Problem Solving & Design B+

The domain logic is cleanly separated from the UI, validation covers all fields simultaneously, and the two-step delete confirmation prevents accidental data loss.

• +Validation collects errors for all three fields in a single pass and returns them together, so the user sees every problem at once rather than one at a time.
• +The delete button requires a second click within four seconds to confirm, with the armed state clearly labelled for screen readers.
• +The coverage function distinguishes four distinct states — none, invalid, enough, and short — each with its own typed return shape, making the UI branch exhaustive.

Completeness B

All four brief features are fully implemented with live updates, validation, and a clear coverage indicator, but there are no loading states and no error surfacing for unexpected runtime failures.

• +The coverage result renders immediately on every keystroke in the requirement field, giving users instant feedback without any submit action.
• +The empty state renders a custom SVG illustration and descriptive text when the stash has no entries.
• -There is no failure handling around risky operations such as DOM lookups — if any getElementById call returns null, the cast to HTMLElement will silently produce a broken reference that crashes at runtime with no user-visible message.
• -Loading states are entirely absent; the brief does not require async work, but the measured gap confirms this practice is missing from the build.

Technical Craft B+

The project uses TypeScript interfaces, a pure domain module with full Vitest coverage, CSS custom properties for a consistent visual system, and accessible focus and interaction states throughout.

• +All domain types are declared as explicit TypeScript interfaces and union types, keeping the shape of skeins, inputs, errors, and coverage results unambiguous.
• +The CSS defines all colours, shadows, and fonts as custom properties on :root, giving the entire UI a single source of truth for visual tokens.
• +A prefers-reduced-motion block disables all animations and transitions for users who have requested reduced motion.
• +The domain module's pure functions are exercised by a dedicated Vitest suite covering validation edge cases, subtotal arithmetic, coverage states, and immutability of add/remove.