How to use
• Drag canvas to pan • Scroll wheel to zoom
• Draw Room → drag on canvas to add a rectangular room
• Draw Wall → drag to add a free-standing wall (snaps to horizontal/vertical; hold Shift for any angle)
• Click anything to select; drag to move; corner/endpoint handles to resize
• Dashed yellow box is the 26' × 16' extension area — drag it to reposition
• Saves automatically to this browser. Export PNG / JSON to share.