Problem Solving & Design 75

Competent warm-dark campfire palette with thoughtful token system, but the concept and layout are exactly what you'd expect.

• +The intensity selector uses a radiogroup pattern with arrow-key navigation, making the three-option choice keyboard-accessible and semantically correct.
• +The result summary line composes people, hours, and intensity label into a single readable sentence, giving the user a confirmation of all three inputs at a glance.

Completeness 65

All core features are present and wired together — inputs, calculation, result display, backup tip, and reset — and the ResultCard includes an explicit empty-state handler that renders a static dash and prompt when result is null.

• +The result card shows a backup log recommendation as a distinct note element, fulfilling the brief's friendly-tip requirement.
• +The reset handler restores all four pieces of state — people, rawPeople, hours, intensity — and clears any validation error in one callback.
• -There are no loading or async states anywhere in the app; while the calculator is synchronous today, the absence of any pattern means adding async work later would require structural changes.

Technical Craft 70

The codebase is well-structured with typed interfaces, memoized calculations, and a dedicated calculator module, and a test file src/lib/calculator.test.ts is present, though its contents are not shown.

• +The log count is derived via useMemo, so it only recomputes when people, hours, or intensity actually change rather than on every render.
• +The FireVisual component applies an intensity-specific CSS class to its container, letting CSS control the visual difference between intensity levels, while always rendering exactly three spark divs regardless of intensity.