Problem Solving & Design B

The domain logic is cleanly separated from the DOM layer, burn rates match the brief exactly, and the two-step delete confirmation prevents accidental data loss.

• +Burn rates for all four wax types match the brief's specified values exactly, defined in one place and reused everywhere.
• +The two-step delete flow arms a button on first click and requires a second click to confirm, preventing accidental removal of saved candles.
• +Stored data is validated through normalizeSaved on load, so corrupt or tampered localStorage entries are rejected and the user is informed rather than silently broken.

Completeness B+

All brief features are fully implemented, but validation errors are shown inline in the form while storage failures surface via a banner — user-facing error feedback for failed saves is limited to the save-error paragraph rather than a prominent recoverable state.

• +The ±10% range is computed and formatted exactly as the brief specifies, including singular/plural handling and collapsed bounds when low equals high.
• +The saved-candle list enforces the 5-entry cap and disables the save button with an explanatory message when the cap is reached.
• +An empty-state message is shown in the saved section before any candles are added, and a separate empty prompt is shown in the result panel before inputs are filled.
• -When localStorage.setItem throws (e.g. quota exceeded), the failure is reported only to a banner that may already be hidden or ignored — there is no inline error near the save button to tell the user their candle was not actually persisted.

Technical Craft B

The codebase is well-structured with named pure functions, responsive layout tokens, accessible markup, and a full automated test suite, though JSDoc type annotations substitute for formal TypeScript type definitions.

• +Design tokens for colour, spacing and radius are declared once in :root and referenced via var() throughout the stylesheet.
• +A visible :focus-visible outline is defined globally, ensuring keyboard users can track focus across all interactive elements.
• +The flame animation respects prefers-reduced-motion by disabling it entirely for users who have requested reduced motion.
• +The automated test suite covers unit conversion, validation edge cases, formatting, and normalization of saved data.
• -The project uses JSDoc @typedef comments for type information rather than TypeScript interfaces or type aliases, so types are not statically enforced by the compiler and can drift from runtime behaviour.