feat: proper mobile zoom

src/lib/Card.svelte

@@ -8,6 +8,7 @@
 		y?: number;
 		zIndex?: number;
 		canvasOffset?: { x: number; y: number };
+		canvasZoom?: number;
 		onMove?: (id: number, x: number, y: number) => void;
 		onClick?: (id: number) => void;
 		onDrop?: (id: number, x: number, y: number) => void;
@@ -22,6 +23,7 @@
 		y = $bindable(0),
 		zIndex = $bindable(0),
 		canvasOffset = { x: 0, y: 0 },
+		canvasZoom = 1,
 		onMove,
 		onClick,
 		onDrop
@@ -38,10 +40,11 @@
 		
 		isDragging = true;
 		hasMoved = false;
-		const rect = cardElement.getBoundingClientRect();
+		
+		// Calculate offset relative to card position in canvas coordinates
 		dragOffset = {
-			x: event.clientX - rect.left,
+			x: (event.clientX - canvasOffset.x) / canvasZoom - x,
-			y: event.clientY - rect.top
+			y: (event.clientY - canvasOffset.y) / canvasZoom - y
 		};
 		dragStartPos = {
 			x: event.clientX,
@@ -61,8 +64,8 @@
 			hasMoved = true;
 		}
 		
-		const newX = event.clientX - dragOffset.x - canvasOffset.x;
+		const newX = (event.clientX - canvasOffset.x) / canvasZoom - dragOffset.x;
-		const newY = event.clientY - dragOffset.y - canvasOffset.y;
+		const newY = (event.clientY - canvasOffset.y) / canvasZoom - dragOffset.y;
 		
 		x = newX;
 		y = newY;
@@ -84,6 +87,60 @@
 		}
 	}
 
+	function handleTouchStart(event: TouchEvent) {
+		if (event.touches.length !== 1) return;
+		event.stopPropagation(); // Prevent canvas panning
+		
+		const touch = event.touches[0];
+		isDragging = true;
+		hasMoved = false;
+		
+		// Calculate offset relative to card position in canvas coordinates
+		dragOffset = {
+			x: (touch.clientX - canvasOffset.x) / canvasZoom - x,
+			y: (touch.clientY - canvasOffset.y) / canvasZoom - y
+		};
+		dragStartPos = {
+			x: touch.clientX,
+			y: touch.clientY
+		};
+		
+		event.preventDefault();
+	}
+
+	function handleTouchMove(event: TouchEvent) {
+		if (!isDragging || event.touches.length !== 1) return;
+		
+		const touch = event.touches[0];
+		const deltaX = Math.abs(touch.clientX - dragStartPos.x);
+		const deltaY = Math.abs(touch.clientY - dragStartPos.y);
+		
+		if (deltaX > 10 || deltaY > 10) {
+			hasMoved = true;
+		}
+		
+		const newX = (touch.clientX - canvasOffset.x) / canvasZoom - dragOffset.x;
+		const newY = (touch.clientY - canvasOffset.y) / canvasZoom - dragOffset.y;
+		
+		x = newX;
+		y = newY;
+		
+		onMove?.(id, newX, newY);
+		event.preventDefault();
+	}
+
+	function handleTouchEnd(event: TouchEvent) {
+		if (isDragging) {
+			onDrop?.(id, x, y);
+			if (!hasMoved) {
+				flipped = !flipped;
+				onClick?.(id);
+			}
+		}
+		isDragging = false;
+		event.preventDefault();
+	}
+
 	$effect(() => {
 		if (isDragging) {
 			document.addEventListener('mousemove', handleMouseMove);
@@ -104,6 +161,9 @@
 	style="left: {x}px; top: {y}px; z-index: {zIndex};"
 	onmousedown={handleMouseDown}
 	onclick={handleClick}
+	ontouchstart={handleTouchStart}
+	ontouchmove={handleTouchMove}
+	ontouchend={handleTouchEnd}
 	role="button"
 	tabindex="0"
 >

src/lib/StickyNote.svelte

@@ -7,6 +7,7 @@
 		zIndex: number;
 		color: string;
 		canvasOffset?: { x: number; y: number };
+		canvasZoom?: number;
 		onMove?: (id: number, x: number, y: number) => void;
 		onUpdate?: (id: number, text: string) => void;
 		onDelete?: (id: number) => void;
@@ -20,6 +21,7 @@
 		zIndex = $bindable(0),
 		color,
 		canvasOffset = { x: 0, y: 0 },
+		canvasZoom = 1,
 		onMove,
 		onUpdate,
 		onDelete
@@ -38,10 +40,11 @@
 		
 		isDragging = true;
 		hasMoved = false;
-		const rect = noteElement.getBoundingClientRect();
+		
+		// Calculate offset relative to note position in canvas coordinates
 		dragOffset = {
-			x: event.clientX - rect.left,
+			x: (event.clientX - canvasOffset.x) / canvasZoom - x,
-			y: event.clientY - rect.top
+			y: (event.clientY - canvasOffset.y) / canvasZoom - y
 		};
 		dragStartPos = {
 			x: event.clientX,
@@ -61,8 +64,8 @@
 			hasMoved = true;
 		}
 		
-		const newX = event.clientX - dragOffset.x - canvasOffset.x;
+		const newX = (event.clientX - canvasOffset.x) / canvasZoom - dragOffset.x;
-		const newY = event.clientY - dragOffset.y - canvasOffset.y;
+		const newY = (event.clientY - canvasOffset.y) / canvasZoom - dragOffset.y;
 		
 		x = newX;
 		y = newY;
@@ -102,6 +105,59 @@
 		onDelete?.(id);
 	}
 
+	function handleTouchStart(event: TouchEvent) {
+		if (event.touches.length !== 1) return;
+		event.stopPropagation(); // Prevent canvas panning
+		
+		const touch = event.touches[0];
+		isDragging = true;
+		hasMoved = false;
+		
+		// Calculate offset relative to note position in canvas coordinates
+		dragOffset = {
+			x: (touch.clientX - canvasOffset.x) / canvasZoom - x,
+			y: (touch.clientY - canvasOffset.y) / canvasZoom - y
+		};
+		dragStartPos = {
+			x: touch.clientX,
+			y: touch.clientY
+		};
+		
+		event.preventDefault();
+	}
+
+	function handleTouchMove(event: TouchEvent) {
+		if (!isDragging || event.touches.length !== 1) return;
+		
+		const touch = event.touches[0];
+		const deltaX = Math.abs(touch.clientX - dragStartPos.x);
+		const deltaY = Math.abs(touch.clientY - dragStartPos.y);
+		
+		if (deltaX > 5 || deltaY > 5) {
+			hasMoved = true;
+		}
+		
+		const newX = (touch.clientX - canvasOffset.x) / canvasZoom - dragOffset.x;
+		const newY = (touch.clientY - canvasOffset.y) / canvasZoom - dragOffset.y;
+		
+		x = newX;
+		y = newY;
+		
+		onMove?.(id, newX, newY);
+		event.preventDefault();
+	}
+
+	function handleTouchEnd(event: TouchEvent) {
+		if (isDragging) {
+			if (!hasMoved) {
+				isEditing = true;
+				setTimeout(() => textareaElement?.focus(), 0);
+			}
+		}
+		isDragging = false;
+		event.preventDefault();
+	}
+
 	$effect(() => {
 		if (isDragging) {
 			document.addEventListener('mousemove', handleMouseMove);
@@ -122,6 +178,9 @@
 	style="left: {x}px; top: {y}px; z-index: {zIndex}; background-color: {color};"
 	onmousedown={handleMouseDown}
 	onclick={handleClick}
+	ontouchstart={handleTouchStart}
+	ontouchmove={handleTouchMove}
+	ontouchend={handleTouchEnd}
 	role="button"
 	tabindex="0"
 >

src/routes/+page.svelte

@@ -101,9 +101,13 @@
 
 	let deckPosition = $state({ x: 50, y: 300 });
 	let canvasOffset = $state({ x: 0, y: 0 });
+	let canvasZoom = $state(1);
 	let isDragging = $state(false);
 	let dragStart = $state({ x: 0, y: 0 });
 	let dragStartOffset = $state({ x: 0, y: 0 });
+	let isPinching = $state(false);
+	let lastPinchDistance = $state(0);
+	let pinchCenter = $state({ x: 0, y: 0 });
 
 	let cards = $state<CardData[]>([]);
 	let maxZIndex = $state(0);
@@ -304,12 +308,36 @@
 
 	function handleCanvasWheel(event: WheelEvent) {
 		event.preventDefault();
-		const scrollSpeed = 1;
-		canvasOffset.x -= event.deltaX * scrollSpeed;
-		canvasOffset.y -= event.deltaY * scrollSpeed;
 		
-		canvasOffset.x = Math.max(-2000, Math.min(2000, canvasOffset.x));
+		if (event.ctrlKey || event.metaKey) {
-		canvasOffset.y = Math.max(-2000, Math.min(2000, canvasOffset.y));
+			// Zoom with mouse wheel + ctrl/cmd towards viewport center
+			const zoomFactor = event.deltaY > 0 ? 0.9 : 1.1;
+			const newZoom = Math.max(0.1, Math.min(3, canvasZoom * zoomFactor));
+			
+			// Get viewport center
+			const rect = (event.currentTarget as HTMLElement).getBoundingClientRect();
+			const centerX = rect.width / 2;
+			const centerY = rect.height / 2;
+			
+			// Convert viewport center to canvas coordinates before zoom
+			const canvasCenterX = (centerX - canvasOffset.x) / canvasZoom;
+			const canvasCenterY = (centerY - canvasOffset.y) / canvasZoom;
+			
+			// Update zoom
+			canvasZoom = newZoom;
+			
+			// Adjust offset to keep the viewport center fixed
+			canvasOffset.x = centerX - canvasCenterX * canvasZoom;
+			canvasOffset.y = centerY - canvasCenterY * canvasZoom;
+		} else {
+			// Pan with mouse wheel
+			const scrollSpeed = 1 / canvasZoom; // Adjust pan speed for zoom level
+			canvasOffset.x -= event.deltaX * scrollSpeed;
+			canvasOffset.y -= event.deltaY * scrollSpeed;
+			
+			canvasOffset.x = Math.max(-2000, Math.min(2000, canvasOffset.x));
+			canvasOffset.y = Math.max(-2000, Math.min(2000, canvasOffset.y));
+		}
 	}
 
 	function handleCanvasMouseDown(event: MouseEvent) {
@@ -344,6 +372,96 @@
 		event.preventDefault();
 	}
 
+	function getTouchDistance(touches: TouchList) {
+		if (touches.length < 2) return 0;
+		const touch1 = touches[0];
+		const touch2 = touches[1];
+		return Math.sqrt(
+			Math.pow(touch2.clientX - touch1.clientX, 2) + 
+			Math.pow(touch2.clientY - touch1.clientY, 2)
+		);
+	}
+
+	function getTouchCenter(touches: TouchList) {
+		if (touches.length < 2) return { x: 0, y: 0 };
+		const touch1 = touches[0];
+		const touch2 = touches[1];
+		return {
+			x: (touch1.clientX + touch2.clientX) / 2,
+			y: (touch1.clientY + touch2.clientY) / 2
+		};
+	}
+
+	function handleCanvasTouchStart(event: TouchEvent) {
+		isDragging = true;
+		if (event.touches.length >= 2) {
+			// Two or more touches - pinch zoom
+			isPinching = true;
+			lastPinchDistance = getTouchDistance(event.touches);
+			pinchCenter = getTouchCenter(event.touches);
+			
+			// Convert pinch center to canvas coordinates
+			const rect = (event.currentTarget as HTMLElement).getBoundingClientRect();
+			pinchCenter.x -= rect.left;
+			pinchCenter.y -= rect.top;
+		} else if (event.touches.length === 1) {
+			// Single touch - pan
+			const touch = event.touches[0];
+			dragStart.x = touch.clientX;
+			dragStart.y = touch.clientY;
+			dragStartOffset.x = canvasOffset.x;
+			dragStartOffset.y = canvasOffset.y;
+		}
+		event.preventDefault();
+	}
+
+	function handleCanvasTouchMove(event: TouchEvent) {
+		if (event.touches.length === 1 && isDragging && !isPinching) {
+			// Single touch pan
+			const touch = event.touches[0];
+			const deltaX = touch.clientX - dragStart.x;
+			const deltaY = touch.clientY - dragStart.y;
+			
+			canvasOffset.x = Math.max(-2000, Math.min(2000, dragStartOffset.x + deltaX));
+			canvasOffset.y = Math.max(-2000, Math.min(2000, dragStartOffset.y + deltaY));
+		} else if (event.touches.length === 2 && isPinching) {
+			// Pinch zoom
+			const currentDistance = getTouchDistance(event.touches);
+			const zoomFactor = currentDistance / lastPinchDistance;
+			const newZoom = Math.max(0.1, Math.min(3, canvasZoom * zoomFactor));
+			
+			// Convert pinch center to canvas coordinates before zoom
+			const canvasCenterX = (pinchCenter.x - canvasOffset.x) / canvasZoom;
+			const canvasCenterY = (pinchCenter.y - canvasOffset.y) / canvasZoom;
+			
+			// Update zoom
+			canvasZoom = newZoom;
+			
+			// Adjust offset to keep the pinch center fixed
+			canvasOffset.x = pinchCenter.x - canvasCenterX * canvasZoom;
+			canvasOffset.y = pinchCenter.y - canvasCenterY * canvasZoom;
+			
+			lastPinchDistance = currentDistance;
+		}
+		event.preventDefault();
+	}
+
+	function handleCanvasTouchEnd(event: TouchEvent) {
+		if (event.touches.length === 0) {
+			isDragging = false;
+			isPinching = false;
+		} else if (event.touches.length === 1) {
+			isPinching = false;
+			// A pinch ended. Reset pan state for the remaining finger to prevent a jump.
+			const touch = event.touches[0];
+			dragStart.x = touch.clientX;
+			dragStart.y = touch.clientY;
+			dragStartOffset.x = canvasOffset.x;
+			dragStartOffset.y = canvasOffset.y;
+		}
+		event.preventDefault();
+	}
+
 	function addStickyNote() {
 		const randomColor = noteColors[Math.floor(Math.random() * noteColors.length)];
 		const newNote: StickyNote = {
@@ -387,6 +505,7 @@
 			cards: cards.map(card => ({...card})),
 			stickyNotes: stickyNotes.map(note => ({...note})),
 			canvasOffset,
+			canvasZoom,
 			deckPosition,
 			maxZIndex,
 			nextNoteId,
@@ -431,6 +550,7 @@
 					cards = canvasState.cards || [];
 					stickyNotes = canvasState.stickyNotes || [];
 					canvasOffset = canvasState.canvasOffset || { x: 0, y: 0 };
+					canvasZoom = canvasState.canvasZoom || 1;
 					deckPosition = canvasState.deckPosition || { x: 50, y: 300 };
 					maxZIndex = canvasState.maxZIndex || cards.length;
 					nextNoteId = canvasState.nextNoteId || 1;
@@ -485,16 +605,20 @@
 		onmousemove={handleCanvasMouseMove}
 		onmouseup={handleCanvasMouseUp}
 		oncontextmenu={handleCanvasContextMenu}
+		ontouchstart={handleCanvasTouchStart}
+		ontouchmove={handleCanvasTouchMove}
+		ontouchend={handleCanvasTouchEnd}
 	>
 		<div 
 			class="canvas-content" 
-			style="transform: translate({canvasOffset.x}px, {canvasOffset.y}px);"
+			style="transform: translate({canvasOffset.x}px, {canvasOffset.y}px) scale({canvasZoom});"
 		>
 			{#each cards as card (card.id)}
 				<Card
 					{...card}
 					backImage={card.isRiskCategory ? 'risks/risikocat_back.png' : backImage}
 					canvasOffset={canvasOffset}
+					canvasZoom={canvasZoom}
 					bind:flipped={card.flipped}
 					bind:x={card.x}
 					bind:y={card.y}
@@ -509,6 +633,7 @@
 				<StickyNote
 					{...note}
 					canvasOffset={canvasOffset}
+					canvasZoom={canvasZoom}
 					bind:text={note.text}
 					bind:x={note.x}
 					bind:y={note.y}
@@ -597,18 +722,40 @@
 		height: 100%;
 		overflow: hidden;
 		cursor: grab;
+		touch-action: none;
+		user-select: none;
 	}
 
 	.game-area:active {
 		cursor: grabbing;
 	}
 
+	@media (max-width: 768px) {
+		.controls {
+			top: 10px;
+			right: 10px;
+			gap: 5px;
+			flex-direction: column;
+			align-items: flex-end;
+		}
+		
+		.control-group {
+			padding: 6px 10px;
+		}
+		
+		.controls button {
+			padding: 8px 12px;
+			font-size: 14px;
+		}
+	}
+
 	.canvas-content {
 		position: relative;
 		width: 500vw;
 		height: 500vh;
 		min-width: 500vw;
 		min-height: 500vh;
+		transform-origin: 0 0;
 	}
 
 	.deck-area {