Master-detail layout

You are designing or repairing a real interface inside an existing product. Do not start by decorating it.

FIRST, establish the screen job in one sentence: “This screen helps [specific user] understand/do [specific thing] so they can [specific next action].” Inspect the current repository, `design.md`, existing components, tokens, routes, data flow, accessibility behavior, tests, and any supplied reference screenshot before editing. Preserve working product behavior and the project’s existing brand language unless the task explicitly replaces it.

Use the Morten A. Giraffe UI/UX field-guide principles as constraints: purpose before polish, visible hierarchy, relationship-driven spacing, meaningful contrast, clear proximity, behavioral consistency, familiar interaction patterns, reachable targets, structured choice, chunking, progressive disclosure, immediate feedback, recoverable errors, accessibility, responsive purpose, deliberate sequence, trust near doubt, and outcome-based measurement.

ANTI-AI-SLOPE RULES: do not default to generic SaaS composition, random gradients, glow effects, glassmorphism, oversized rounded cards, cards-inside-cards, decorative icon circles, fake stats, fake testimonials, meaningless bento grids, excessive pills, filler copy, giant empty spacing, or animation that does not explain state. Do not invent proof, customer names, metrics, security claims, reviews, or product capabilities.

SPECIFIC TASK — MASTER-DETAIL LAYOUT

Build a scannable master list with persistent selection, a detail pane, sensible next/previous keyboard flow and URL/deep-link behavior for the selected item. On mobile, transform to list → detail navigation rather than shrinking three panes together.

Use when: Inbox, ticket, file or review workflows move between adjacent items.

Avoid when: Users rarely need to move among neighboring records.

IMPLEMENTATION CONTRACT
- Use semantic HTML and the project’s existing accessible primitives before creating new ones.
- Keep one clear primary action; visually subordinate secondary and tertiary actions.
- Design the complete state model where relevant: idle, hover/focus, loading, success, empty, partial data, disabled, validation error, server error, offline/retry, and permission/locked.
- Preserve user input after recoverable errors. Explain what happened and the next useful action.
- Make keyboard operation, visible focus, logical tab order, screen-reader naming, contrast, reduced motion, zoom/reflow, and touch targets part of the implementation—not a later patch.
- Treat mobile as the same purpose under different constraints, not a squeezed desktop. Verify narrow phones, tablet, desktop, long content, and 200% zoom.
- Avoid new dependencies unless the existing stack cannot reasonably support the requirement.
- Keep copy specific, human, and useful. Button labels should describe the outcome.
- For public/indexable pages, keep important meaning, links, headings, and metadata available without requiring client JavaScript; preserve truthful canonicals, titles, structured data, and internal links.
- Protect performance: avoid layout shift, oversized media, unnecessary client JavaScript, and effects that hurt responsiveness.
- Do not silently remove routes, integrations, analytics, auth behavior, deep links, metadata, or existing functionality.
- Run the project’s relevant build, typecheck, lint, tests, and targeted browser checks after implementation. Fix issues caused by your changes.

BEFORE CALLING IT COMPLETE, report: (1) page/screen job, (2) files changed, (3) what was preserved, (4) UX rules applied, (5) responsive/accessibility states verified, (6) tests/checks run with results, (7) remaining unknowns or production-only checks. Never claim “bug free,” “fully accessible,” or “regression free” without evidence.

Source: Morten A. Giraffe UI Prompt Field Guide — https://www.mortenagiraffe.com/journal/ui-prompt-library-for-vibe-coders/08-03-master-detail-layout