- Resize by dragging selection handles (8 positions: corners + edges)
- Shift+resize maintains aspect ratio
- Marquee selection: drag on empty canvas to select nodes in rectangle
- Alt+drag to duplicate and move selected nodes
- Cmd+D to duplicate in place (+20px offset)
- Cmd+A to select all
- Shift+draw constrains to square/circle
- Cursor changes to resize arrows on handle hover
- Marquee drawn as blue transparent rect with selection stroke