Two 10 × 11 cm cards — modal editing (vi / Vim) for either side of a 15″ MacBook trackpad.
Print & cut
Print on A4, landscape. In the print dialog set Scale = 100% (not “Fit to page”) and turn Margins → None/Default — this keeps the cards at exactly 10 × 11 cm.
Cut along the dashed borders.
Slide card 1 under the keyboard on the left of the trackpad, card 2 on the right.
vi is modal. Most keys act in Normal mode — press i/a to Insert, Esc to return. Lines starting with : are the command line. Prefix a number to repeat (3dd = delete 3 lines). ⌃ = Ctrl. Vim-flavored (works in modern vi).
Preview below is shown enlarged; it prints at real size (10 × 11 cm each).