Problem Solving & Design 44

The app is cleanly structured with purposeful empty states, filter badges, and a card layout that communicates listened status through dashed borders and strikethrough text.

• +Listened episodes receive a visually distinct treatment combining a dashed border, muted background, and strikethrough title.
• +Each filter view has its own tailored empty-state copy and a shortcut button to return to the full list.
• +The add form resets and returns focus to the first field after a successful submission, keeping keyboard users in flow.
• -The card layout switches from a single-column to a multi-column grid at the `sm` breakpoint, but there is no intermediate adaptation between mobile and desktop widths — the action buttons stack awkwardly at mid-range viewport sizes.
• -Focus ring styles rely on `focus-visible:ring-2` applied inside the button variant, but no equivalent is defined for the episode card's draggable `<li>` element, leaving keyboard drag initiation without a visible indicator.

Completeness 88

All seven required features are implemented end-to-end, with localStorage persistence, filtering, drag-and-drop reordering, and a two-step delete confirmation.

• +The delete flow requires a confirmation step before committing, preventing accidental removals.
• +Filter chips show live counts for each bucket, so users always know how many episodes are in each view.
• +The queue hook surfaces a notice when localStorage is blocked, warning the user that episodes will not persist.

Technical Craft 92

Domain logic is fully separated into pure, well-tested modules with immutable operations, robust input sanitisation, and a normalisation layer that repairs or drops corrupt localStorage data.

• +sanitizeText replaces invisible and zero-width characters rather than stripping them silently, preventing smuggled content from collapsing adjacent visible characters.
• +normalizeQueue rebuilds every record through the same validation path as the add form, so hand-edited localStorage cannot bypass field requirements or length caps.
• +The remove animation respects the user's reduced-motion preference by skipping the exit delay entirely.
• +reorderEpisodes validates integer bounds and returns an unchanged copy for no-op or out-of-range moves, so callers never need to guard boundaries themselves.