Build your own GeoGuessr.

# Build an original game inspired by GeoGuessr

You are an experienced game designer and gameplay engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: Web. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original browser geography game called Placefinder, inspired by the photo-to-location guessing loop of GeoGuessr. Use a curated collection of original or explicitly permitted geotagged photographs and five-round practice sessions. Players inspect a photograph, place a map marker, submit a guess, and see distance and score. Do not scrape Street View, reuse commercial game locations, or copy its interface.

## Design
Use an original split photo/map layout that stacks on small screens, with zoomable photos, a visible selected guess, round counter, submit confirmation, score, pause, and restart. Provide a text latitude/longitude input as an accessible alternative to map clicks. Keep required map/provider attribution visible in every layout.

## Features
1. Photo collection: author a bounded dataset of permitted photos with verified coordinates, attribution/license records, and short reveal captions. Remove unnecessary identifying metadata and validate latitude/longitude ranges before including a location.

2. Round selection: choose five distinct locations with a seeded schedule, keep one active photo per round, and preserve the same sequence after reload. Give practice sessions a clear restart option rather than pretending to operate a daily competition.

3. Guessing: let the player set and adjust a map marker or enter coordinates, then submit once. Lock the guess and reveal the original location, distance, and an explanation only after submission.

4. Scoring: compute great-circle distance using a tested geographic function and an original documented capped score formula. Handle longitude wrapping, poles, and identical locations; show the round breakdown and total.

5. Session and files: pause/resume, confirm restart, save completed rounds and the current guess, and export/import validated local progress. Provide clear missing-photo and unavailable-map states without silently substituting a different location.

## Tech stack
Use TypeScript with a browser photo viewer, a properly configured map library/provider, and a pure deterministic round/scoring engine separate from the UI. Supply owned or licensed photographs locally. Document provider keys, attribution, usage limits, and any paid dependencies; use an accessible coordinate fallback when map configuration is absent. Do not load unauthorized panoramas or remove attribution.

## Data & behavior
Location {id, photoAssetId, latitude, longitude, caption, attribution, permissionRecord}; Session {seed, locationIds, currentRound, pendingGuess, submittedRounds, status}; RoundResult {locationId, guess, distanceKm, score}; Settings. Local coordinates are inspectable, so label the game as casual practice and exclude anti-cheat claims.

Acceptance checks and scope:
Test zero distance, opposite sides of the date line, polar coordinates, duplicate-round prevention, double submission, missing images, offline map failure, attribution visibility, and reload before/after reveal. Confirm every photo has a recorded permitted source. Exclude unauthorized Street View scraping, copied location packs, multiplayer duels, and global competitive rankings.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.