCapture(e.pointerId)
   }
 
+  // Calculate dynamic shadow based on drag speed
+  // Base shadow: 0 8px 24px rgba(0, 0, 0, 0.3)
+  // Fast drag: 0 32px 64px rgba(0, 0, 0, 0.6)
+  const shadowY = 8 + (dragSpeed / 100) * 24 // 8px to 32px
+  const shadowBlur = 24 + (dragSpeed / 100) * 40 // 24px to 64px
+  const shadowOpacity = 0.3 + (dragSpeed / 100) * 0.3 // 0.3 to 0.6
+  const boxShadow = `0 ${shadowY}px ${shadowBlur}px rgba(0, 0, 0, ${shadowOpacity})`
+
   return (
     <div
+      ref={cardRef}
       onPointerDown={handlePointerDown}
       onPointerMove={handlePointerMove}
       onPointerUp={handlePointerUp}
@@ -159,20 +259,20 @@ function DraggableCard({ card }: DraggableCardProps) {
       })}
     >
       <div
+        style={{
+          boxShadow, // Dynamic shadow based on drag speed
+        }}
         className={css({
           bg: 'white',
           rounded: 'lg',
           p: '4',
-          boxShadow: isDragging
-            ? '0 16px 48px rgba(0, 0, 0, 0.5)'
-            : '0 8px 24px rgba(0, 0, 0, 0.3)',
           display: 'flex',
           flexDirection: 'column',
           alignItems: 'center',
           gap: '2',
           minW: '120px',
           border: '2px solid rgba(0, 0, 0, 0.1)',
-          transition: 'box-shadow 0.2s',
+          transition: 'box-shadow 0.1s', // Quick transition for responsive feel
         })}
       >
         {/* Abacus visualization */}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "soroban-monorepo",
-  "version": "4.61.3",
+  "version": "4.63.0",
   "private": true,
   "description": "Beautiful Soroban Flashcard Generator - Monorepo",
   "workspaces": [