Changelog

End-to-end verification before shipping: type, lint, test, build, and runtime checks across the whole atlas. Caught and fixed four real bugs ranging from a stylistic regression to a hydration mismatch.

• Fixed broken tinted backgrounds across QuizEngine, CaseRunner, PracticeClient, and WaveformSimulator. The old `${tokens.color.X}NN` hex+alpha pattern silently became invalid CSS once tokens switched to CSS variables; answer-reveal highlights were rendering transparent. Replaced with a new tint() helper using color-mix().
• Fixed the timed quiz personal best not updating when the round auto-finished on time-out. Extracted maybeUpdateBest() and called it from both manual finish and the auto-finish effect.
• Fixed a memory leak in the waveform simulator drag handlers. Each render's new handler identity was being added as a listener and the wrong identity removed, stacking listeners across drags. Rewrote with stable refs.
• Fixed a hydration mismatch on the pattern recognition trainer caused by Math.random() in useState initial value. Now seeds with a fixed value for SSR and randomises after first paint.
• Added a regression test that scans the source tree for the old broken-tint pattern so it can never re-enter the codebase.

Three orientations for studying: audio walkthrough scripts on the major modules, a Your Progress dashboard pulling every locally-stored signal into one view, and the very page you're reading.

• Audio walkthrough player on Anatomy, Technique, Normal waves, SCD, and Neuritis — collapsed by default, expands to the timestamped narration script. Falls back to text gracefully when no audio file is recorded yet.
• Progress dashboard at /progress: chapters visited, time on atlas, quiz progress by level, Leitner and Streak deck stats, timed-mode best score, bookmarked terms, per-chapter time.
• Per-module 'Save as PDF / print' button now uses A4 page geometry and tightened pagination — figures, tables and headings hold together across page breaks.
• Changelog page (this one) with sidebar badge that announces unseen entries.

The quiz gained three top-level modes and several power tools: Browse with both level + topic filters, Spaced review with Leitner-box and 3-in-a-row sub-strategies, and Timed (ten random questions in five minutes).

• 11-topic taxonomy across every question — anatomy, technique, interpretation, and disease-specific tags compose with the existing difficulty filter.
• Streak-based SRS as an alternative to the Leitner scheduler. Three correct in a row graduates a card; a miss resets to zero. Both decks coexist; the user picks per session.
• Deep-linked 'Read more →' links from every explanation, landing on the relevant chapter section via anchor id.
• Timed mode persists a personal best (correct + fastest time) in localStorage.

Random-archetype practice generator at /practice, an overlay mode on /compare so two diseases share one set of axes, and a representative audiogram on every disease page to tie the testing battery together.

• Nine archetypes covering the major disease patterns; each instantiation produces a slightly different trace (mild jitter) so cases are effectively infinite.
• Seven-finding vocabulary (reduced amplitude, augmented amplitude, absent response, prolonged latency, asymmetric, lowered threshold, frequency-tuning shift) graded against the archetype's truth set.
• Compare page now offers Overlay (one set of axes, both traces) and Panels-vs-normal (two side-by-side comparisons).
• Every disease page now pairs its VEMP signature with a representative audiogram and a teaching caption.

A first round of post-launch upgrades focused on interactivity and bedside-style learning.

• 8 hand-authored clinical cases at /cases with vignette → tests → diagnosis → teaching point.
• Leitner-box spaced repetition tab in the quiz, persisted to localStorage.
• P1 and N1 are now draggable handles on the waveform simulator.
• Side-by-side comparison page comparing any disease against a normal reference.
• Light / Dark / Auto theme toggle in the sidebar, respecting prefers-color-scheme.
• Reflex arc diagram pulses now travel along each path, illustrating signal flow.

The atlas was rebuilt from the static HTML prototype into a TypeScript-strict Next.js 14 static export, matching the prior VNG Atlas stack.

• Hand-rolled SVG waveform simulator with adjustable P1, N1, and amplitude sliders for both ears.
• Layered content (Foundation / Trainee / Clinician), per-page level filter.
• Search across chapters and glossary, keyboard-accessible.
• 24-question self-assessment with explanations.