Practise the systems

The eleven biological systems from souls, laid out as a living body you arrange by hand.

Stage 1 · Place. Tap the Systems card to fan the eleven open, then click or drag each into a placeholder. Click a placed one to send it back. When all are down, press Next stage — this locks the placements and removes Clear board.
Stage 2 · Reasons. Where a row's left+right (or the centroid) are placed, a smiley appears in the middle — click it to write a reason; it collapses on save. Click the centroid's smiley to draw confluence arrows from its row's left & right cards. Once you've written one, Next appears beside Back.
Stage 3 · Verbs. Each right-column system now shows its icon on its card. A + shows on each card's lower edge — click it to add a verb; saved verbs sit centred (a +N opens the full list). Once you've added one, Next reveals the subsystems.
Stage 4 · Subsystems. The Immune and Nervous systems glow; click one to fan its subsystems out as chips — to the right if the parent sits in the left column, to the left if it's on the right, above if it's the centroid. Click a subsystem and a system to thread a labelled line. Threaded ones leave the fan; click the line's label to add a reason/verb (or unthread). The reasons + emojis collapse under a Reasons toggle and verbs under a Verbs toggle. The progress bar tracks every stage.