"‹ back" button in the top bar, per Benjamin's uplink ("dad gets click happy and jumps ahead but Ben wants to read the text at the bottom"). Steps back one card, jumps straight to the answer face (where the "why" text lives), and undoes that card's session-tally bump so re-marking it forward doesn't double-count. Greyed out on the first card of a session.
Bigger "why" text — was the smallest text on the card (.9rem, shrinking to .82rem on phones); bumped to 1.1rem / 1rem so it's readable without reading glasses.
Fixed dead "wrong-recycle" cooldown.WRONG_RECYCLE_MIN existed as a tunable since v1.0 but was never actually applied — wrong-marked cards were shuffled back in with brand-new unseen ones with no floor at all. Now they wait for that many other cards first, same mechanism right-cards already had. Should reduce the "didn't we just see this one" repeats reported via uplink.
v1.2.1 — tap-to-flip-back
Tap the answer face to flip back to the question. Previously the card only flipped one way (question → answer); an accidental tap left you stuck looking at the answer with no way back except marking it. Now tapping either face toggles the flip, and the back face has a matching "tap the card to flip back" hint.
v1.2 — mid-session filter change + topic filter
Topic filter now exposed in the UI (was in the data model since v1.0). New "topic" chip row on the setup screen: all / math / science / language / history / arts. Same chips also appear inside the new mid-session filter panel.
Filter panel — a ⚙ button in the top bar opens a slide-in panel with both difficulty and topic chips (plus a live "N cards match" preview). Changes take effect on the next card; the current visible card stays put so the mark you're about to make still records against the right question. Panel dismisses on the ✕, "done" button, or tapping the dark backdrop.
Smart summary on the filter button. The ⚙ icon is passive when both filters are on "all"; when you narrow the pool (e.g. math + easy), the button tints moon-gold and shows a compact ⚙ math · easy summary right in the top bar — you never have to open the panel to know what pool you're on.
Setup + panel chip states are mirrored — flip the filter one place, it flips in the other.
v1.1 — card flip
Card-flip reveal. v1.0 revealed the answer inline by hiding a "reveal answer" button and expanding a block below the question — functional but flat. v1.1 replaces it with a real 3D flip: the whole card rotates 180° on the Y-axis (GPU-composited rotateY, .65 s cubic-bezier easing), question on the front, answer + why on the back. Tap anywhere on the card face to flip. Pi-safe: single transform, no re-paints during the animation.
Mark bar fades in ~halfway through the flip so the buttons don't compete visually during the rotation.
Advancing to the next question snaps the card back to its front face without animation (the flip-out would flash the previous answer at the incoming question, which felt wrong).
Back face uses a slightly warmer parchment tint so the two sides feel distinct on quick glances.
v1.0 — first playable
600 cards across 5 categories (math / science / language / history / arts+logic), roughly balanced at 120 each.
Difficulty tagging (easy / medium / stretch), roughly 48 / 48 / 24 per category.
Setup screen: pick a difficulty filter (all / easy / medium / stretch), see progress stats (seen / missed / retired / total in pool).
Card flow: question → tap "reveal answer" → answer + "why" appear → mark ✓ / ✗ / 🗑 retire → next card.
Open-ended session: tap through until you tap leave. End-of-session tally shows totals.
Per-card state persisted to localStorage (night-deck:state) with three status values: wrong, right, retired.
Queue prioritises unseen + previously-missed cards. "Right" cards cool down for ~30 other-card marks before rejoining the rotation. "Retired" cards never come back unless progress is reset.
Auto-refill: if the queue drains mid-session, it rebuilds from the still-eligible pool so play doesn't stall.
"Reset progress" button on the setup screen wipes localStorage and starts fresh.
Aesthetic: deep navy background with a subtle starfield + moon accents; card face uses warm parchment-cream so questions read like a physical library card.
Landing page: new "learning" section separates study tools from games.
Seeded from the 60-question docs/brain-quest-plus.md deck Benjamin wrote; expanded ~10× per the design conversation.