Build your own Sleep Cycle.

# Build an original app inspired by Sleep Cycle

You are an experienced mobile product designer and mobile 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: Android. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original native Android sleep routine app called Nightnote, inspired by the diary and alarm workflow of Sleep Cycle. It is for people recording bedtime, wake time, and their own morning observations. The primary journey is setting an alarm, logging a night, stopping the alarm, and reviewing a truthful diary. Scope sleep information to user-entered or explicitly timed records; do not fabricate sleep stages, snoring detection, or sensor-based sleep quality.

## Design
Use an original dim bedtime interface with readable clock controls, a prominent alarm status, and a simple morning diary. Keep snooze and dismiss actions distinct and accessible. Show whether an alarm is scheduled, permission-blocked, or canceled. Charts must label time in bed as time in bed rather than measured sleep. Support TalkBack, large text, system dark mode, and low-motion transitions.

## Features
1. Alarm setup: choose a local wake time and repeat weekdays, select an original bundled sound, and preview it. Request the applicable alarm/notification access in context. Confirm success only after scheduling succeeds; show an actionable unavailable state if required permission is denied.

2. Alarm lifecycle: implement a real Android alarm receiver and supported ringing experience with snooze/dismiss, cancellation, reboot rescheduling, and a single active ringing instance. Follow current restrictions on exact alarms, foreground services, and full-screen notifications; avoid unsupported guarantees.

3. Night journal: start a bedtime record or manually enter a past night, record wake time, optional awake minutes, notes, and self-reported mood. Validate chronological order, overnight spans, and duplicate nights; permit correction without overwriting another record.

4. Trends: display recorded time-in-bed and user-reported duration trends for a week/month, with sample-count and missing-day context. Keep self-reported mood separate from measured values. Do not infer medical conditions or grade health from an invented score.

5. Offline controls: keep diary and alarm settings local, offer CSV/JSON exports, and let users delete records. Stop an alarm and cancel future schedules when disabled; explain that force-stop, device shutdown, or denied permissions may prevent delivery.

## Tech stack
Use Kotlin, Jetpack Compose, Room, AlarmManager, and platform notification/audio APIs in a real Android Studio project. Choose and document an exact-alarm permission strategy appropriate to an alarm app after checking current official Android guidance. Verify delivery using OS-managed scheduling rather than a UI timer or WorkManager exact timing. Include boot/time-zone handling and manifest requirements. Keep diary math separate from scheduling. Never implement the target as a mobile webpage or WebView.

## Data & behavior
Alarm {id, localTime, repeatDays, timeZonePolicy, enabled, soundId, nextTrigger, scheduleState}; RingingInstance {id, alarmId, triggerAt, state, snoozeUntil}; NightEntry {id, bedAt, wokeAt, timeZone, reportedAwakeMinutes, mood, notes, source}; ReminderPreference. Store instants with a zone for diary records and civil-time rules for repeating alarms. Update schedules idempotently when editing settings, track schedule failures, and preserve the prior diary during migrations.

Acceptance checks and scope:
Schedule a short alarm on a real Android device, lock the screen, snooze, dismiss, and verify one ringing instance. Test denied/revoked alarm access, Doze, reboot, force-stop limitations, daylight-saving changes, edited repeats, and an overnight diary entry. Build and test native scheduling; explicitly report any unavailable device verification. Exclude sleep-stage detection, microphone recording, smart wake windows based on alleged stages, health diagnoses, wearables, and copying proprietary analysis.

## 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.