Drag to move, corner squares to resize. Drag on empty space to box-select; Shift-click adds to the selection. Pink guide lines snap edges and centres to other elements. Scroll or right-drag (or Space-drag) to pan, Ctrl+scroll or pinch to zoom, +/− zoom, F fit. Arrows nudge (Shift = 100 px). Hold Alt to skip snapping. Red notes and arrows explain behaviour.
Drawing: P pen, M marker, H highlighter, L straight line (hold Shift to lock to 15° steps, ends snap to the grid), C curve (drag to draw, then pull the round handles to bend it), E eraser (only erases drawings), V back to select. Pick an ink colour and thickness in the toolbar. Give a mark a label or note ("circle = make this bigger") and Claude gets it in the description.
Click to select, Shift-click to add. Drag to orbit, right-drag or Shift-drag to pan, wheel to zoom. G move, R rotate, S scale. Views: 1 front, 3 right, 7 top, 5 perspective, F fit. X deletes. Bevel presets round or chamfer edges; the sides slider turns cylinders into prisms and cones into pyramids. Drop down sets an object onto whatever is below it. Red pins are notes.
New blank clears the current mode. Ctrl+Z / Ctrl+Y undo and redo, Ctrl+C / Ctrl+X / Ctrl+V copy, cut and paste, Ctrl+A select all, Ctrl+D or Shift+D duplicate, Delete removes, Esc deselects. Lock stops big backgrounds (sections, floors, walls) from being grabbed by accident; locked items can still be picked from the Elements list. Pick what Claude should build it with in the Design panel. Your work is saved in this browser automatically; use Save to keep a file.