Merge pull request 'added support for setting start time of sleep entry' (#44) from fix(#43)--enable-editing-sleep-entries into main

Reviewed-on: #44

.gitea/workflows/refresh_showcase_data.yml

@@ -0,0 +1,43 @@
+name: Refresh Showcase Data
+
+on:
+  schedule:
+    # Run daily at 3 AM UTC
+    - cron: "0 3 * * *"
+  workflow_dispatch: # Allow manual triggering
+
+jobs:
+  refresh-data:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ vars.PYTHON_VERSION }}
+
+      - name: Install uv
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+
+      - name: Install dependencies
+        run: |
+          uv sync --no-dev --all-extras
+
+      - name: Run showcase data seeding script
+        env:
+          ADMIN_USERNAME: ${{ secrets.ADMIN_USERNAME }}
+          ADMIN_PASSWORD: ${{ secrets.ADMIN_PASSWORD }}
+          POSTGRES_URI: ${{ secrets.POSTGRES_URI }}
+        run: |
+          uv run python scripts/seed_showcase_data.py
+
+      - name: Notify on success
+        if: success()
+        run: echo "✅ Showcase data refreshed successfully"
+
+      - name: Notify on failure
+        if: failure()
+        run: echo "❌ Failed to refresh showcase data"

docker-compose.prod.yml

@@ -34,7 +34,7 @@ services:
       interval: 10s
       timeout: 5s
       retries: 5
-      start_period: 1s
+      start_period: 3s
   postgres:
     image: postgres:14-alpine
     environment:

pyproject.toml

@@ -41,7 +41,7 @@ dev = [
 
 [[tool.uv.index]]
 name = "threadripper-proxpi-cache"
-url = "http://10.0.0.2:5001/index/"
+url = "http://10.184.20.2:5001/index/"
 default = true
 
 [tool.mypy]
@@ -71,3 +71,7 @@ markers = [
 [[tool.mypy.overrides]]
 module = "redis.*"
 ignore_missing_imports = true
+
+[[tool.mypy.overrides]]
+module = "showcase_data_definitions.*"
+ignore_missing_imports = true

scripts/seed_showcase_data.py

@@ -0,0 +1,185 @@
+"""Seed test data into the database for demo purposes."""
+
+import sys
+from pathlib import Path
+from datetime import datetime
+
+# Add parent directory to path to import baby_monitor modules
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+# Import after path is set up
+from baby_monitor.repositories.dependencies.get_database import (  # noqa: E402
+    get_database,
+    init_db,
+)
+from baby_monitor.repositories.user.sqlite_user import (  # noqa: E402
+    DatabaseUserRepository,
+)
+from baby_monitor.repositories.child.sqlite_child import (  # noqa: E402
+    DatabaseChildRepository,
+)
+from baby_monitor.repositories.feeding.sqlite_feeding import (  # noqa: E402
+    DatabaseFeedingRepository,
+)
+from baby_monitor.repositories.diaper_change.sqlite_diaper_change import (  # noqa: E402, E501
+    DatabaseDiaperChangeRepository,
+)
+from baby_monitor.repositories.sleep.sqlite_sleep import (  # noqa: E402
+    DatabaseSleepRepository,
+)
+from baby_monitor.routers.auth import hash_password  # noqa: E402
+from showcase_data_definitions import generate_showcase_data  # noqa: E402
+
+
+def seed_database(reference_time: datetime | None = None) -> None:
+    """
+    Seed the database with test data.
+
+    This function is idempotent - it will check if test users exist
+    and either create them or update timestamps of existing data.
+
+    Args:
+        reference_time: The "now" time to use for generating timestamps.
+            Defaults to current time.
+    """
+    # Initialize database
+    init_db()
+    db = next(get_database())
+
+    try:
+        # Initialize repositories
+        user_repo = DatabaseUserRepository(db)
+        child_repo = DatabaseChildRepository(db)
+        feeding_repo = DatabaseFeedingRepository(db)
+        diaper_repo = DatabaseDiaperChangeRepository(db)
+        sleep_repo = DatabaseSleepRepository(db)
+
+        # Generate showcase data
+        test_data = generate_showcase_data(reference_time)
+
+        print("Starting database seeding...")
+        print(f"Reference time: {test_data['reference_time']}")
+
+        # Create or get showcase users
+        user_ids = []
+        for user_data in test_data["users"]:
+            # Check if user exists
+            existing_user = user_repo.get_by_username(user_data["username"])
+
+            if existing_user:
+                print(f"✓ User '{user_data['username']}' already exists")
+                user_ids.append(existing_user["id"])
+            else:
+                # Create new user
+                hashed_pw = hash_password(user_data["password"])
+                user_id = user_repo.create(
+                    username=user_data["username"],
+                    hashed_password=hashed_pw,
+                )
+                user_ids.append(user_id["id"])
+                print(f"✓ Created user '{user_data['username']}'")
+
+        # Create or get shared child
+        child_data = test_data["child"]
+
+        # Check if child exists for first user
+        existing_children = child_repo.get_by_user_id(user_ids[0])
+        child_id: int | None = None
+
+        # Look for existing child with matching name
+        for child in existing_children:
+            if child["name"] == child_data["name"]:
+                child_id = child["id"]
+                print(f"✓ Child '{child_data['name']}' already exists")
+                break
+
+        if child_id is None:
+            # Create new child
+            created_child = child_repo.create(
+                name=child_data["name"],
+                birth_time=child_data["birth_time"],
+                birth_weight=child_data["birth_weight"],
+                user_id=user_ids[0],
+            )
+            child_id = created_child["id"]
+            print(f"✓ Created child '{child_data['name']}'")
+
+        # Ensure child_id is set
+        assert child_id is not None, "Child ID must be set at this point"
+
+        # Share child with second user if not already shared
+        parent_ids = child_repo.get_parent_ids(child_id)
+        if user_ids[1] not in parent_ids:
+            child_repo.add_parent(child_id, user_ids[1])
+            msg = f"✓ Shared child with '{test_data['users'][1]['username']}'"
+            print(msg)
+
+        # Clear existing logs to avoid duplicates
+        print("Clearing existing logs...")
+
+        # Get all logs for this child
+        existing_feedings = feeding_repo.get_by_child_id(child_id)
+        for feeding in existing_feedings:
+            feeding_repo.delete(feeding["id"])
+
+        existing_diapers = diaper_repo.get_by_child_id(child_id)
+        for diaper in existing_diapers:
+            diaper_repo.delete(diaper["id"])
+
+        existing_sleep = sleep_repo.get_by_child_id(child_id)
+        for sleep in existing_sleep:
+            sleep_repo.delete(sleep["id"])
+
+        print("✓ Cleared existing logs")
+
+        # Add feeding logs
+        print(f"Adding {len(test_data['feedings'])} feeding logs...")
+        for feeding in test_data["feedings"]:
+            feeding_repo.create(
+                child_id=child_id,
+                start_time=feeding["start_time"],
+                end_time=feeding["end_time"],
+                feeding_type=feeding["feeding_type"],
+            )
+        print(f"✓ Added {len(test_data['feedings'])} feedings")
+
+        # Add diaper changes
+        print(f"Adding {len(test_data['diapers'])} diaper changes...")
+        for diaper in test_data["diapers"]:
+            diaper_repo.create(
+                child_id=child_id,
+                change_time=diaper["time"],
+                poop_color=diaper.get("poop_color"),
+                poop_amount=diaper.get("poop_amount"),
+                pee_color=diaper.get("pee_color"),
+                pee_amount=diaper.get("pee_amount"),
+            )
+        print(f"✓ Added {len(test_data['diapers'])} diaper changes")
+
+        # Add sleep sessions
+        print(f"Adding {len(test_data['sleep'])} sleep sessions...")
+        for sleep in test_data["sleep"]:
+            sleep_repo.create(
+                child_id=child_id,
+                start_time=sleep["start_time"],
+                end_time=sleep["end_time"],
+            )
+        print(f"✓ Added {len(test_data['sleep'])} sleep sessions")
+
+        db.commit()
+        print("\n✅ Database seeding completed successfully!")
+        print("\nTest user credentials:")
+        print(f"  Username: {test_data['users'][0]['username']}")
+        print(f"  Password: {test_data['users'][0]['password']}")
+        print("  (Both users share the same password)")
+
+    except Exception as e:
+        db.rollback()
+        print(f"\n❌ Error seeding database: {e}")
+        raise
+    finally:
+        db.close()
+
+
+if __name__ == "__main__":
+    seed_database()

scripts/showcase_data_definitions.py

@@ -0,0 +1,278 @@
+"""Definition of showcase data to be used for presenting the app."""
+
+from datetime import datetime, timedelta
+import random
+
+# User credentials
+SHOWCASE_USERS = [
+    {
+        "username": "user",
+        "password": "demo123",  # Will be hashed when inserted
+    },
+    {
+        "username": "user2",
+        "password": "demo123",  # Will be hashed when inserted
+    },
+]
+
+# Shared child (14 days old)
+CHILD_AGE_DAYS = 14
+
+
+def get_child_data(reference_time: datetime) -> dict:
+    """Get child data with birth time relative to reference time."""
+    birth_time = reference_time - timedelta(days=CHILD_AGE_DAYS)
+    return {
+        "name": "Emma Rose",
+        "birth_time": birth_time,
+        "birth_weight": 3420,  # grams (7.5 lbs)
+    }
+
+
+def get_feeding_schedule(reference_time: datetime) -> list[dict]:
+    """
+    Generate realistic feeding schedule for the last 14 days.
+
+    Newborns feed every 2-3 hours initially, gradually spacing out
+    to 3-4 hours.
+    """
+    feedings: list[dict] = []
+    current_time = reference_time - timedelta(days=CHILD_AGE_DAYS)
+    end_time = reference_time
+
+    feeding_types = ["left_breast", "right_breast", "bottle"]
+
+    # Day-by-day feeding patterns
+    day_number = 0
+    while current_time < end_time:
+        age_in_days = day_number
+
+        # Newborns feed more frequently
+        if age_in_days < 3:
+            interval_hours = random.uniform(2, 2.5)
+            duration_minutes = random.randint(15, 25)
+        elif age_in_days < 7:
+            interval_hours = random.uniform(2.5, 3)
+            duration_minutes = random.randint(20, 30)
+        else:
+            interval_hours = random.uniform(3, 3.5)
+            duration_minutes = random.randint(20, 35)
+
+        # Alternate between breasts and occasional bottle
+        if random.random() < 0.2:  # 20% bottle feeding
+            feeding_type = "bottle"
+        else:
+            # Alternate breasts
+            feeding_type = feeding_types[len(feedings) % 2]
+
+        start_time = current_time
+        end_time_feeding = start_time + timedelta(minutes=duration_minutes)
+
+        feedings.append(
+            {
+                "start_time": start_time,
+                "end_time": end_time_feeding,
+                "feeding_type": feeding_type,
+            }
+        )
+
+        current_time += timedelta(hours=interval_hours)
+
+        # Move to next day
+        prev_date = (current_time - timedelta(hours=interval_hours)).date()
+        if current_time.date() != prev_date:
+            day_number += 1
+
+    return feedings
+
+
+def get_diaper_changes(reference_time: datetime) -> list[dict]:
+    """
+    Generate realistic diaper changes for the last 14 days.
+
+    - First 2-3 days: Black/dark (meconium), minimal pee
+    - Days 3-5: Transition to yellow, more frequent
+    - Days 5+: Regular yellow stools, normal pee patterns
+    - 8-10 diaper changes per day initially, settling to 6-8
+    """
+    diapers = []
+    current_time = reference_time - timedelta(days=CHILD_AGE_DAYS)
+    end_time = reference_time
+
+    day_number = 0
+
+    while current_time < end_time:
+        age_in_days = day_number
+
+        # Determine number of diaper changes per day based on age
+        if age_in_days < 3:
+            changes_per_day = random.randint(8, 10)
+        elif age_in_days < 7:
+            changes_per_day = random.randint(7, 9)
+        else:
+            changes_per_day = random.randint(6, 8)
+
+        # Distribute changes throughout the day
+        day_start = current_time.replace(hour=0, minute=0, second=0, microsecond=0)
+        day_end = day_start + timedelta(days=1)
+
+        for _ in range(changes_per_day):
+            # Random time during the day
+            random_seconds = random.randint(0, 86400)
+            change_time = day_start + timedelta(seconds=random_seconds)
+
+            if change_time >= end_time:
+                break
+
+            # Determine diaper contents
+            has_poop = random.random() < 0.4  # 40% have poop
+            # 90% have pee, or always if no poop
+            has_pee = random.random() < 0.9 or not has_poop
+
+            diaper = {
+                "time": change_time,
+                "has_poop": has_poop,
+                "has_pee": has_pee,
+            }
+
+            # Poop characteristics based on age
+            if has_poop:
+                if age_in_days < 2:
+                    # Meconium phase
+                    diaper["poop_color"] = "black"
+                    diaper["poop_amount"] = "light"
+                elif age_in_days < 4:
+                    # Transition phase
+                    colors = ["black", "green", "yellow"]
+                    diaper["poop_color"] = random.choice(colors)
+                    amounts = ["light", "medium"]
+                    diaper["poop_amount"] = random.choice(amounts)
+                else:
+                    # Normal phase
+                    colors = ["yellow", "yellow", "yellow", "green"]
+                    diaper["poop_color"] = random.choice(colors)
+                    # Amount increases with age
+                    if age_in_days < 7:
+                        amounts = ["light", "medium"]
+                        diaper["poop_amount"] = random.choice(amounts)
+                    else:
+                        amounts = ["medium", "heavy"]
+                        diaper["poop_amount"] = random.choice(amounts)
+
+            # Pee characteristics based on age
+            if has_pee:
+                if age_in_days < 2:
+                    # Very light pee initially
+                    diaper["pee_amount"] = "light"
+                    diaper["pee_color"] = random.choice(["clear", "yellow"])
+                elif age_in_days < 5:
+                    # Increasing output
+                    diaper["pee_amount"] = random.choice(["light", "medium"])
+                    diaper["pee_color"] = random.choice(["clear", "yellow"])
+                else:
+                    # Normal output
+                    if age_in_days < 10:
+                        amounts = ["medium", "medium", "heavy"]
+                        diaper["pee_amount"] = random.choice(amounts)
+                    else:
+                        amounts = ["medium", "heavy", "heavy"]
+                        diaper["pee_amount"] = random.choice(amounts)
+                    colors = ["clear", "yellow", "yellow"]
+                    diaper["pee_color"] = random.choice(colors)
+
+            diapers.append(diaper)
+
+        day_number += 1
+        current_time = day_end
+
+    # Sort by time (type: ignore for mypy - we know time is datetime)
+    diapers.sort(
+        key=lambda x: x["time"]  # type: ignore[arg-type,return-value]
+    )
+    return diapers
+
+
+def get_sleep_sessions(reference_time: datetime) -> list[dict]:
+    """
+    Generate realistic sleep patterns for the last 14 days.
+
+    Newborns sleep 16-18 hours per day in short bursts (30min - 4 hours).
+    Sleep gradually consolidates over time.
+    """
+    sleep_sessions = []
+    current_time = reference_time - timedelta(days=CHILD_AGE_DAYS)
+    end_time = reference_time
+
+    day_number = 0
+
+    while current_time < end_time:
+        age_in_days = day_number
+
+        # Sleep patterns evolve with age
+        if age_in_days < 3:
+            # Very short, frequent naps
+            avg_wake_time = 1.5  # hours
+            sleep_duration_range = (30, 120)  # minutes
+        elif age_in_days < 7:
+            # Slightly longer sleep periods
+            avg_wake_time = 2
+            sleep_duration_range = (45, 180)
+        else:
+            # More consolidated sleep
+            avg_wake_time = 2.5
+            sleep_duration_range = (60, 240)
+
+        # Random wake time with variation
+        wake_minutes = random.randint(int(avg_wake_time * 45), int(avg_wake_time * 75))
+
+        # Sleep start time
+        start_time = current_time + timedelta(minutes=wake_minutes)
+
+        if start_time >= end_time:
+            break
+
+        # Sleep duration
+        duration_minutes = random.randint(*sleep_duration_range)
+
+        # Longer sleep at night
+        if 20 <= start_time.hour or start_time.hour < 6:
+            duration_minutes = int(duration_minutes * 1.3)
+
+        end_time_sleep = start_time + timedelta(minutes=duration_minutes)
+
+        sleep_sessions.append(
+            {
+                "start_time": start_time,
+                "end_time": end_time_sleep,
+            }
+        )
+
+        current_time = end_time_sleep
+        birth_time = reference_time - timedelta(days=CHILD_AGE_DAYS)
+        day_number = (current_time - birth_time).days
+
+    return sleep_sessions
+
+
+def generate_showcase_data(reference_time: datetime | None = None) -> dict:
+    """
+    Generate all test data with timestamps relative to reference time.
+
+    Args:
+        reference_time: The "now" time to use as reference.
+            Defaults to current time.
+
+    Returns:
+        Dictionary containing all test data
+    """
+    if reference_time is None:
+        reference_time = datetime.now()
+
+    return {
+        "users": SHOWCASE_USERS,
+        "child": get_child_data(reference_time),
+        "feedings": get_feeding_schedule(reference_time),
+        "diapers": get_diaper_changes(reference_time),
+        "sleep": get_sleep_sessions(reference_time),
+        "reference_time": reference_time,
+    }

src/baby_monitor/main.py

@@ -119,6 +119,12 @@ def serve_sleep() -> FileResponse:
     return FileResponse(static_path / "sleep.html")
 
 
+@app.get("/log-sleep.html", include_in_schema=False)
+def serve_log_sleep() -> FileResponse:
+    """Serve the log sleep page."""
+    return FileResponse(static_path / "log-sleep.html")
+
+
 @app.get("/settings.html", include_in_schema=False)
 def serve_settings() -> FileResponse:
     """Serve the settings page."""
@@ -137,6 +143,24 @@ def serve_menu_js() -> FileResponse:
     return FileResponse(static_path / "menu.js")
 
 
+@app.get("/dark-mode.css", include_in_schema=False)
+def serve_dark_mode_css() -> FileResponse:
+    """Serve the dark mode CSS."""
+    return FileResponse(static_path / "dark-mode.css")
+
+
+@app.get("/theme-init.js", include_in_schema=False)
+def serve_theme_init_js() -> FileResponse:
+    """Serve the theme initialization JavaScript."""
+    return FileResponse(static_path / "theme-init.js")
+
+
+@app.get("/chart-theme.js", include_in_schema=False)
+def serve_chart_theme_js() -> FileResponse:
+    """Serve the chart theming JavaScript."""
+    return FileResponse(static_path / "chart-theme.js")
+
+
 @app.get("/api/")
 def read_root(token: Annotated[str, Depends(verify_token)]) -> dict:
     """API root endpoint (requires authentication)."""

src/baby_monitor/models/child.py

@@ -20,3 +20,5 @@ class ChildResponse(BaseModel):
     birth_time: datetime
     birth_weight: float
     created_at: datetime
+    parent_count: int | None = None
+    parent_usernames: list[str] | None = None

src/baby_monitor/models/sleep.py

@@ -9,11 +9,13 @@ class CreateSleepRequest(BaseModel):
 
     child_id: int = Field(..., gt=0)
     start_time: datetime
+    end_time: datetime | None = None
 
 
 class UpdateSleepRequest(BaseModel):
     """Request model for updating a sleep log."""
 
+    start_time: datetime | None = None
     end_time: datetime | None = None
 
 

src/baby_monitor/repositories/dependencies/get_token_repository.py

@@ -6,7 +6,7 @@ import logging
 from baby_monitor.repositories.interfaces import (
     TokenRepositoryInterface,
 )
-from baby_monitor.repositories.token.memory_token import (
+from baby_monitor.repositories.token import (
     InMemoryTokenRepository,
 )
 
@@ -43,7 +43,7 @@ def _initialize_token_repository() -> TokenRepositoryInterface:
         ) from e
 
     try:
-        from baby_monitor.repositories.token.redis_token import (
+        from baby_monitor.repositories.token import (
             RedisTokenRepository,
         )
 

src/baby_monitor/repositories/interfaces/sleep_repository_interface.py

@@ -12,6 +12,7 @@ class SleepRepositoryInterface(ABC):
         self,
         child_id: int,
         start_time: datetime,
+        end_time: datetime | None = None,
     ) -> dict:
         """Create a new sleep log entry."""
 
@@ -31,6 +32,7 @@ class SleepRepositoryInterface(ABC):
     def update(
         self,
         sleep_id: int,
+        start_time: datetime | None = None,
         end_time: datetime | None = None,
     ) -> dict | None:
         """Update a sleep log entry."""

src/baby_monitor/repositories/sleep/sqlite_sleep.py

@@ -27,12 +27,13 @@ class DatabaseSleepRepository(SleepRepositoryInterface):
         self,
         child_id: int,
         start_time: datetime,
+        end_time: datetime | None = None,
     ) -> dict:
         """Create a new sleep log entry."""
         sleep = Sleep(
             child_id=child_id,
             start_time=start_time,
-            end_time=None,
+            end_time=end_time,
         )
         self.db.add(sleep)
         self.db.commit()
@@ -72,6 +73,7 @@ class DatabaseSleepRepository(SleepRepositoryInterface):
     def update(
         self,
         sleep_id: int,
+        start_time: datetime | None = None,
         end_time: datetime | None = None,
     ) -> dict | None:
         """Update a sleep log entry."""
@@ -79,6 +81,8 @@ class DatabaseSleepRepository(SleepRepositoryInterface):
         if not sleep:
             return None
 
+        if start_time is not None:
+            sleep.start_time = start_time  # type: ignore[assignment]
         if end_time is not None:
             sleep.end_time = end_time  # type: ignore[assignment]
 

src/baby_monitor/repositories/token/__init__.py

@@ -0,0 +1,11 @@
+"""Token repository implementations and configurations."""
+
+from .default_ttl import DEFAULT_TTL
+from .memory_token import InMemoryTokenRepository
+from .redis_token import RedisTokenRepository
+
+__all__ = [
+    "DEFAULT_TTL",
+    "InMemoryTokenRepository",
+    "RedisTokenRepository",
+]

src/baby_monitor/repositories/token/default_ttl.py

@@ -0,0 +1,3 @@
+"""Definition of Token default TTL."""
+
+DEFAULT_TTL = 28800  # seconds -> 8 hours

src/baby_monitor/repositories/token/memory_token.py

@@ -3,6 +3,7 @@
 from datetime import datetime, timedelta, UTC
 
 from baby_monitor.repositories.interfaces import TokenRepositoryInterface
+from baby_monitor.repositories.token import DEFAULT_TTL
 
 
 class InMemoryTokenRepository(TokenRepositoryInterface):
@@ -17,13 +18,16 @@ class InMemoryTokenRepository(TokenRepositoryInterface):
         # token -> (user_id, expiry_time)
         self._tokens: dict[str, tuple[int, datetime]] = {}
 
-    def store(self, token: str, user_id: int, ttl: int = 3600) -> None:
+    def store(self, token: str, user_id: int, ttl: int = DEFAULT_TTL) -> None:
         """Store a token with TTL (time to live in seconds)."""
         expiry = datetime.now(UTC) + timedelta(seconds=ttl)
         self._tokens[token] = (user_id, expiry)
 
     def verify(self, token: str) -> int | None:
-        """Verify token and return user_id if valid, None otherwise."""
+        """Verify token and return user_id if valid, None otherwise.
+
+        Implements sliding expiration: extends token lifetime on each verification.
+        """
         if token not in self._tokens:
             return None
 
@@ -34,6 +38,10 @@ class InMemoryTokenRepository(TokenRepositoryInterface):
             del self._tokens[token]
             return None
 
+        # Sliding expiration: extend the token lifetime
+        new_expiry = datetime.now(UTC) + timedelta(seconds=DEFAULT_TTL)
+        self._tokens[token] = (user_id, new_expiry)
+
         return user_id
 
     def invalidate(self, token: str) -> None:

src/baby_monitor/repositories/token/redis_token.py

@@ -3,14 +3,14 @@
 from typing import Any
 
 from baby_monitor.repositories.interfaces import TokenRepositoryInterface
+from baby_monitor.repositories.token import DEFAULT_TTL
 
 
 class RedisTokenRepository(TokenRepositoryInterface):
     """
     Redis-based token storage.
 
-    Requires redis package: pip install redis
-    Set REDIS_URI environment variable (e.g., redis://localhost:6379/0)
+    This implementation uses Redis to store tokens with TTL. Implements sliding expiration.
     """
 
     def __init__(self, redis_client: Any) -> None:
@@ -22,16 +22,21 @@ class RedisTokenRepository(TokenRepositoryInterface):
         """
         self.redis = redis_client
 
-    def store(self, token: str, user_id: int, ttl: int = 3600) -> None:
+    def store(self, token: str, user_id: int, ttl: int = DEFAULT_TTL) -> None:
         """Store a token with TTL (time to live in seconds)."""
         key = f"token:{token}"
         self.redis.setex(key, ttl, str(user_id))
 
     def verify(self, token: str) -> int | None:
-        """Verify token and return user_id if valid, None otherwise."""
+        """Verify token and return user_id if valid, None otherwise.
+
+        Implements sliding expiration: extends token lifetime on verification.
+        """
         key = f"token:{token}"
         user_id_str = self.redis.get(key)
         if user_id_str:
+            # Sliding expiration: extend the token lifetime
+            self.redis.expire(key, DEFAULT_TTL)
             return int(user_id_str)
         return None
 

src/baby_monitor/routers/child.py

@@ -11,10 +11,12 @@ from baby_monitor.routers.auth import verify_token
 from baby_monitor.repositories.interfaces import (
     ChildRepositoryInterface,
     ChildInvitationRepositoryInterface,
+    UserRepositoryInterface,
 )
 from baby_monitor.repositories.dependencies import (
     get_child_repository,
     get_child_invitation_repository,
+    get_user_repository,
 )
 
 router = APIRouter(prefix="/api/children", tags=["children"])
@@ -62,10 +64,29 @@ def create_child(
 def get_user_children(
     user_id: Annotated[int, Depends(verify_token)],
     child_repo: Annotated[ChildRepositoryInterface, Depends(get_child_repository)],
+    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
 ) -> list[ChildResponse]:
     """Get all children for the authenticated user."""
     children = child_repo.get_by_user_id(user_id)
-    return [ChildResponse(**child) for child in children]
+
+    # Add parent information to each child
+    result = []
+    for child in children:
+        child_data = child.copy()
+        parent_ids = child_repo.get_parent_ids(child["id"])
+        child_data["parent_count"] = len(parent_ids)
+
+        # Get usernames of all parents
+        parent_usernames = []
+        for parent_id in parent_ids:
+            parent = user_repo.get_by_id(parent_id)
+            if parent:
+                parent_usernames.append(parent["username"])
+        child_data["parent_usernames"] = parent_usernames
+
+        result.append(ChildResponse(**child_data))
+
+    return result
 
 
 @router.get("/{child_id}", response_model=ChildResponse)

src/baby_monitor/routers/health.py

@@ -1,6 +1,7 @@
 """Health check router for monitoring endpoints."""
 
-from fastapi import APIRouter
+import os
+from fastapi import APIRouter, HTTPException
 
 router = APIRouter(tags=["health"])
 
@@ -20,11 +21,53 @@ def readiness_check() -> dict[str, str]:
     """
     Readiness check endpoint for container orchestration.
 
-    Returns 200 if the service is ready to accept traffic.
-    This can include checks for database connectivity, external services, etc.
+    Returns 200 if the service is ready to accept traffic, else 503.
     """
-    # Add dependency checks here if needed (database, cache, etc.)
-    # For now, simple readiness check
+
+    # Determine if configured to use Redis
+    redis_uri = os.getenv("REDIS_URI")
+
+    # If Redis is used, check connectivity
+    if redis_uri:
+        try:
+            import redis
+
+            redis_client = redis.from_url(redis_uri)
+            redis_client.ping()
+        except Exception as exc:
+            raise HTTPException(
+                status_code=503,
+                detail={
+                    "status": "not ready",
+                    "reason": "No connection to Redis",
+                    "exception": str(exc),
+                },
+            ) from exc
+    # Determine if configured to use PostgreSQL
+    postgres_uri = os.getenv("POSTGRES_URI")
+
+    # If PostgreSQL is used, check connectivity
+    if postgres_uri:
+        try:
+            from sqlalchemy import create_engine
+            from sqlalchemy.orm import sessionmaker
+            from sqlalchemy import text
+
+            engine = create_engine(postgres_uri)
+            SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+            with SessionLocal() as db:
+                db.execute(text("SELECT 1"))
+        except Exception as exc:
+            raise HTTPException(
+                status_code=503,
+                detail={
+                    "status": "not ready",
+                    "reason": "No connection to PostgreSQL",
+                    "exception": str(exc),
+                },
+            ) from exc
+
+    # Unable to prove not ready, so assume ready
     return {"status": "ready"}
 
 
@@ -60,9 +103,9 @@ def service_info() -> dict:
     # Check current configuration
     config = {
         "environment": os.getenv("ENVIRONMENT", "production"),
-        "data_dir": os.getenv("DATA_DIR", "/data"),
-        "redis_configured": bool(os.getenv("REDIS_URI")),
     }
+    if not features["postgresql"]:
+        config["data_dir"] = os.getenv("DATA_DIR", "/data")
 
     return {
         "service": "baby-monitor",

src/baby_monitor/routers/sleep.py

@@ -36,6 +36,7 @@ def create_sleep(
     sleep = sleep_repo.create(
         child_id=request.child_id,
         start_time=request.start_time,
+        end_time=request.end_time,
     )
 
     return SleepResponse(**sleep)
@@ -111,6 +112,7 @@ def update_sleep(
 
     updated = sleep_repo.update(
         sleep_id=sleep_id,
+        start_time=request.start_time,
         end_time=request.end_time,
     )
 

src/baby_monitor/static/add-child.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Add Child - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       * {
         margin: 0;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: #667eea;
         min-height: 100vh;
         display: flex;
         justify-content: center;
@@ -33,13 +35,13 @@
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
@@ -51,7 +53,7 @@
       label {
         display: block;
         margin-bottom: 8px;
-        color: #333;
+        color: var(--text-primary);
         font-weight: 600;
         font-size: 14px;
       }
@@ -59,19 +61,22 @@
       input {
         width: 100%;
         padding: 12px;
-        border: 1px solid #ddd;
+        border: 2px solid #ccc;
         border-radius: 6px;
         font-size: 14px;
         transition: border-color 0.2s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
       }
 
       input:focus {
         outline: none;
-        border-color: #667eea;
+        border-color: var(--input-focus-border);
       }
 
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -135,7 +140,7 @@
 
       .help-text {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
         margin-top: 4px;
       }
     </style>
@@ -313,9 +318,9 @@
                 : "Child added successfully!",
               "success",
             );
-            // Redirect to home page after 1 second
+            // Redirect to settings page if editing, otherwise home page
             setTimeout(() => {
-              window.location.href = "/";
+              window.location.href = isEditMode ? "/settings.html" : "/";
             }, 1000);
           } else {
             showMessage(
@@ -338,7 +343,8 @@
       }
 
       function goBack() {
-        window.location.href = "/";
+        // Redirect to settings page if editing, otherwise home page
+        window.location.href = isEditMode ? "/settings.html" : "/";
       }
 
       function skipToHome() {

src/baby_monitor/static/admin.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Baby Monitor - Admin</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       * {
         margin: 0;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: #667eea;
         min-height: 100vh;
         display: flex;
         justify-content: center;
@@ -33,13 +35,13 @@
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
@@ -62,7 +64,8 @@
       }
 
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -95,7 +98,7 @@
         display: none;
         margin-top: 20px;
         padding: 15px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
         border: 2px solid #667eea;
       }
@@ -106,7 +109,7 @@
 
       .link-label {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 8px;
         font-weight: 600;
         text-transform: uppercase;
@@ -121,13 +124,13 @@
       .link-text {
         flex: 1;
         padding: 10px;
-        background: white;
-        border: 1px solid #ddd;
+        background: var(--bg-secondary);
+        border: 1px solid var(--border-color);
         border-radius: 4px;
         font-family: "Courier New", monospace;
         font-size: 13px;
         word-break: break-all;
-        color: #333;
+        color: var(--text-primary);
       }
 
       .copy-button {
@@ -193,7 +196,7 @@
       .search-box {
         width: 100%;
         padding: 10px;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 4px;
         font-size: 14px;
         margin-bottom: 15px;
@@ -202,7 +205,7 @@
       .user-list {
         max-height: 400px;
         overflow-y: auto;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 4px;
       }
 
@@ -211,8 +214,8 @@
         justify-content: space-between;
         align-items: center;
         padding: 12px;
-        border-bottom: 1px solid #eee;
-        background: white;
+        border-bottom: 1px solid var(--border-lighter);
+        background: var(--bg-secondary);
       }
 
       .user-item:last-child {
@@ -220,7 +223,7 @@
       }
 
       .user-item:hover {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
       }
 
       .user-info {
@@ -229,13 +232,13 @@
 
       .user-name {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 4px;
       }
 
       .user-meta {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .admin-badge {
@@ -506,8 +509,8 @@
                 ID: ${user.id} • Created: ${new Date(user.created_at).toLocaleDateString()}
               </div>
             </div>
-            <button 
-              class="delete-user-btn" 
+            <button
+              class="delete-user-btn"
               onclick="showDeleteModal(${user.id}, '${user.username}', ${user.is_admin})"
               ${user.is_admin ? 'disabled title="Cannot delete admin users"' : ""}
             >

src/baby_monitor/static/chart-theme.js

@@ -0,0 +1,207 @@
+/* Chart.js Dark Mode Helper
+ * Provides theme-aware color palettes and chart options for Chart.js
+ * Usage: Include this before your chart initialization code
+ */
+
+(function () {
+  "use strict";
+
+  // Helper to get effective theme
+  function getEffectiveTheme() {
+    return window.getEffectiveTheme ? window.getEffectiveTheme() : "light";
+  }
+
+  // Get theme-appropriate colors for Chart.js
+  window.getChartColors = function () {
+    const isDark = getEffectiveTheme() === "dark";
+
+    return {
+      // Grid lines
+      grid: isDark ? "rgba(255, 255, 255, 0.1)" : "rgba(0, 0, 0, 0.05)",
+      gridMajor: isDark ? "rgba(255, 255, 255, 0.15)" : "rgba(0, 0, 0, 0.1)",
+
+      // Text colors
+      text: isDark ? "#b0b0b0" : "#666666",
+      textPrimary: isDark ? "#e0e0e0" : "#333333",
+
+      // Data series colors (optimized for background)
+      series: isDark
+        ? [
+            "rgba(139, 158, 255, 0.8)", // Brighter purple
+            "rgba(110, 197, 255, 0.8)", // Brighter blue
+            "rgba(255, 179, 255, 0.8)", // Brighter pink
+            "rgba(129, 199, 132, 0.8)", // Brighter green
+            "rgba(255, 183, 77, 0.8)", // Brighter orange
+            "rgba(156, 107, 184, 0.8)", // Brighter deep purple
+            "rgba(77, 255, 255, 0.8)", // Brighter cyan
+            "rgba(255, 138, 155, 0.8)", // Brighter red
+          ]
+        : [
+            "rgba(102, 126, 234, 0.8)", // Purple
+            "rgba(118, 75, 162, 0.8)", // Deep purple
+            "rgba(255, 159, 64, 0.8)", // Orange
+            "rgba(76, 175, 80, 0.8)", // Green
+            "rgba(244, 67, 54, 0.8)", // Red
+            "rgba(156, 39, 176, 0.8)", // Violet
+            "rgba(102, 126, 234, 0.6)", // Light purple
+            "rgba(118, 75, 162, 0.6)", // Light deep purple
+          ],
+
+      // Solid data colors (for pie charts, etc.)
+      solidSeries: isDark
+        ? [
+            "#8b9eff",
+            "#6ec5ff",
+            "#ffb3ff",
+            "#81c784",
+            "#ffb74d",
+            "#9c6bb8",
+            "#4dffff",
+            "#ff8a9b",
+          ]
+        : [
+            "#667eea",
+            "#764ba2",
+            "#ff9f40",
+            "#4caf50",
+            "#f44336",
+            "#9c27b0",
+            "#667eea",
+            "#764ba2",
+          ],
+
+      // Background colors
+      background: isDark ? "#2d2d2d" : "#f8f9fa",
+    };
+  };
+
+  // Get default Chart.js options with theme support
+  window.getChartOptions = function (customOptions = {}) {
+    const colors = window.getChartColors();
+
+    const defaults = {
+      responsive: true,
+      maintainAspectRatio: false,
+      plugins: {
+        legend: {
+          labels: {
+            color: colors.text,
+            font: {
+              size: 12,
+            },
+          },
+        },
+        tooltip: {
+          backgroundColor:
+            getEffectiveTheme() === "dark" ? "#3a3a3a" : "#ffffff",
+          titleColor: colors.textPrimary,
+          bodyColor: colors.text,
+          borderColor: colors.grid,
+          borderWidth: 1,
+        },
+      },
+      scales: {},
+    };
+
+    // Deep merge customOptions with defaults
+    return mergeDeep(defaults, customOptions);
+  };
+
+  // Get theme-appropriate scale options
+  window.getChartScaleOptions = function (axis = "x", customOptions = {}) {
+    const colors = window.getChartColors();
+
+    const defaults = {
+      grid: {
+        color: colors.grid,
+        borderColor: colors.gridMajor,
+      },
+      ticks: {
+        color: colors.text,
+        font: {
+          size: 12,
+        },
+      },
+      title: {
+        color: colors.textPrimary,
+        font: {
+          size: 13,
+          weight: "600",
+        },
+      },
+    };
+
+    return mergeDeep(defaults, customOptions);
+  };
+
+  // Helper function to deep merge objects
+  function mergeDeep(target, source) {
+    const output = Object.assign({}, target);
+    if (isObject(target) && isObject(source)) {
+      Object.keys(source).forEach((key) => {
+        if (isObject(source[key])) {
+          if (!(key in target)) {
+            Object.assign(output, { [key]: source[key] });
+          } else {
+            output[key] = mergeDeep(target[key], source[key]);
+          }
+        } else {
+          Object.assign(output, { [key]: source[key] });
+        }
+      });
+    }
+    return output;
+  }
+
+  function isObject(item) {
+    return item && typeof item === "object" && !Array.isArray(item);
+  }
+
+  // Function to update all charts on theme change
+  window.updateChartsForTheme = function (chartInstances) {
+    if (!Array.isArray(chartInstances)) {
+      chartInstances = [chartInstances];
+    }
+
+    const colors = window.getChartColors();
+
+    chartInstances.forEach((chart) => {
+      if (!chart) return;
+
+      // Update grid colors
+      if (chart.options.scales) {
+        Object.keys(chart.options.scales).forEach((axis) => {
+          if (chart.options.scales[axis].grid) {
+            chart.options.scales[axis].grid.color = colors.grid;
+            chart.options.scales[axis].grid.borderColor = colors.gridMajor;
+          }
+          if (chart.options.scales[axis].ticks) {
+            chart.options.scales[axis].ticks.color = colors.text;
+          }
+          if (chart.options.scales[axis].title) {
+            chart.options.scales[axis].title.color = colors.textPrimary;
+          }
+        });
+      }
+
+      // Update legend colors
+      if (chart.options.plugins && chart.options.plugins.legend) {
+        if (chart.options.plugins.legend.labels) {
+          chart.options.plugins.legend.labels.color = colors.text;
+        }
+      }
+
+      // Update tooltip colors
+      if (chart.options.plugins && chart.options.plugins.tooltip) {
+        chart.options.plugins.tooltip.backgroundColor =
+          getEffectiveTheme() === "dark" ? "#3a3a3a" : "#ffffff";
+        chart.options.plugins.tooltip.titleColor = colors.textPrimary;
+        chart.options.plugins.tooltip.bodyColor = colors.text;
+        chart.options.plugins.tooltip.borderColor = colors.grid;
+      }
+
+      // Update the chart
+      chart.update();
+    });
+  };
+})();

src/baby_monitor/static/dark-mode.css

@@ -0,0 +1,258 @@
+/* Dark Mode CSS Variables and Theming System
+ * Supports automatic detection via prefers-color-scheme and manual override via .dark-mode class
+ */
+
+:root {
+  /* ===== LIGHT MODE (Default) ===== */
+
+  /* Background colors */
+  --bg-primary: #f0f0f0;
+  --bg-secondary: #ffffff;
+  --bg-tertiary: #f8f9fa;
+  --bg-card: #ffffff;
+
+  /* Text colors */
+  --text-primary: #333333;
+  --text-secondary: #666666;
+  --text-muted: #999999;
+  --text-inverse: #ffffff;
+
+  /* Border colors */
+  --border-color: #dddddd;
+  --border-light: #e0e0e0;
+  --border-lighter: #eeeeee;
+
+  /* Gradients - Brand */
+  --gradient-purple: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+  --gradient-blue: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+  --gradient-pink: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
+  --gradient-green: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
+  --gradient-orange: linear-gradient(135deg, #f2994a 0%, #f2c94c 100%);
+
+  /* Action colors */
+  --color-success: #4caf50;
+  --color-error: #dc3545;
+  --color-warning: #ff9800;
+  --color-info: #2196f3;
+  --color-danger: #f44336;
+
+  /* Action gradients */
+  --gradient-success: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
+  --gradient-error: linear-gradient(135deg, #dc3545 0%, #c62828 100%);
+  --gradient-danger: linear-gradient(135deg, #f44336 0%, #d32f2f 100%);
+
+  /* Interactive elements */
+  --input-bg: #ffffff;
+  --input-border: #dddddd;
+  --input-focus-border: #667eea;
+  --input-text: #333333;
+  --input-placeholder: #999999;
+
+  /* Shadows */
+  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
+  --shadow-md: 0 2px 10px rgba(0, 0, 0, 0.1);
+  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
+  --shadow-hover: 0 5px 15px rgba(0, 0, 0, 0.2);
+
+  /* Modal/Overlay */
+  --overlay-bg: rgba(0, 0, 0, 0.5);
+
+  /* Chart colors (vibrant for light backgrounds) */
+  --chart-grid: rgba(0, 0, 0, 0.1);
+  --chart-text: #666666;
+  --chart-color-1: #667eea;
+  --chart-color-2: #4facfe;
+  --chart-color-3: #f093fb;
+  --chart-color-4: #56ab2f;
+  --chart-color-5: #f2994a;
+  --chart-color-6: #764ba2;
+  --chart-color-7: #00f2fe;
+  --chart-color-8: #f5576c;
+}
+
+/* ===== DARK MODE ===== */
+/* Applied via @media query (auto-detect) OR .dark-mode class (manual override) */
+
+@media (prefers-color-scheme: dark) {
+  :root:not(.light-mode) {
+    /* Background colors - Dark theme */
+    --bg-primary: #1a1a1a;
+    --bg-secondary: #2d2d2d;
+    --bg-tertiary: #3a3a3a;
+    --bg-card: #2d2d2d;
+
+    /* Text colors - Light on dark */
+    --text-primary: #e0e0e0;
+    --text-secondary: #b0b0b0;
+    --text-muted: #808080;
+    --text-inverse: #1a1a1a;
+
+    /* Border colors - Lighter for visibility */
+    --border-color: #444444;
+    --border-light: #4a4a4a;
+    --border-lighter: #505050;
+
+    /* Gradients - Dimmed (~50% brightness reduction) */
+    --gradient-purple: linear-gradient(135deg, #3d4d8c 0%, #452d61 100%);
+    --gradient-blue: linear-gradient(135deg, #2f667f 0%, #00919a 100%);
+    --gradient-pink: linear-gradient(135deg, #905997 0%, #924344 100%);
+    --gradient-green: linear-gradient(135deg, #33661c 0%, #64873c 100%);
+    --gradient-orange: linear-gradient(135deg, #915b2d 0%, #917a2e 100%);
+
+    /* Action colors - Slightly brighter for visibility */
+    --color-success: #66bb6a;
+    --color-error: #ef5350;
+    --color-warning: #ffa726;
+    --color-info: #42a5f5;
+    --color-danger: #ff5252;
+
+    /* Action gradients - Dimmed */
+    --gradient-success: linear-gradient(135deg, #33661c 0%, #64873c 100%);
+    --gradient-error: linear-gradient(135deg, #a32a2a 0%, #8b2020 100%);
+    --gradient-danger: linear-gradient(135deg, #a32929 0%, #8b1e1e 100%);
+
+    /* Interactive elements */
+    --input-bg: #2d2d2d;
+    --input-border: #444444;
+    --input-focus-border: #667eea;
+    --input-text: #e0e0e0;
+    --input-placeholder: #808080;
+
+    /* Shadows - Lighter/softer for dark mode */
+    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
+    --shadow-md: 0 2px 10px rgba(0, 0, 0, 0.4);
+    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.5);
+    --shadow-hover: 0 5px 15px rgba(0, 0, 0, 0.6);
+
+    /* Modal/Overlay - Same opacity */
+    --overlay-bg: rgba(0, 0, 0, 0.5);
+
+    /* Chart colors - Brighter and more saturated for dark backgrounds */
+    --chart-grid: rgba(255, 255, 255, 0.1);
+    --chart-text: #b0b0b0;
+    --chart-color-1: #8b9eff;
+    --chart-color-2: #6ec5ff;
+    --chart-color-3: #ffb3ff;
+    --chart-color-4: #81c784;
+    --chart-color-5: #ffb74d;
+    --chart-color-6: #9c6bb8;
+    --chart-color-7: #4dffff;
+    --chart-color-8: #ff8a9b;
+  }
+}
+
+/* Manual override with .dark-mode class */
+body.dark-mode {
+  /* Background colors - Dark theme */
+  --bg-primary: #1a1a1a;
+  --bg-secondary: #2d2d2d;
+  --bg-tertiary: #3a3a3a;
+  --bg-card: #2d2d2d;
+
+  /* Text colors - Light on dark */
+  --text-primary: #e0e0e0;
+  --text-secondary: #b0b0b0;
+  --text-muted: #808080;
+  --text-inverse: #1a1a1a;
+
+  /* Border colors - Lighter for visibility */
+  --border-color: #444444;
+  --border-light: #4a4a4a;
+  --border-lighter: #505050;
+
+  /* Gradients - Dimmed (~50% brightness reduction) */
+  --gradient-purple: linear-gradient(135deg, #3d4d8c 0%, #452d61 100%);
+  --gradient-blue: linear-gradient(135deg, #2f667f 0%, #00919a 100%);
+  --gradient-pink: linear-gradient(135deg, #905997 0%, #924344 100%);
+  --gradient-green: linear-gradient(135deg, #33661c 0%, #64873c 100%);
+  --gradient-orange: linear-gradient(135deg, #915b2d 0%, #917a2e 100%);
+
+  /* Action colors - Slightly brighter for visibility */
+  --color-success: #66bb6a;
+  --color-error: #ef5350;
+  --color-warning: #ffa726;
+  --color-info: #42a5f5;
+  --color-danger: #ff5252;
+
+  /* Action gradients - Dimmed */
+  --gradient-success: linear-gradient(135deg, #33661c 0%, #64873c 100%);
+  --gradient-error: linear-gradient(135deg, #a32a2a 0%, #8b2020 100%);
+  --gradient-danger: linear-gradient(135deg, #a32929 0%, #8b1e1e 100%);
+
+  /* Interactive elements */
+  --input-bg: #2d2d2d;
+  --input-border: #444444;
+  --input-focus-border: #667eea;
+  --input-text: #e0e0e0;
+  --input-placeholder: #808080;
+
+  /* Shadows - Lighter/softer for dark mode */
+  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
+  --shadow-md: 0 2px 10px rgba(0, 0, 0, 0.4);
+  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.5);
+  --shadow-hover: 0 5px 15px rgba(0, 0, 0, 0.6);
+
+  /* Modal/Overlay - Same opacity */
+  --overlay-bg: rgba(0, 0, 0, 0.5);
+
+  /* Chart colors - Brighter and more saturated for dark backgrounds */
+  --chart-grid: rgba(255, 255, 255, 0.1);
+  --chart-text: #b0b0b0;
+  --chart-color-1: #8b9eff;
+  --chart-color-2: #6ec5ff;
+  --chart-color-3: #ffb3ff;
+  --chart-color-4: #81c784;
+  --chart-color-5: #ffb74d;
+  --chart-color-6: #9c6bb8;
+  --chart-color-7: #4dffff;
+  --chart-color-8: #ff8a9b;
+}
+
+/* Manual override with .light-mode class (forces light even when browser prefers dark) */
+body.light-mode {
+  /* Force light mode values - same as root defaults */
+  --bg-primary: #f0f0f0;
+  --bg-secondary: #ffffff;
+  --bg-tertiary: #f8f9fa;
+  --bg-card: #ffffff;
+  --text-primary: #333333;
+  --text-secondary: #666666;
+  --text-muted: #999999;
+  --text-inverse: #ffffff;
+  --border-color: #dddddd;
+  --border-light: #e0e0e0;
+  --border-lighter: #eeeeee;
+  --gradient-purple: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+  --gradient-blue: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+  --gradient-pink: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
+  --gradient-green: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
+  --gradient-orange: linear-gradient(135deg, #f2994a 0%, #f2c94c 100%);
+  --color-success: #4caf50;
+  --color-error: #dc3545;
+  --color-warning: #ff9800;
+  --color-info: #2196f3;
+  --color-danger: #f44336;
+  --gradient-success: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
+  --gradient-error: linear-gradient(135deg, #dc3545 0%, #c62828 100%);
+  --gradient-danger: linear-gradient(135deg, #f44336 0%, #d32f2f 100%);
+  --input-bg: #ffffff;
+  --input-border: #dddddd;
+  --input-focus-border: #667eea;
+  --input-text: #333333;
+  --input-placeholder: #999999;
+  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
+  --shadow-md: 0 2px 10px rgba(0, 0, 0, 0.1);
+  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
+  --shadow-hover: 0 5px 15px rgba(0, 0, 0, 0.2);
+  --overlay-bg: rgba(0, 0, 0, 0.5);
+  --chart-grid: rgba(0, 0, 0, 0.1);
+  --chart-text: #666666;
+  --chart-color-1: #667eea;
+  --chart-color-2: #4facfe;
+  --chart-color-3: #f093fb;
+  --chart-color-4: #56ab2f;
+  --chart-color-5: #f2994a;
+  --chart-color-6: #764ba2;
+  --chart-color-7: #00f2fe;
+  --chart-color-8: #f5576c;
+}

src/baby_monitor/static/diapers.html

@@ -4,6 +4,9 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Diapers - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
+    <script src="/chart-theme.js"></script>
     <link rel="stylesheet" href="/menu.css" />
     <style>
       * {
@@ -16,7 +19,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
         min-height: 100vh;
         max-width: 800px;
         margin: 2rem auto;
@@ -24,26 +27,27 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
         box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
         padding: 40px;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
 
       .button {
-        background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
+        background: var(--gradient-pink);
+        background-color: #f093fb;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -79,13 +83,13 @@
       .loading {
         text-align: center;
         padding: 40px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state {
         text-align: center;
         padding: 60px 20px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state-icon {
@@ -94,7 +98,7 @@
       }
 
       .empty-state h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
       }
 
@@ -105,12 +109,12 @@
       .chart-container {
         margin-bottom: 40px;
         padding: 20px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
       }
 
       .chart-container h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -150,29 +154,37 @@
 
       .controls label {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
       }
 
-      .controls select {
+      .controls select,
+      .controls input {
         padding: 8px 16px;
-        border: 1px solid #ddd;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         cursor: pointer;
-        background: white;
+        background: var(--bg-secondary);
+        color: var(--text-primary);
       }
 
-      .controls select:focus {
+      .controls select:focus,
+      .controls input:focus {
         outline: none;
         border-color: #f093fb;
       }
 
+      .controls input[readonly] {
+        opacity: 0.6;
+        cursor: default;
+      }
+
       .diapers-list {
         margin-top: 40px;
       }
 
       .diapers-list h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -180,9 +192,9 @@
       .diapers-scroll {
         max-height: 500px;
         overflow-y: auto;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 8px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
       }
 
       .diaper-item {
@@ -190,13 +202,13 @@
         justify-content: space-between;
         align-items: center;
         padding: 15px 20px;
-        background: white;
-        border-bottom: 1px solid #eee;
+        background: var(--bg-secondary);
+        border-bottom: 1px solid var(--border-lighter);
         transition: background 0.2s;
       }
 
       .diaper-item:hover {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
       }
 
       .diaper-item:last-child {
@@ -209,13 +221,13 @@
 
       .diaper-time {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 5px;
       }
 
       .diaper-details {
         font-size: 14px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .diaper-badge {
@@ -280,7 +292,10 @@
       let allChildren = [];
       let currentDaysRange =
         parseInt(localStorage.getItem("lastDiaperTimeRange")) || 7;
-      let selectedChildId = null; // null means "All Children"
+      let selectedChildId = null; // null means show first/only child
+      let barChartInstance = null; // Track chart instance for proper cleanup
+      let poopPieChartInstance = null;
+      let peePieChartInstance = null;
 
       // Restore last selected child from localStorage
       const lastChildId = localStorage.getItem("lastDiaperChildFilter");
@@ -321,6 +336,11 @@
 
           if (response.ok) {
             allChildren = await response.json();
+
+            // Auto-select first child if no selection exists
+            if (selectedChildId === null && allChildren.length > 0) {
+              selectedChildId = allChildren[0].id;
+            }
           }
         } catch (error) {
           console.error("Error loading children:", error);
@@ -334,8 +354,7 @@
       }
 
       function onChildChange(event) {
-        selectedChildId =
-          event.target.value === "all" ? null : parseInt(event.target.value);
+        selectedChildId = parseInt(event.target.value);
         localStorage.setItem("lastDiaperChildFilter", event.target.value);
         displayDiaperChanges(allDiaperChanges);
       }
@@ -349,6 +368,7 @@
               <div class="empty-state-icon">🧷</div>
               <h2>No Diaper Changes Yet</h2>
               <p>Start tracking diaper changes from the home page</p>
+              <button class="button" onclick="window.location.href='/'">Go Home</button>
             </div>
           `;
         } else {
@@ -367,11 +387,24 @@
 
           content.innerHTML = `
             <div class="controls">
-              <label for="childFilter">Child:</label>
-              <select id="childFilter" onchange="onChildChange(event)">
-                <option value="all" ${selectedChildId === null ? "selected" : ""}>All Children</option>
-                ${childOptions}
-              </select>
+              ${
+                allChildren.length === 1
+                  ? `
+                <label for="childDisplay">Child:</label>
+                <input
+                  type="text"
+                  id="childDisplay"
+                  value="${allChildren[0].name}"
+                  readonly
+                />
+              `
+                  : `
+                <label for="childFilter">Child:</label>
+                <select id="childFilter" onchange="onChildChange(event)">
+                  ${childOptions}
+                </select>
+              `
+              }
 
               <label for="daysRange">Time Range:</label>
               <select id="daysRange" onchange="onDaysRangeChange(event)">
@@ -764,7 +797,12 @@
       function renderBarChart(chartData) {
         const ctx = document.getElementById("diaperChart").getContext("2d");
 
-        new Chart(ctx, {
+        // Destroy existing chart instance if it exists
+        if (barChartInstance) {
+          barChartInstance.destroy();
+        }
+
+        barChartInstance = new Chart(ctx, {
           type: "bar",
           data: {
             labels: chartData.labels,
@@ -819,7 +857,7 @@
               },
             },
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 title: {
                   display: true,
@@ -835,10 +873,7 @@
                     size: 12,
                   },
                 },
-                grid: {
-                  color: "rgba(0, 0, 0, 0.05)",
-                },
-              },
+              }),
               x: {
                 ticks: {
                   font: {
@@ -857,6 +892,11 @@
       function renderPoopPieChart(chartData) {
         const ctx = document.getElementById("poopPieChart").getContext("2d");
 
+        // Destroy existing chart instance if it exists
+        if (poopPieChartInstance) {
+          poopPieChartInstance.destroy();
+        }
+
         const colors = {
           Light: {
             bg: "rgba(139, 69, 19, 0.5)",
@@ -883,7 +923,7 @@
           (label) => colors[label]?.border || "rgba(200, 200, 200, 1)",
         );
 
-        new Chart(ctx, {
+        poopPieChartInstance = new Chart(ctx, {
           type: "pie",
           data: {
             labels: chartData.labels,
@@ -939,6 +979,11 @@
       function renderPeePieChart(chartData) {
         const ctx = document.getElementById("peePieChart").getContext("2d");
 
+        // Destroy existing chart instance if it exists
+        if (peePieChartInstance) {
+          peePieChartInstance.destroy();
+        }
+
         const colors = {
           Light: {
             bg: "rgba(255, 215, 0, 0.5)",
@@ -965,7 +1010,7 @@
           (label) => colors[label]?.border || "rgba(200, 200, 200, 1)",
         );
 
-        new Chart(ctx, {
+        peePieChartInstance = new Chart(ctx, {
           type: "pie",
           data: {
             labels: chartData.labels,
@@ -1051,6 +1096,16 @@
 
       // Load data on page load
       loadDiaperChanges();
+
+      // Listen for theme changes and update charts
+      window.addEventListener("themechange", () => {
+        const charts = [
+          barChartInstance,
+          poopPieChartInstance,
+          peePieChartInstance,
+        ].filter((c) => c);
+        updateChartsForTheme(charts);
+      });
     </script>
   </body>
 </html>

src/baby_monitor/static/feedings.html

@@ -4,6 +4,9 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Feedings - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
+    <script src="/chart-theme.js"></script>
     <link rel="stylesheet" href="/menu.css" />
     <style>
       * {
@@ -16,7 +19,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
         min-height: 100vh;
         max-width: 800px;
         margin: 2rem auto;
@@ -24,26 +27,27 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
         box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
         padding: 40px;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
 
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -79,13 +83,13 @@
       .loading {
         text-align: center;
         padding: 40px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state {
         text-align: center;
         padding: 60px 20px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state-icon {
@@ -94,7 +98,7 @@
       }
 
       .empty-state h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
       }
 
@@ -105,12 +109,12 @@
       .chart-container {
         margin-bottom: 40px;
         padding: 20px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
       }
 
       .chart-container h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -148,14 +152,14 @@
       }
 
       .stat-card {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         padding: 20px;
         border-radius: 8px;
         text-align: center;
       }
 
       .stat-card h3 {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 14px;
         font-weight: 600;
         text-transform: uppercase;
@@ -163,7 +167,7 @@
       }
 
       .stat-card .stat-value {
-        color: #333;
+        color: var(--text-primary);
         font-size: 32px;
         font-weight: 700;
       }
@@ -182,21 +186,34 @@
 
       .controls label {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
       }
 
-      .controls select {
+      .controls select,
+      .controls input {
         padding: 8px 16px;
-        border: 1px solid #ddd;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         cursor: pointer;
-        background: white;
+        background: var(--bg-secondary);
+        color: var(--text-primary);
+      }
+
+      .controls select:focus,
+      .controls input:focus {
+        outline: none;
+        border-color: var(--input-focus-border);
+      }
+
+      .controls input[readonly] {
+        opacity: 0.6;
+        cursor: default;
       }
 
       .controls select:focus {
         outline: none;
-        border-color: #667eea;
+        border-color: var(--input-focus-border);
       }
 
       .feedings-list {
@@ -204,7 +221,7 @@
       }
 
       .feedings-list h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -212,9 +229,9 @@
       .feedings-scroll {
         max-height: 500px;
         overflow-y: auto;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 8px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
       }
 
       .feeding-item {
@@ -222,13 +239,13 @@
         justify-content: space-between;
         align-items: center;
         padding: 15px 20px;
-        background: white;
-        border-bottom: 1px solid #eee;
+        background: var(--bg-secondary);
+        border-bottom: 1px solid var(--border-lighter);
         transition: background 0.2s;
       }
 
       .feeding-item:hover {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
       }
 
       .feeding-item:last-child {
@@ -241,13 +258,13 @@
 
       .feeding-time {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 5px;
       }
 
       .feeding-details {
         font-size: 14px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .feeding-type-badge {
@@ -317,8 +334,10 @@
       let allChildren = [];
       let currentDaysRange =
         parseInt(localStorage.getItem("lastFeedingTimeRange")) || 7;
-      let selectedChildId = null; // null means "All Children"
+      let selectedChildId = null; // null means show first/only child
       let barChartInstance = null;
+      let pieChartInstance = null;
+      let durationChartInstance = null;
 
       // Restore last selected child from localStorage
       const lastChildId = localStorage.getItem("lastFeedingChildFilter");
@@ -359,6 +378,11 @@
 
           if (response.ok) {
             allChildren = await response.json();
+
+            // Auto-select first child if no selection exists
+            if (selectedChildId === null && allChildren.length > 0) {
+              selectedChildId = allChildren[0].id;
+            }
           }
         } catch (error) {
           console.error("Error loading children:", error);
@@ -372,8 +396,7 @@
       }
 
       function onChildChange(event) {
-        selectedChildId =
-          event.target.value === "all" ? null : parseInt(event.target.value);
+        selectedChildId = parseInt(event.target.value);
         localStorage.setItem("lastFeedingChildFilter", event.target.value);
         displayFeedings(allFeedings);
       }
@@ -381,35 +404,52 @@
       function displayFeedings(feedings) {
         const content = document.getElementById("content");
 
-        if (feedings.length === 0) {
+        // Check if we have children data
+        if (allChildren.length === 0) {
           content.innerHTML = `
             <div class="empty-state">
-              <div class="empty-state-icon">🍼</div>
-              <h2>No Feedings Yet</h2>
-              <p>Start tracking feeding sessions from the home page</p>
+              <div class="empty-state-icon">👶</div>
+              <h2>No Children Added</h2>
+              <p>Please add a child first before tracking feedings</p>
+              <button class="button" onclick="window.location.href='/add-child.html'">Add Child</button>
             </div>
           `;
-        } else {
-          // Prepare chart data
-          const barChartData = prepareBarChartData(feedings);
-          const pieChartData = preparePieChartData(feedings);
-          const durationChartData = prepareDurationChartData(feedings);
+          return;
+        }
 
-          // Build child dropdown options
-          const childOptions = allChildren
-            .map(
-              (child) =>
-                `<option value="${child.id}" ${selectedChildId === child.id ? "selected" : ""}>${child.name}</option>`,
-            )
-            .join("");
+        // Prepare chart data (works with empty arrays too)
+        const barChartData = prepareBarChartData(feedings);
+        const pieChartData = preparePieChartData(feedings);
+        const durationChartData = prepareDurationChartData(feedings);
 
-          content.innerHTML = `
+        // Build child dropdown options
+        const childOptions = allChildren
+          .map(
+            (child) =>
+              `<option value="${child.id}" ${selectedChildId === child.id ? "selected" : ""}>${child.name}</option>`,
+          )
+          .join("");
+
+        content.innerHTML = `
             <div class="controls">
-              <label for="childFilter">Child:</label>
-              <select id="childFilter" onchange="onChildChange(event)">
-                <option value="all" ${selectedChildId === null ? "selected" : ""}>All Children</option>
-                ${childOptions}
-              </select>
+              ${
+                allChildren.length === 1
+                  ? `
+                <label for="childDisplay">Child:</label>
+                <input
+                  type="text"
+                  id="childDisplay"
+                  value="${allChildren[0].name}"
+                  readonly
+                />
+              `
+                  : `
+                <label for="childFilter">Child:</label>
+                <select id="childFilter" onchange="onChildChange(event)">
+                  ${childOptions}
+                </select>
+              `
+              }
 
               <label for="daysRange">Time Range:</label>
               <select id="daysRange" onchange="onDaysRangeChange(event)">
@@ -446,14 +486,13 @@
             </div>
           `;
 
-          // Render charts
-          renderBarChart(barChartData);
-          renderPieChart(pieChartData);
-          renderDurationChart(durationChartData);
+        // Render charts
+        renderBarChart(barChartData);
+        renderPieChart(pieChartData);
+        renderDurationChart(durationChartData);
 
-          // Render feeding list
-          renderFeedingList(feedings);
-        }
+        // Render feeding list
+        renderFeedingList(feedings);
       }
 
       function renderFeedingList(feedings) {
@@ -901,7 +940,7 @@
                   display: false,
                 },
               },
-              y: {
+              y: getChartScaleOptions("y", {
                 stacked: true,
                 beginAtZero: true,
                 title: {
@@ -920,10 +959,7 @@
                     return Math.round(value) + "m";
                   },
                 },
-                grid: {
-                  color: "rgba(0, 0, 0, 0.05)",
-                },
-              },
+              }),
             },
             plugins: {
               legend: {
@@ -961,6 +997,11 @@
       function renderPieChart(chartData) {
         const ctx = document.getElementById("pieChart").getContext("2d");
 
+        // Destroy existing chart instance if it exists
+        if (pieChartInstance) {
+          pieChartInstance.destroy();
+        }
+
         // Color mapping for each type
         const colorMap = {
           "Left Breast": {
@@ -985,7 +1026,7 @@
           (label) => colorMap[label]?.border || "rgba(200, 200, 200, 1)",
         );
 
-        new Chart(ctx, {
+        pieChartInstance = new Chart(ctx, {
           type: "pie",
           data: {
             labels: chartData.labels,
@@ -1041,7 +1082,12 @@
       function renderDurationChart(chartData) {
         const ctx = document.getElementById("durationChart").getContext("2d");
 
-        new Chart(ctx, {
+        // Destroy existing chart instance if it exists
+        if (durationChartInstance) {
+          durationChartInstance.destroy();
+        }
+
+        durationChartInstance = new Chart(ctx, {
           type: "bar",
           data: {
             labels: chartData.labels,
@@ -1081,7 +1127,7 @@
               },
             },
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 title: {
                   display: true,
@@ -1097,11 +1143,8 @@
                     size: 12,
                   },
                 },
-                grid: {
-                  color: "rgba(0, 0, 0, 0.05)",
-                },
-              },
-              x: {
+              }),
+              x: getChartScaleOptions("x", {
                 title: {
                   display: true,
                   text: "Duration (minutes)",
@@ -1118,7 +1161,7 @@
                 grid: {
                   display: false,
                 },
-              },
+              }),
             },
           },
         });
@@ -1157,6 +1200,16 @@
 
       // Load data on page load
       loadFeedings();
+
+      // Listen for theme changes and update charts
+      window.addEventListener("themechange", () => {
+        const charts = [
+          barChartInstance,
+          pieChartInstance,
+          durationChartInstance,
+        ].filter((c) => c);
+        updateChartsForTheme(charts);
+      });
     </script>
   </body>
 </html>

src/baby_monitor/static/index.html

@@ -4,27 +4,37 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
+    <script src="/chart-theme.js"></script>
     <link rel="stylesheet" href="/menu.css" />
     <style>
+      * {
+        margin: 0;
+        padding: 0;
+        box-sizing: border-box;
+      }
+
       body {
         font-family: Arial, sans-serif;
         max-width: 800px;
         margin: 2rem auto;
         padding: 0 1rem;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
+        overflow-x: hidden;
       }
       .container {
-        background: white;
+        background: var(--bg-secondary);
         padding: 2rem;
         border-radius: 8px;
-        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
+        box-shadow: var(--shadow-md);
       }
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 1rem;
       }
       .greeting {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 1.1rem;
         margin-bottom: 2rem;
       }
@@ -59,7 +69,9 @@
         padding: 2rem;
         font-size: 1.5rem;
         margin-bottom: 1.5rem;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
+        color: white;
         border-radius: 8px;
         transition:
           transform 0.2s,
@@ -68,13 +80,16 @@
       .feeding-button:hover {
         transform: translateY(-2px);
         box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
-        background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
       }
       .feeding-button.active {
         background: linear-gradient(135deg, #f44336 0%, #e91e63 100%);
+        background-color: #f44336;
       }
       .feeding-button.active:hover {
         background: linear-gradient(135deg, #e91e63 0%, #f44336 100%);
+        background-color: #e91e63;
       }
       .feeding-info {
         font-size: 0.9rem;
@@ -97,7 +112,7 @@
         display: flex;
       }
       .modal-content {
-        background: white;
+        background: var(--bg-secondary);
         padding: 2rem;
         border-radius: 8px;
         max-width: 400px;
@@ -107,7 +122,7 @@
       .modal h2 {
         margin-top: 0;
         margin-bottom: 1.5rem;
-        color: #333;
+        color: var(--text-primary);
       }
       .form-group {
         margin-bottom: 1rem;
@@ -115,13 +130,13 @@
       .form-group label {
         display: block;
         margin-bottom: 0.5rem;
-        color: #333;
+        color: var(--text-primary);
         font-weight: 600;
       }
       .form-group select {
         width: 100%;
         padding: 0.75rem;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 4px;
         font-size: 1rem;
       }
@@ -145,7 +160,9 @@
         padding: 2rem;
         font-size: 1.5rem;
         margin-bottom: 1.5rem;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
+        color: white;
         border-radius: 8px;
         transition:
           transform 0.2s,
@@ -153,20 +170,69 @@
       }
       .sleep-button:hover {
         transform: translateY(-2px);
-        box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
-        background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
+        box-shadow: 0 6px 20px rgba(79, 172, 254, 0.4);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
       }
       .sleep-button.active {
-        background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
       }
       .sleep-button.active:hover {
-        background: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
       }
       .sleep-info {
         font-size: 0.9rem;
         margin-top: 0.5rem;
         opacity: 0.9;
       }
+      .recent-activity {
+        margin-top: 2rem;
+        padding: 1.5rem;
+        background: var(--bg-tertiary);
+        border-radius: 8px;
+      }
+      .recent-activity h3 {
+        margin-top: 0;
+        margin-bottom: 1rem;
+        color: var(--text-primary);
+        font-size: 1.1rem;
+      }
+      .activity-grid {
+        display: flex;
+        flex-direction: column;
+        gap: 1rem;
+      }
+      .activity-card {
+        background: var(--bg-secondary);
+        padding: 1rem;
+        border-radius: 6px;
+        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+      }
+      .activity-card .icon {
+        font-size: 1.5rem;
+        margin-bottom: 0.5rem;
+      }
+      .activity-card .type {
+        font-weight: 600;
+        color: var(--text-primary);
+        margin-bottom: 0.25rem;
+      }
+      .activity-card .time {
+        font-size: 0.85rem;
+        color: var(--text-secondary);
+      }
+      .activity-card .details {
+        font-size: 0.85rem;
+        color: #888;
+        margin-top: 0.5rem;
+      }
+      .activity-card.empty {
+        opacity: 0.5;
+        font-style: italic;
+        color: #999;
+      }
     </style>
   </head>
   <body>
@@ -240,6 +306,9 @@
       const token = localStorage.getItem("access_token");
       const username = localStorage.getItem("username");
 
+      // Initialize burger menu
+      initBurgerMenu({ includeHome: true });
+
       // Check if user is logged in
       if (!token) {
         window.location.href = "/login.html";
@@ -262,11 +331,6 @@
             }
           })
           .then((user) => {
-            // Initialize burger menu
-            initBurgerMenu({
-              includeHome: true,
-            });
-
             // Check if user has any children
             return fetch("/api/children", {
               headers: {
@@ -321,6 +385,7 @@
       let activeSleep = null;
       let lastSleep = null;
       let sleepUpdateTimerInterval = null;
+      let lastDiaperChange = null;
 
       async function loadFeedingStatus(children) {
         userChildren = children;
@@ -337,8 +402,8 @@
             activeFeeding = await activeResponse.json();
           }
 
-          // Fetch all feedings to get the last one
-          const feedingsResponse = await fetch("/api/feedings", {
+          // Fetch the 10 most recent feedings to calculate the most recent session
+          const feedingsResponse = await fetch("/api/feedings?limit=10", {
             headers: {
               Authorization: `Bearer ${token}`,
             },
@@ -347,8 +412,68 @@
           if (feedingsResponse.ok) {
             const feedings = await feedingsResponse.json();
             if (feedings.length > 0) {
-              // Feedings are ordered by start_time desc, so first is most recent
-              lastFeeding = feedings[0];
+              // Calculate the most recent feeding session
+              let sessionStart = feedings[0].start_time;
+              let sessionEnd = feedings[0].end_time || feedings[0].start_time;
+              let sessionChildId = feedings[0].child_id;
+              let sessionEntries = [feedings[0]];
+
+              for (let i = 1; i < feedings.length; i++) {
+                const entry = feedings[i];
+                // Only group entries for the same child (ignore feeding type)
+                if (entry.child_id !== sessionChildId) {
+                  break;
+                }
+                // If the gap between this entry's end_time and current sessionStart is more than 30 min, stop
+                const prevEnd = entry.end_time || entry.start_time;
+                const sessionStartDate = new Date(sessionStart);
+                const prevEndDate = new Date(prevEnd);
+                const diffMins = Math.abs(
+                  (sessionStartDate - prevEndDate) / 60000,
+                );
+                if (diffMins > 30) {
+                  break;
+                }
+                // Extend session to include this entry
+                sessionStart = entry.start_time;
+                sessionEntries.push(entry);
+              }
+
+              // Calculate accumulated feeding time for all events in the session
+              let accumulatedMinutes = 0;
+              sessionEntries.forEach((entry) => {
+                if (entry.end_time && entry.start_time) {
+                  const start = new Date(entry.start_time);
+                  const end = new Date(entry.end_time);
+                  const diffMs = end - start;
+                  if (diffMs > 0) {
+                    accumulatedMinutes += Math.floor(diffMs / 60000);
+                  }
+                }
+              });
+
+              // Build a string showing all feeding types used during the session
+              const feedingTypesSet = new Set();
+              sessionEntries.forEach((entry) => {
+                if (entry.feeding_type) {
+                  feedingTypesSet.add(entry.feeding_type);
+                }
+              });
+              const feedingTypesString = Array.from(feedingTypesSet)
+                .map(formatFeedingType)
+                .join(", ");
+
+              // Compose a session object
+              lastFeeding = {
+                child_id: sessionChildId,
+                feeding_type: feedings[0].feeding_type,
+                start_time: sessionStart,
+                end_time: sessionEnd,
+                entries: sessionEntries,
+                child_name: feedings[0].child_name,
+                accumulated_minutes: accumulatedMinutes,
+                feeding_types_string: feedingTypesString,
+              };
             }
           }
 
@@ -376,6 +501,20 @@
               lastSleep = sleeps[0];
             }
           }
+
+          // Fetch all diaper changes to get the last one
+          const diaperResponse = await fetch("/api/diaper-changes", {
+            headers: {
+              Authorization: `Bearer ${token}`,
+            },
+          });
+
+          if (diaperResponse.ok) {
+            const diapers = await diaperResponse.json();
+            if (diapers.length > 0) {
+              lastDiaperChange = diapers[0];
+            }
+          }
         } catch (error) {
           console.error("Error loading feeding status:", error);
         }
@@ -449,7 +588,7 @@
             </button>
           `
           : `
-            <button class="feeding-button" onclick="showStartFeedingModal()">
+            <button class="feeding-button" onclick="window.location.href='/log-feeding.html'">
               🍼 Started Feeding
             </button>
           `;
@@ -478,9 +617,100 @@
           </button>
           ${feedingButtonHtml}
           ${sleepButtonHtml}
+          ${buildRecentActivitySection()}
         `;
       }
 
+      function buildRecentActivitySection() {
+        // Build diaper card
+        const diaperCard = lastDiaperChange
+          ? `
+            <a href="/diapers.html" class="activity-card" style="text-decoration:none; color:inherit;">
+              <div class="icon">🧷</div>
+              <div class="type">Last Diaper</div>
+              <div class="time">${formatTime(lastDiaperChange.change_time)}</div>
+              <div class="details">
+                ${lastDiaperChange.poop_amount ? `💩 ${lastDiaperChange.poop_amount}` : ""}
+                ${lastDiaperChange.poop_amount && lastDiaperChange.pee_amount ? " • " : ""}
+                ${lastDiaperChange.pee_amount ? `💧 ${lastDiaperChange.pee_amount}` : ""}
+              </div>
+            </a>
+          `
+          : `
+            <a href="/diapers.html" class="activity-card empty" style="text-decoration:none; color:inherit;">
+              <div class="icon">🧷</div>
+              <div class="type">No diaper changes yet</div>
+            </a>
+          `;
+
+        // Build feeding card
+        const feedingCard = lastFeeding
+          ? `
+            <a href="/feedings.html" class="activity-card" style="text-decoration:none; color:inherit;">
+              <div class="icon">🍼</div>
+              <div class="type">Last Feeding Session</div>
+              <div class="time">${formatTime(lastFeeding.start_time)}</div>
+              <div class="details">
+                ${lastFeeding.feeding_types_string ? `${lastFeeding.feeding_types_string}` : ""}
+                ${lastFeeding.feeding_types_string && lastFeeding.accumulated_minutes ? " • " : ""}
+                ${lastFeeding.accumulated_minutes} minutes total
+                ${lastFeeding.end_time ? "" : " (ongoing)"}
+              </div>
+            </a>
+          `
+          : `
+            <a href="/feedings.html" class="activity-card empty" style="text-decoration:none; color:inherit;">
+              <div class="icon">🍼</div>
+              <div class="type">No feedings yet</div>
+            </a>
+          `;
+
+        // Build sleep card
+        const sleepCard = lastSleep
+          ? `
+            <a href="/sleep.html" class="activity-card" style="text-decoration:none; color:inherit;">
+              <div class="icon">😴</div>
+              <div class="type">Last Sleep</div>
+              <div class="time">${formatTime(lastSleep.start_time)}</div>
+              <div class="details">
+                Duration: ${lastSleep.end_time ? calculateDuration(lastSleep.start_time, lastSleep.end_time) : "ongoing"}
+              </div>
+            </a>
+          `
+          : `
+            <a href="/sleep.html" class="activity-card empty" style="text-decoration:none; color:inherit;">
+              <div class="icon">😴</div>
+              <div class="type">No sleep sessions yet</div>
+            </a>
+          `;
+
+        return `
+          <div class="recent-activity">
+            <h3>📊 Recent Activity</h3>
+            <div class="activity-grid">
+              ${diaperCard}
+              ${feedingCard}
+              ${sleepCard}
+            </div>
+          </div>
+        `;
+      }
+
+      function calculateDuration(startTime, endTime) {
+        const start = new Date(startTime);
+        const end = new Date(endTime);
+        const diffMs = end - start;
+        const diffMins = Math.floor(diffMs / 60000);
+
+        if (diffMins < 60) {
+          return `${diffMins} min`;
+        }
+
+        const hours = Math.floor(diffMins / 60);
+        const mins = diffMins % 60;
+        return `${hours}h ${mins}m`;
+      }
+
       function formatFeedingType(type) {
         const types = {
           left_breast: "Left Breast",
@@ -510,18 +740,40 @@
         const childSelect = document.getElementById("modalChildId");
         const typeSelect = document.getElementById("modalFeedingType");
 
-        // Clear and populate child select
-        childSelect.innerHTML = '<option value="">Select a child</option>';
-        userChildren.forEach((child) => {
-          const option = document.createElement("option");
-          option.value = child.id;
-          option.textContent = child.name;
-          childSelect.appendChild(option);
-        });
+        // Clear and populate child select or show single child
+        if (userChildren.length === 1) {
+          // Single child: replace dropdown with text display
+          const child = userChildren[0];
+          const formGroup = childSelect.parentElement;
+          formGroup.innerHTML = `
+            <label for="modalChildName">Child</label>
+            <input
+              type="text"
+              id="modalChildName"
+              value="${child.name}"
+              readonly
+              style="background-color: #f5f5f5; cursor: default;"
+            />
+            <input type="hidden" id="modalChildId" value="${child.id}" />
+          `;
+        } else {
+          // Multiple children: show dropdown
+          childSelect.innerHTML = '<option value="">Select a child</option>';
+          userChildren.forEach((child) => {
+            const option = document.createElement("option");
+            option.value = child.id;
+            option.textContent = child.name;
+            childSelect.appendChild(option);
+          });
 
-        // Set defaults based on last feeding
+          // Set defaults based on last feeding
+          if (lastFeeding) {
+            childSelect.value = lastFeeding.child_id;
+          }
+        }
+
+        // Set default feeding type based on last feeding
         if (lastFeeding) {
-          childSelect.value = lastFeeding.child_id;
           typeSelect.value = lastFeeding.feeding_type;
         }
 
@@ -630,24 +882,7 @@
       }
 
       function showStartSleepModal() {
-        const modal = document.getElementById("startSleepModal");
-        const childSelect = document.getElementById("modalSleepChildId");
-
-        // Clear and populate child select
-        childSelect.innerHTML = '<option value="">Select a child</option>';
-        userChildren.forEach((child) => {
-          const option = document.createElement("option");
-          option.value = child.id;
-          option.textContent = child.name;
-          childSelect.appendChild(option);
-        });
-
-        // Set default based on last sleep
-        if (lastSleep) {
-          childSelect.value = lastSleep.child_id;
-        }
-
-        modal.classList.add("show");
+        window.location.href = "/log-sleep.html";
       }
 
       function closeStartSleepModal() {

src/baby_monitor/static/log-diaper.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Log Diaper Change - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       * {
         margin: 0;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background-color: var(--bg-primary);
         min-height: 100vh;
         display: flex;
         justify-content: center;
@@ -24,22 +26,22 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
-        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+        box-shadow: var(--shadow-md);
         padding: 40px;
         max-width: 500px;
         width: 100%;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
@@ -51,7 +53,7 @@
       label {
         display: block;
         margin-bottom: 8px;
-        color: #333;
+        color: var(--text-primary);
         font-weight: 600;
         font-size: 14px;
       }
@@ -60,20 +62,28 @@
       select {
         width: 100%;
         padding: 12px;
-        border: 1px solid #ddd;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         transition: border-color 0.2s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
       }
 
       input:focus,
       select:focus {
         outline: none;
-        border-color: #667eea;
+        border-color: #f093fb;
+      }
+
+      input[readonly] {
+        opacity: 0.6;
+        cursor: default;
       }
 
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-pink);
+        background-color: #f093fb;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -90,7 +100,7 @@
 
       .button:hover {
         transform: translateY(-2px);
-        box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
+        box-shadow: 0 4px 12px rgba(240, 147, 251, 0.4);
       }
 
       .button:active {
@@ -137,25 +147,25 @@
 
       .help-text {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
         margin-top: 4px;
       }
 
       .loading {
         text-align: center;
         padding: 20px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .section-title {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 13px;
         font-weight: 600;
         text-transform: uppercase;
         letter-spacing: 0.5px;
         margin: 25px 0 15px 0;
         padding-top: 15px;
-        border-top: 1px solid #eee;
+        border-top: 1px solid var(--border-lighter);
       }
 
       .section-title:first-of-type {
@@ -235,7 +245,7 @@
         <button
           type="button"
           class="button secondary"
-          onclick="window.location.href='/'"
+          onclick="window.location.href = getReturnUrl()"
         >
           Cancel
         </button>
@@ -249,6 +259,16 @@
         window.location.href = "/login.html";
       }
 
+      // Determine return URL based on referrer
+      function getReturnUrl() {
+        const referrer = document.referrer;
+        if (referrer.includes("/diapers.html")) {
+          return "/diapers.html";
+        }
+        // Default to home page
+        return "/";
+      }
+
       // Check if we're in edit mode
       const urlParams = new URLSearchParams(window.location.search);
       const diaperChangeId = urlParams.get("id");
@@ -277,12 +297,31 @@
             children = await response.json();
             const select = document.getElementById("childSelect");
 
-            children.forEach((child) => {
-              const option = document.createElement("option");
-              option.value = child.id;
-              option.textContent = child.name;
-              select.appendChild(option);
-            });
+            // Populate select dropdown or show single child
+            if (children.length === 1) {
+              // Single child: replace dropdown with text display
+              const child = children[0];
+              const formGroup = select.parentElement;
+              formGroup.innerHTML = `
+                <label for="childName">Child *</label>
+                <input
+                  type="text"
+                  id="childName"
+                  value="${child.name}"
+                  readonly
+                />
+                <input type="hidden" id="childSelect" name="childSelect" value="${child.id}" />
+              `;
+            } else {
+              // Multiple children: show dropdown (clear the placeholder first)
+              select.innerHTML = "";
+              children.forEach((child) => {
+                const option = document.createElement("option");
+                option.value = child.id;
+                option.textContent = child.name;
+                select.appendChild(option);
+              });
+            }
 
             // If editing, load the diaper change data
             if (isEditMode) {
@@ -295,14 +334,39 @@
                 .toISOString()
                 .slice(0, 16);
 
-              // Load last used child from localStorage
-              const lastDiaperChange = JSON.parse(
-                localStorage.getItem("lastDiaperChange") || "{}",
-              );
+              // Load last used child from localStorage (only for multiple children)
+              if (children.length > 1) {
+                const lastDiaperChange = JSON.parse(
+                  localStorage.getItem("lastDiaperChange") || "{}",
+                );
 
-              if (lastDiaperChange.child_id) {
-                document.getElementById("childSelect").value =
-                  lastDiaperChange.child_id;
+                if (lastDiaperChange.child_id) {
+                  document.getElementById("childSelect").value =
+                    lastDiaperChange.child_id;
+                }
+              }
+
+              // Prepopulate poop and pee fields from most recent entry
+              try {
+                const response = await fetch("/api/diaper-changes", {
+                  headers: { Authorization: `Bearer ${token}` },
+                });
+                if (response.ok) {
+                  const changes = await response.json();
+                  if (changes.length > 0) {
+                    const last = changes[0];
+                    document.getElementById("poopAmount").value =
+                      last.poop_amount || "";
+                    document.getElementById("poopColor").value =
+                      last.poop_color || "";
+                    document.getElementById("peeAmount").value =
+                      last.pee_amount || "";
+                    document.getElementById("peeColor").value =
+                      last.pee_color || "";
+                  }
+                }
+              } catch (error) {
+                // Ignore error, just use default
               }
             }
           } else {
@@ -431,7 +495,7 @@
                 "success",
               );
               setTimeout(() => {
-                window.location.href = "/";
+                window.location.href = getReturnUrl();
               }, 1000);
             } else {
               const errorData = await response.json();

src/baby_monitor/static/log-feeding.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Log Feeding - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       * {
         margin: 0;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background-color: var(--bg-primary);
         min-height: 100vh;
         display: flex;
         justify-content: center;
@@ -24,22 +26,22 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
-        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+        box-shadow: var(--shadow-md);
         padding: 40px;
         max-width: 500px;
         width: 100%;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
@@ -51,7 +53,7 @@
       label {
         display: block;
         margin-bottom: 8px;
-        color: #333;
+        color: var(--text-primary);
         font-weight: 600;
         font-size: 14px;
       }
@@ -60,10 +62,12 @@
       select {
         width: 100%;
         padding: 12px;
-        border: 1px solid #ddd;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         transition: border-color 0.2s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
       }
 
       input:focus,
@@ -72,8 +76,14 @@
         border-color: #667eea;
       }
 
+      input[readonly] {
+        opacity: 0.6;
+        cursor: default;
+      }
+
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -137,14 +147,14 @@
 
       .help-text {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
         margin-top: 4px;
       }
 
       .loading {
         text-align: center;
         padding: 20px;
-        color: #666;
+        color: var(--text-secondary);
       }
     </style>
   </head>
@@ -206,6 +216,16 @@
         window.location.href = "/login.html";
       }
 
+      // Determine return URL based on referrer
+      function getReturnUrl() {
+        const referrer = document.referrer;
+        if (referrer.includes("/feedings.html")) {
+          return "/feedings.html";
+        }
+        // Default to home page
+        return "/";
+      }
+
       const form = document.getElementById("logFeedingForm");
       const messageDiv = document.getElementById("message");
       const submitBtn = document.getElementById("submitBtn");
@@ -259,13 +279,31 @@
               return;
             }
 
-            // Populate select dropdown
-            children.forEach((child) => {
-              const option = document.createElement("option");
-              option.value = child.id;
-              option.textContent = child.name;
-              childSelect.appendChild(option);
-            });
+            // Populate select dropdown or show single child
+            if (children.length === 1) {
+              // Single child: replace dropdown with text display
+              const child = children[0];
+              const formGroup = childSelect.parentElement;
+              formGroup.innerHTML = `
+                <label for="childName">Child</label>
+                <input
+                  type="text"
+                  id="childName"
+                  value="${child.name}"
+                  readonly
+                />
+                <input type="hidden" id="childId" name="childId" value="${child.id}" />
+              `;
+            } else {
+              // Multiple children: show dropdown (clear placeholder first)
+              childSelect.innerHTML = "";
+              children.forEach((child) => {
+                const option = document.createElement("option");
+                option.value = child.id;
+                option.textContent = child.name;
+                childSelect.appendChild(option);
+              });
+            }
 
             // Show form, hide loading
             loadingDiv.style.display = "none";
@@ -274,6 +312,22 @@
             // If editing, load the feeding data
             if (isEditMode) {
               loadFeedingData();
+            } else {
+              // Set default feeding type to most recent log entry
+              try {
+                const response = await fetch("/api/feedings", {
+                  headers: { Authorization: `Bearer ${token}` },
+                });
+                if (response.ok) {
+                  const feedings = await response.json();
+                  if (feedings.length > 0) {
+                    document.getElementById("feedingType").value =
+                      feedings[0].feeding_type;
+                  }
+                }
+              } catch (error) {
+                // Ignore error, just use default
+              }
             }
           } else {
             showMessage("Failed to load children", "error");
@@ -369,9 +423,9 @@
                 : "Feeding logged successfully!",
               "success",
             );
-            // Redirect to feedings page after 1 second
+            // Redirect to appropriate page after 1 second
             setTimeout(() => {
-              window.location.href = "/feedings.html";
+              window.location.href = getReturnUrl();
             }, 1000);
           } else {
             showMessage(
@@ -394,7 +448,7 @@
       }
 
       function goBack() {
-        window.location.href = "/";
+        window.location.href = getReturnUrl();
       }
     </script>
   </body>

src/baby_monitor/static/log-sleep.html

@@ -0,0 +1,423 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Log Sleep - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
+    <style>
+      * {
+        margin: 0;
+        padding: 0;
+        box-sizing: border-box;
+      }
+
+      body {
+        font-family:
+          -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
+          Cantarell, sans-serif;
+        background-color: var(--bg-primary);
+        min-height: 100vh;
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        padding: 20px;
+      }
+
+      .container {
+        background: var(--bg-secondary);
+        border-radius: 12px;
+        box-shadow: var(--shadow-md);
+        padding: 40px;
+        max-width: 500px;
+        width: 100%;
+      }
+
+      h1 {
+        color: var(--text-primary);
+        margin-bottom: 10px;
+        font-size: 28px;
+      }
+
+      .subtitle {
+        color: var(--text-secondary);
+        margin-bottom: 30px;
+        font-size: 14px;
+      }
+
+      .form-group {
+        margin-bottom: 20px;
+      }
+
+      label {
+        display: block;
+        margin-bottom: 8px;
+        color: var(--text-primary);
+        font-weight: 600;
+        font-size: 14px;
+      }
+
+      input,
+      select {
+        width: 100%;
+        padding: 12px;
+        border: 2px solid var(--border-color, #ddd);
+        border-radius: 6px;
+        font-size: 14px;
+        transition: border-color 0.2s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
+      }
+
+      input:focus,
+      select:focus {
+        outline: none;
+        border-color: #4facfe;
+      }
+
+      input[readonly] {
+        opacity: 0.6;
+        cursor: default;
+      }
+
+      .button {
+        background: var(--gradient-blue);
+        background-color: #4facfe;
+        color: white;
+        border: none;
+        padding: 12px 24px;
+        border-radius: 6px;
+        font-size: 16px;
+        font-weight: 600;
+        cursor: pointer;
+        transition:
+          transform 0.2s,
+          box-shadow 0.2s;
+        width: 100%;
+        margin-top: 10px;
+      }
+
+      .button:hover {
+        transform: translateY(-2px);
+        box-shadow: 0 4px 12px rgba(79, 172, 254, 0.4);
+      }
+
+      .button:active {
+        transform: translateY(0);
+      }
+
+      .button:disabled {
+        opacity: 0.6;
+        cursor: not-allowed;
+        transform: none;
+      }
+
+      .button.secondary {
+        background: #6c757d;
+        margin-top: 10px;
+      }
+
+      .button.secondary:hover {
+        box-shadow: 0 4px 12px rgba(108, 117, 125, 0.4);
+      }
+
+      .message {
+        padding: 12px;
+        border-radius: 6px;
+        margin-bottom: 20px;
+        display: none;
+      }
+
+      .message.show {
+        display: block;
+      }
+
+      .message.error {
+        background: #ffebee;
+        border-left: 4px solid #f44336;
+        color: #c62828;
+      }
+
+      .message.success {
+        background: #e8f5e9;
+        border-left: 4px solid #4caf50;
+        color: #2e7d32;
+      }
+
+      .help-text {
+        font-size: 12px;
+        color: var(--text-secondary);
+        margin-top: 4px;
+      }
+
+      .loading {
+        text-align: center;
+        padding: 20px;
+        color: var(--text-secondary);
+      }
+    </style>
+  </head>
+  <body>
+    <div class="container">
+      <h1>😴 Log Sleep</h1>
+      <p class="subtitle">Record a sleep session</p>
+
+      <div id="message" class="message"></div>
+
+      <div id="loadingChildren" class="loading">Loading children...</div>
+
+      <form id="logSleepForm" style="display: none">
+        <div class="form-group">
+          <label for="childId">Child *</label>
+          <select id="childId" name="childId" required>
+            <option value="">Select a child</option>
+          </select>
+        </div>
+
+        <div class="form-group">
+          <label for="startTime">Start Time *</label>
+          <input
+            type="datetime-local"
+            id="startTime"
+            name="startTime"
+            required
+          />
+          <p class="help-text">Defaults to current time</p>
+        </div>
+
+        <div class="form-group">
+          <label for="endTime">End Time</label>
+          <input type="datetime-local" id="endTime" name="endTime" />
+          <p class="help-text">Leave empty if sleep is ongoing</p>
+        </div>
+
+        <button type="submit" class="button" id="submitBtn">Log Sleep</button>
+        <button type="button" class="button secondary" onclick="goBack()">
+          Cancel
+        </button>
+      </form>
+    </div>
+
+    <script>
+      // Check if user is authenticated
+      const token = localStorage.getItem("access_token");
+      if (!token) {
+        window.location.href = "/login.html";
+      }
+
+      // Determine return URL based on referrer
+      function getReturnUrl() {
+        const referrer = document.referrer;
+        if (referrer.includes("/sleep.html")) {
+          return "/sleep.html";
+        }
+        // Default to home page
+        return "/";
+      }
+
+      const form = document.getElementById("logSleepForm");
+      const messageDiv = document.getElementById("message");
+      const submitBtn = document.getElementById("submitBtn");
+      const loadingDiv = document.getElementById("loadingChildren");
+      const childSelect = document.getElementById("childId");
+
+      // Check if we're editing an existing sleep session
+      const urlParams = new URLSearchParams(window.location.search);
+      const sleepId = urlParams.get("id");
+      const isEditMode = !!sleepId;
+
+      // Set default start time to now (only for new sleep sessions)
+      if (!isEditMode) {
+        const now = new Date();
+        const localDateTime = new Date(
+          now.getTime() - now.getTimezoneOffset() * 60000,
+        )
+          .toISOString()
+          .slice(0, 16);
+        document.getElementById("startTime").value = localDateTime;
+      }
+
+      // Update title and button text if editing
+      if (isEditMode) {
+        document.querySelector("h1").textContent = "😴 Edit Sleep";
+        document.querySelector(".subtitle").textContent =
+          "Update sleep session details";
+        submitBtn.textContent = "Update Sleep";
+      }
+
+      // Load user's children
+      async function loadChildren() {
+        try {
+          const response = await fetch("/api/children", {
+            headers: {
+              Authorization: `Bearer ${token}`,
+            },
+          });
+
+          if (response.ok) {
+            const children = await response.json();
+
+            if (children.length === 0) {
+              showMessage(
+                "No children found. Please add a child first.",
+                "error",
+              );
+              setTimeout(() => {
+                window.location.href = "/add-child.html";
+              }, 2000);
+              return;
+            }
+
+            // Populate select dropdown or show single child
+            if (children.length === 1) {
+              // Single child: replace dropdown with text display
+              const child = children[0];
+              const formGroup = childSelect.parentElement;
+              formGroup.innerHTML = `
+                <label for="childName">Child</label>
+                <input
+                  type="text"
+                  id="childName"
+                  value="${child.name}"
+                  readonly
+                />
+                <input type="hidden" id="childId" name="childId" value="${child.id}" />
+              `;
+            } else {
+              // Multiple children: show dropdown (clear placeholder first)
+              childSelect.innerHTML = "";
+              children.forEach((child) => {
+                const option = document.createElement("option");
+                option.value = child.id;
+                option.textContent = child.name;
+                childSelect.appendChild(option);
+              });
+            }
+
+            // Show form, hide loading
+            loadingDiv.style.display = "none";
+            form.style.display = "block";
+
+            // If editing, load the sleep data
+            if (isEditMode) {
+              loadSleepData();
+            }
+          } else {
+            showMessage("Failed to load children", "error");
+          }
+        } catch (error) {
+          showMessage("Network error loading children", "error");
+        }
+      }
+
+      async function loadSleepData() {
+        try {
+          const response = await fetch(`/api/sleep/${sleepId}`, {
+            headers: {
+              Authorization: `Bearer ${token}`,
+            },
+          });
+
+          if (response.ok) {
+            const sleep = await response.json();
+
+            // Populate form with existing data
+            document.getElementById("childId").value = sleep.child_id;
+
+            // Format datetime for datetime-local input
+            const startTime = new Date(sleep.start_time);
+            const startLocalDateTime = new Date(
+              startTime.getTime() - startTime.getTimezoneOffset() * 60000,
+            )
+              .toISOString()
+              .slice(0, 16);
+            document.getElementById("startTime").value = startLocalDateTime;
+
+            if (sleep.end_time) {
+              const endTime = new Date(sleep.end_time);
+              const endLocalDateTime = new Date(
+                endTime.getTime() - endTime.getTimezoneOffset() * 60000,
+              )
+                .toISOString()
+                .slice(0, 16);
+              document.getElementById("endTime").value = endLocalDateTime;
+            }
+          } else {
+            showMessage("Failed to load sleep data", "error");
+          }
+        } catch (error) {
+          showMessage("Network error loading sleep", "error");
+        }
+      }
+
+      loadChildren();
+
+      form.addEventListener("submit", async (e) => {
+        e.preventDefault();
+
+        const childId = parseInt(document.getElementById("childId").value);
+        const startTime = document.getElementById("startTime").value;
+        const endTimeValue = document.getElementById("endTime").value;
+
+        // Disable button during request
+        submitBtn.disabled = true;
+        submitBtn.textContent = isEditMode ? "Updating..." : "Logging...";
+        messageDiv.classList.remove("show");
+
+        try {
+          const url = isEditMode ? `/api/sleep/${sleepId}` : "/api/sleep";
+          const method = isEditMode ? "PUT" : "POST";
+
+          const response = await fetch(url, {
+            method: method,
+            headers: {
+              "Content-Type": "application/json",
+              Authorization: `Bearer ${token}`,
+            },
+            body: JSON.stringify({
+              child_id: childId,
+              start_time: startTime,
+              end_time: endTimeValue || null,
+            }),
+          });
+
+          const data = await response.json();
+
+          if (response.ok) {
+            showMessage(
+              isEditMode
+                ? "Sleep updated successfully!"
+                : "Sleep logged successfully!",
+              "success",
+            );
+            // Redirect to appropriate page after 1 second
+            setTimeout(() => {
+              window.location.href = getReturnUrl();
+            }, 1000);
+          } else {
+            showMessage(
+              data.detail ||
+                `Failed to ${isEditMode ? "update" : "log"} sleep. Please try again.`,
+              "error",
+            );
+          }
+        } catch (error) {
+          showMessage("Network error. Please try again.", "error");
+        } finally {
+          submitBtn.disabled = false;
+          submitBtn.textContent = isEditMode ? "Update Sleep" : "Log Sleep";
+        }
+      });
+
+      function showMessage(text, type) {
+        messageDiv.textContent = text;
+        messageDiv.className = `message ${type} show`;
+      }
+
+      function goBack() {
+        window.location.href = getReturnUrl();
+      }
+    </script>
+  </body>
+</html>

src/baby_monitor/static/login.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       body {
         font-family: Arial, sans-serif;
@@ -12,27 +14,33 @@
         align-items: center;
         height: 100vh;
         margin: 0;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
       }
       .login-container {
-        background: white;
+        background: var(--bg-secondary);
         padding: 2rem;
         border-radius: 8px;
-        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
+        box-shadow: var(--shadow-md);
         width: 300px;
       }
       h1 {
         text-align: center;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 1.5rem;
       }
       input {
         width: 100%;
         padding: 0.75rem;
         margin-bottom: 1rem;
-        border: 1px solid #ddd;
+        border: 1px solid var(--border-color);
         border-radius: 4px;
         box-sizing: border-box;
+        background-color: var(--input-bg);
+        color: var(--input-text);
+      }
+      input:focus {
+        outline: none;
+        border-color: var(--input-focus-border);
       }
       button {
         width: 100%;

src/baby_monitor/static/menu.css

@@ -5,18 +5,21 @@
   left: 1rem;
   cursor: pointer;
   z-index: 1000;
-  background: white;
+  background: var(--bg-secondary, #ffffff);
   padding: 0.5rem;
   border-radius: 4px;
-  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
+  box-shadow: var(--shadow-md, 0 2px 10px rgba(0, 0, 0, 0.1));
+  transition:
+    background 0.3s,
+    box-shadow 0.3s;
 }
 
 .burger-menu div {
   width: 25px;
   height: 3px;
-  background-color: #333;
+  background-color: var(--text-primary, #333333);
   margin: 5px 0;
-  transition: 0.3s;
+  transition: background-color 0.3s;
 }
 
 .menu-backdrop {
@@ -37,14 +40,17 @@
 .menu-overlay {
   position: fixed;
   top: 0;
-  left: -250px;
+  left: -100%;
   width: 250px;
   height: 100vh;
-  background: white;
-  box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
-  transition: left 0.3s;
+  background: var(--bg-secondary, #ffffff);
+  box-shadow: var(--shadow-md, 2px 0 10px rgba(0, 0, 0, 0.1));
+  transition:
+    left 0.3s,
+    background 0.3s;
   z-index: 999;
   padding: 4rem 1rem 1rem 1rem;
+  overflow: hidden;
 }
 
 .menu-overlay.open {
@@ -53,13 +59,17 @@
 
 .menu-item {
   padding: 1rem;
-  border-bottom: 1px solid #eee;
+  border-bottom: 1px solid var(--border-color, #eeeeee);
   cursor: pointer;
-  transition: background 0.2s;
+  transition:
+    background 0.2s,
+    color 0.3s,
+    border-color 0.3s;
+  color: var(--text-primary, #333333);
 }
 
 .menu-item:hover {
-  background: #f5f5f5;
+  background: var(--bg-tertiary, #f5f5f5);
 }
 
 .menu-item.admin {

src/baby_monitor/static/register.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Baby Monitor - Register</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <style>
       * {
         margin: 0;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: #667eea;
         min-height: 100vh;
         display: flex;
         justify-content: center;
@@ -33,14 +35,14 @@
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
         text-align: center;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
         text-align: center;
@@ -61,20 +63,23 @@
       input {
         width: 100%;
         padding: 12px;
-        border: 2px solid #e0e0e0;
+        border: 2px solid #ccc;
         border-radius: 6px;
         font-size: 16px;
         transition: border-color 0.3s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
       }
 
       input:focus {
         outline: none;
-        border-color: #667eea;
+        border-color: var(--input-focus-border);
       }
 
       .button {
         width: 100%;
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 14px;
@@ -173,7 +178,7 @@
 
       .password-requirements {
         font-size: 12px;
-        color: #666;
+        color: var(--text-secondary);
         margin-top: 5px;
       }
 
@@ -186,7 +191,7 @@
     <div class="container">
       <div id="loadingContainer" class="loading-container">
         <div class="spinner"></div>
-        <p style="color: #666">Validating invitation...</p>
+        <p style="color: var(--text-secondary)">Validating invitation...</p>
       </div>
 
       <div id="registerContainer" class="hidden">

src/baby_monitor/static/settings.html

@@ -4,6 +4,8 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Settings - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
     <link rel="stylesheet" href="/menu.css" />
     <style>
       * {
@@ -16,7 +18,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
         min-height: 100vh;
         max-width: 800px;
         margin: 2rem auto;
@@ -24,20 +26,20 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
         box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
         padding: 40px;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
@@ -45,12 +47,12 @@
       .section {
         margin-bottom: 40px;
         padding: 20px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
       }
 
       .section h2 {
-        color: #333;
+        color: var(--text-primary);
         font-size: 20px;
         margin-bottom: 20px;
         display: flex;
@@ -65,7 +67,7 @@
       .form-group label {
         display: block;
         margin-bottom: 8px;
-        color: #333;
+        color: var(--text-primary);
         font-weight: 600;
         font-size: 14px;
       }
@@ -73,24 +75,27 @@
       .form-group input {
         width: 100%;
         padding: 12px;
-        border: 2px solid #e0e0e0;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         transition: border-color 0.2s;
+        background-color: var(--input-bg);
+        color: var(--input-text);
       }
 
       .form-group input:focus {
         outline: none;
-        border-color: #667eea;
+        border-color: var(--input-focus-border);
       }
 
       .form-group input:disabled {
-        background-color: #f5f5f5;
+        opacity: 0.6;
         cursor: not-allowed;
       }
 
       .button {
-        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        background: var(--gradient-purple);
+        background-color: #667eea;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -125,7 +130,7 @@
       }
 
       .button.success {
-        background: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
+        background: var(--gradient-success);
       }
 
       .button.success:hover {
@@ -139,20 +144,20 @@
       }
 
       .child-card {
-        background: white;
+        background: var(--bg-secondary);
         padding: 20px;
         border-radius: 8px;
-        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+        box-shadow: var(--shadow-md);
       }
 
       .child-card h3 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 18px;
       }
 
       .child-info {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 14px;
         margin-bottom: 15px;
       }
@@ -169,7 +174,7 @@
       .loading {
         text-align: center;
         padding: 40px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .alert {
@@ -200,7 +205,7 @@
         width: 100%;
         padding: 15px;
         margin-bottom: 15px;
-        background: white;
+        background: var(--bg-secondary);
         border: 2px solid #667eea;
         color: #667eea;
         border-radius: 8px;
@@ -233,6 +238,140 @@
         </div>
       </div>
 
+      <div class="section">
+        <h2>🌓 Theme Preference</h2>
+        <p
+          style="
+            color: var(--text-secondary);
+            margin-bottom: 20px;
+            font-size: 14px;
+          "
+        >
+          Choose how Baby Monitor looks to you.
+        </p>
+        <div class="form-group">
+          <div style="display: flex; flex-direction: column; gap: 15px">
+            <label
+              style="
+                display: flex;
+                align-items: center;
+                cursor: pointer;
+                padding: 12px;
+                border: 2px solid var(--border-light);
+                border-radius: 8px;
+                transition: all 0.2s;
+              "
+              class="theme-option"
+              data-theme="light"
+            >
+              <input
+                type="radio"
+                name="theme"
+                value="light"
+                style="
+                  margin-right: 12px;
+                  width: 20px;
+                  height: 20px;
+                  cursor: pointer;
+                "
+              />
+              <div>
+                <div
+                  style="
+                    font-weight: 600;
+                    color: var(--text-primary);
+                    margin-bottom: 4px;
+                  "
+                >
+                  ☀️ Light Mode
+                </div>
+                <div style="font-size: 12px; color: var(--text-secondary)">
+                  Always use light theme
+                </div>
+              </div>
+            </label>
+            <label
+              style="
+                display: flex;
+                align-items: center;
+                cursor: pointer;
+                padding: 12px;
+                border: 2px solid var(--border-light);
+                border-radius: 8px;
+                transition: all 0.2s;
+              "
+              class="theme-option"
+              data-theme="dark"
+            >
+              <input
+                type="radio"
+                name="theme"
+                value="dark"
+                style="
+                  margin-right: 12px;
+                  width: 20px;
+                  height: 20px;
+                  cursor: pointer;
+                "
+              />
+              <div>
+                <div
+                  style="
+                    font-weight: 600;
+                    color: var(--text-primary);
+                    margin-bottom: 4px;
+                  "
+                >
+                  🌙 Dark Mode
+                </div>
+                <div style="font-size: 12px; color: var(--text-secondary)">
+                  Always use dark theme
+                </div>
+              </div>
+            </label>
+            <label
+              style="
+                display: flex;
+                align-items: center;
+                cursor: pointer;
+                padding: 12px;
+                border: 2px solid var(--border-light);
+                border-radius: 8px;
+                transition: all 0.2s;
+              "
+              class="theme-option"
+              data-theme="auto"
+            >
+              <input
+                type="radio"
+                name="theme"
+                value="auto"
+                style="
+                  margin-right: 12px;
+                  width: 20px;
+                  height: 20px;
+                  cursor: pointer;
+                "
+              />
+              <div>
+                <div
+                  style="
+                    font-weight: 600;
+                    color: var(--text-primary);
+                    margin-bottom: 4px;
+                  "
+                >
+                  🔄 Auto
+                </div>
+                <div style="font-size: 12px; color: var(--text-secondary)">
+                  Match your browser settings
+                </div>
+              </div>
+            </label>
+          </div>
+        </div>
+      </div>
+
       <div class="section">
         <h2>🔑 Change Password</h2>
         <form id="userForm">
@@ -261,12 +400,18 @@
           "
         >
           <h3 style="color: #dc3545; margin-bottom: 15px">⚠️ Danger Zone</h3>
-          <p style="color: #666; margin-bottom: 15px; font-size: 14px">
+          <p
+            style="
+              color: var(--text-secondary);
+              margin-bottom: 15px;
+              font-size: 14px;
+            "
+          >
             Deleting your account is permanent and cannot be undone. This will:
           </p>
           <ul
             style="
-              color: #666;
+              color: var(--text-secondary);
               margin-bottom: 20px;
               margin-left: 20px;
               font-size: 14px;
@@ -285,9 +430,7 @@
           </ul>
           <button
             class="button"
-            style="
-              background: linear-gradient(135deg, #dc3545 0%, #c82333 100%);
-            "
+            style="background: var(--gradient-error)"
             onclick="confirmDeleteAccount()"
           >
             🗑️ Delete Account
@@ -300,7 +443,7 @@
 
         <button
           class="quick-action"
-          onclick="window.location.href='/add-child.html'"
+          onclick="window.location.href = '/add-child.html'"
         >
           ➕ Add New Child
         </button>
@@ -338,15 +481,17 @@
     >
       <div
         style="
-          background: white;
+          background: var(--bg-secondary);
           padding: 30px;
           border-radius: 12px;
           max-width: 400px;
           width: 90%;
         "
       >
-        <h2 style="margin-top: 0">🔗 Redeem Share Code</h2>
-        <p style="color: #666; margin-bottom: 20px">
+        <h2 style="margin-top: 0; color: var(--text-primary)">
+          🔗 Redeem Share Code
+        </h2>
+        <p style="color: var(--text-secondary); margin-bottom: 20px">
           Enter the share code to get access to a child.
         </p>
         <form id="redeemCodeForm">
@@ -360,9 +505,11 @@
               style="
                 width: 100%;
                 padding: 12px;
-                border: 2px solid #e0e0e0;
+                border: 2px solid var(--border-color, #ddd);
                 border-radius: 6px;
                 font-size: 14px;
+                background-color: var(--input-bg);
+                color: var(--input-text);
               "
             />
           </div>
@@ -402,18 +549,21 @@
     >
       <div
         style="
-          background: white;
+          background: var(--bg-secondary);
           padding: 30px;
           border-radius: 12px;
           max-width: 400px;
           width: 90%;
         "
       >
-        <h2 style="margin-top: 0">🔗 Share Code</h2>
-        <p style="color: #666; margin-bottom: 20px" id="shareCodeChildName"></p>
+        <h2 style="margin-top: 0; color: var(--text-primary)">🔗 Share Code</h2>
+        <p
+          style="color: var(--text-secondary); margin-bottom: 20px"
+          id="shareCodeChildName"
+        ></p>
         <div
           style="
-            background: #f8f9fa;
+            background: var(--bg-tertiary);
             padding: 20px;
             border-radius: 8px;
             margin-bottom: 20px;
@@ -430,7 +580,7 @@
               style="
                 font-size: 24px;
                 font-weight: bold;
-                color: #333;
+                color: var(--text-primary);
                 letter-spacing: 2px;
               "
               id="shareCodeValue"
@@ -451,7 +601,13 @@
             </button>
           </div>
         </div>
-        <p style="color: #666; font-size: 14px; margin-bottom: 20px">
+        <p
+          style="
+            color: var(--text-secondary);
+            font-size: 14px;
+            margin-bottom: 20px;
+          "
+        >
           Share this code with another user. They can use it in Settings >
           Redeem Share Code to get access to this child.
           <br /><br />
@@ -478,6 +634,47 @@
       // Initialize burger menu
       initBurgerMenu({ includeHome: true });
 
+      // Initialize theme selector
+      function initThemeSelector() {
+        const currentTheme = window.getThemePreference();
+        const themeRadio = document.querySelector(
+          `input[name="theme"][value="${currentTheme}"]`,
+        );
+        if (themeRadio) {
+          themeRadio.checked = true;
+        }
+
+        // Add visual feedback for selected theme option
+        updateThemeOptionStyles();
+
+        // Listen for theme changes
+        document.querySelectorAll('input[name="theme"]').forEach((radio) => {
+          radio.addEventListener("change", (e) => {
+            window.setTheme(e.target.value);
+            updateThemeOptionStyles();
+          });
+        });
+      }
+
+      function updateThemeOptionStyles() {
+        const selectedValue = document.querySelector(
+          'input[name="theme"]:checked',
+        )?.value;
+        document.querySelectorAll(".theme-option").forEach((option) => {
+          const isSelected = option.dataset.theme === selectedValue;
+          if (isSelected) {
+            option.style.borderColor = "#667eea";
+            option.style.background = "rgba(102, 126, 234, 0.05)";
+          } else {
+            option.style.borderColor = "#e0e0e0";
+            option.style.background = "transparent";
+          }
+        });
+      }
+
+      // Initialize theme selector on load
+      initThemeSelector();
+
       let currentUser = null;
       let children = [];
 
@@ -533,14 +730,23 @@
         container.innerHTML = `
           <div class="children-list">
             ${children
-              .map(
-                (child) => `
+              .map((child) => {
+                // Get list of other users (excluding current user)
+                const otherUsers =
+                  child.parent_usernames && child.parent_usernames.length > 1
+                    ? child.parent_usernames.filter(
+                        (username) => username !== currentUser.username,
+                      )
+                    : [];
+
+                return `
               <div class="child-card">
-                <h3>👶 ${child.name}</h3>
+                <h3 style="margin: 0;">👶 ${child.name}</h3>
                 <div class="child-info">
                   <p><strong>Birth Date:</strong> ${formatDate(child.birth_time)}</p>
                   <p><strong>Birth Weight:</strong> ${child.birth_weight}g</p>
                   <p><strong>Added:</strong> ${formatDate(child.created_at)}</p>
+                  ${otherUsers.length > 0 ? `<p><strong>Shared with:</strong> ${otherUsers.join(", ")}</p>` : ""}
                 </div>
                 <div class="child-actions">
                   <button class="button secondary" onclick="editChild(${child.id})">
@@ -551,8 +757,8 @@
                   </button>
                 </div>
               </div>
-            `,
-              )
+            `;
+              })
               .join("")}
           </div>
         `;
@@ -568,12 +774,17 @@
       }
 
       function editChild(childId) {
-        // Redirect to a child edit page or show a modal
-        // For now, just show an alert
         const child = children.find((c) => c.id === childId);
-        if (child) {
-          alert(`Edit functionality for ${child.name} coming soon!`);
-        }
+        if (!child) return;
+
+        // Redirect to add-child page with child data in query params
+        const params = new URLSearchParams({
+          id: child.id,
+          name: child.name,
+          birth_time: child.birth_time,
+          birth_weight: child.birth_weight,
+        });
+        window.location.href = `/add-child.html?${params.toString()}`;
       }
 
       async function shareChild(childId) {

src/baby_monitor/static/sleep.html

@@ -4,6 +4,9 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Sleep - Baby Monitor</title>
+    <link rel="stylesheet" href="/dark-mode.css" />
+    <script src="/theme-init.js"></script>
+    <script src="/chart-theme.js"></script>
     <link rel="stylesheet" href="/menu.css" />
     <style>
       * {
@@ -16,7 +19,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background-color: #f0f0f0;
+        background-color: var(--bg-primary);
         min-height: 100vh;
         max-width: 800px;
         margin: 2rem auto;
@@ -24,26 +27,27 @@
       }
 
       .container {
-        background: white;
+        background: var(--bg-secondary);
         border-radius: 12px;
         box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
         padding: 40px;
       }
 
       h1 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
         font-size: 28px;
       }
 
       .subtitle {
-        color: #666;
+        color: var(--text-secondary);
         margin-bottom: 30px;
         font-size: 14px;
       }
 
       .button {
-        background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
         color: white;
         border: none;
         padding: 12px 24px;
@@ -79,13 +83,13 @@
       .loading {
         text-align: center;
         padding: 40px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state {
         text-align: center;
         padding: 60px 20px;
-        color: #666;
+        color: var(--text-secondary);
       }
 
       .empty-state-icon {
@@ -94,7 +98,7 @@
       }
 
       .empty-state h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 10px;
       }
 
@@ -105,12 +109,12 @@
       .chart-container {
         margin-bottom: 40px;
         padding: 20px;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
       }
 
       .chart-container h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -148,14 +152,14 @@
       }
 
       .stat-card {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         padding: 20px;
         border-radius: 8px;
         text-align: center;
       }
 
       .stat-card h3 {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 14px;
         font-weight: 600;
         text-transform: uppercase;
@@ -169,13 +173,13 @@
       }
 
       .list-container {
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
         padding: 20px;
       }
 
       .list-container h2 {
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 20px;
         font-size: 20px;
       }
@@ -186,14 +190,14 @@
       }
 
       .sleep-item {
-        background: white;
+        background: var(--bg-secondary);
         padding: 16px;
         border-radius: 6px;
         margin-bottom: 12px;
         display: flex;
         justify-content: space-between;
         align-items: center;
-        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
+        box-shadow: var(--shadow-sm);
       }
 
       .sleep-item:last-child {
@@ -206,12 +210,12 @@
 
       .sleep-child {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 4px;
       }
 
       .sleep-time {
-        color: #666;
+        color: var(--text-secondary);
         font-size: 14px;
         margin-bottom: 4px;
       }
@@ -252,23 +256,31 @@
 
       .controls label {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
       }
 
-      .controls select {
+      .controls select,
+      .controls input {
         padding: 8px 16px;
-        border: 1px solid #ddd;
+        border: 2px solid var(--border-color, #ddd);
         border-radius: 6px;
         font-size: 14px;
         cursor: pointer;
-        background: white;
+        background: var(--bg-secondary);
+        color: var(--text-primary);
       }
 
-      .controls select:focus {
+      .controls select:focus,
+      .controls input:focus {
         outline: none;
         border-color: #4facfe;
       }
 
+      .controls input[readonly] {
+        opacity: 0.6;
+        cursor: default;
+      }
+
       .badge {
         display: inline-block;
         padding: 4px 8px;
@@ -328,27 +340,33 @@
       let allChildren = [];
       let selectedChildId = "";
 
-      // Filter change handlers
-      document
-        .getElementById("childFilter")
-        .addEventListener("change", function () {
-          selectedChildId = this.value;
-          // Save selection to localStorage
-          if (selectedChildId) {
-            localStorage.setItem("lastSleepChildFilter", selectedChildId);
-          } else {
-            localStorage.removeItem("lastSleepChildFilter");
-          }
-          renderCharts();
-        });
+      // Filter change handlers (will be attached after children are loaded)
+      function attachChildFilterListener() {
+        const childFilter = document.getElementById("childFilter");
+        if (childFilter) {
+          childFilter.addEventListener("change", function () {
+            selectedChildId = this.value;
+            // Save selection to localStorage
+            if (selectedChildId) {
+              localStorage.setItem("lastSleepChildFilter", selectedChildId);
+            } else {
+              localStorage.removeItem("lastSleepChildFilter");
+            }
+            renderCharts();
+          });
+        }
+      }
 
-      document
-        .getElementById("timeRangeFilter")
-        .addEventListener("change", function () {
-          // Save selection to localStorage
-          localStorage.setItem("lastSleepTimeRange", this.value);
-          loadData();
-        });
+      function attachTimeRangeListener() {
+        const timeRangeFilter = document.getElementById("timeRangeFilter");
+        if (timeRangeFilter) {
+          timeRangeFilter.addEventListener("change", function () {
+            // Save selection to localStorage
+            localStorage.setItem("lastSleepTimeRange", this.value);
+            renderCharts();
+          });
+        }
+      }
 
       async function loadData() {
         try {
@@ -365,19 +383,51 @@
 
           allChildren = await childrenResponse.json();
 
-          // Populate child filter
-          const childFilter = document.getElementById("childFilter");
-          childFilter.innerHTML = '<option value="">All Children</option>';
-          allChildren.forEach((child) => {
-            const option = document.createElement("option");
-            option.value = child.id;
-            option.textContent = child.name;
-            childFilter.appendChild(option);
-          });
+          // Auto-select first child if available
+          if (allChildren.length > 0 && !selectedChildId) {
+            selectedChildId = allChildren[0].id;
+          }
+
+          // Populate child filter or show single child
+          const childFilterContainer = document.querySelector(".controls");
+          if (allChildren.length === 1) {
+            // Single child: show as read-only text
+            const child = allChildren[0];
+            childFilterContainer.innerHTML = `
+              <label for="childDisplay">Child:</label>
+              <input
+                type="text"
+                id="childDisplay"
+                value="${child.name}"
+                readonly
+              />
+
+              <label for="timeRangeFilter">Time Range:</label>
+              <select id="timeRangeFilter">
+                <option value="1">Last 24 hours</option>
+                <option value="3">Last 3 days</option>
+                <option value="7" selected>Last 7 days</option>
+                <option value="14">Last 14 days</option>
+                <option value="30">Last 30 days</option>
+                <option value="90">Last 90 days</option>
+              </select>
+            `;
+          } else {
+            // Multiple children: show dropdown
+            const childFilter = document.getElementById("childFilter");
+            childFilter.innerHTML = "";
+            allChildren.forEach((child) => {
+              const option = document.createElement("option");
+              option.value = child.id;
+              option.textContent = child.name;
+              childFilter.appendChild(option);
+            });
+          }
 
           // Restore last selected child from localStorage
           const lastChildId = localStorage.getItem("lastSleepChildFilter");
-          if (lastChildId) {
+          if (lastChildId && allChildren.length > 1) {
+            const childFilter = document.getElementById("childFilter");
             childFilter.value = lastChildId;
             selectedChildId = lastChildId;
           }
@@ -402,6 +452,14 @@
 
           allSleeps = await sleepResponse.json();
 
+          // Attach event listener for child filter if multiple children
+          if (allChildren.length > 1) {
+            attachChildFilterListener();
+          }
+
+          // Always attach time range listener after recreating the controls
+          attachTimeRangeListener();
+
           renderCharts();
         } catch (error) {
           console.error("Error loading data:", error);
@@ -432,19 +490,7 @@
           return matchesTimeRange && matchesChild;
         });
 
-        if (filteredSleeps.length === 0) {
-          document.getElementById("content").innerHTML = `
-            <div class="empty-state">
-              <div class="empty-state-icon">😴</div>
-              <h2>No Sleep Data</h2>
-              <p>Start tracking sleep sessions from the home page.</p>
-              <button class="button" onclick="window.location.href='/'">Go Home</button>
-            </div>
-          `;
-          return;
-        }
-
-        // Calculate stats
+        // Calculate stats (works with empty arrays too)
         const completedSleeps = filteredSleeps.filter(
           (sleep) => sleep.end_time,
         );
@@ -517,7 +563,10 @@
           </div>
 
           <div class="list-container">
-            <h2>Recent Sleep Sessions</h2>
+            <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px;">
+              <h2 style="margin: 0;">Recent Sleep Sessions</h2>
+              <button class="button" onclick="addManualSleep()" style="padding: 8px 16px; font-size: 14px;">➕ Add Manual Entry</button>
+            </div>
             <div class="sleep-list">
               ${filteredSleeps
                 .slice(0, 50)
@@ -846,7 +895,7 @@
               x: {
                 stacked: true,
               },
-              y: {
+              y: getChartScaleOptions("y", {
                 stacked: true,
                 beginAtZero: true,
                 title: {
@@ -862,7 +911,7 @@
                     }
                   },
                 },
-              },
+              }),
             },
             plugins: {
               legend: {
@@ -1007,14 +1056,14 @@
             responsive: true,
             maintainAspectRatio: false,
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 ticks: {
                   callback: function (value) {
                     return value + "m";
                   },
                 },
-              },
+              }),
             },
             plugins: {
               legend: {
@@ -1054,10 +1103,17 @@
               </div>
               <div class="sleep-duration">${durationText}</div>
             </div>
+            <div class="sleep-actions">
+              <button class="edit-button" onclick="window.location.href='/log-sleep.html?id=${sleep.id}'">Edit</button>
+            </div>
           </div>
         `;
       }
 
+      function addManualSleep() {
+        window.location.href = `/log-sleep.html`;
+      }
+
       async function logout() {
         try {
           await fetch("/api/logout", {
@@ -1077,6 +1133,16 @@
 
       // Load data on page load
       loadData();
+
+      // Listen for theme changes and update charts
+      window.addEventListener("themechange", () => {
+        const charts = [
+          barChartInstance,
+          durationChartInstance,
+          avgDurationChartInstance,
+        ].filter((c) => c);
+        updateChartsForTheme(charts);
+      });
     </script>
   </body>
 </html>

src/baby_monitor/static/theme-init.js

@@ -0,0 +1,87 @@
+/* Theme Initialization Script
+ * Handles theme detection and application based on localStorage preference or browser settings
+ * Must be loaded in <head> before page content to prevent flash of unstyled content
+ */
+
+(function () {
+  "use strict";
+
+  // Get saved theme preference from localStorage
+  const savedTheme = localStorage.getItem("theme-preference");
+
+  // Apply theme immediately to prevent FOUC (Flash of Unstyled Content)
+  function applyTheme(theme) {
+    const body = document.body || document.documentElement;
+
+    if (theme === "dark") {
+      body.classList.remove("light-mode");
+      body.classList.add("dark-mode");
+    } else if (theme === "light") {
+      body.classList.remove("dark-mode");
+      body.classList.add("light-mode");
+    } else {
+      // 'auto' mode - remove manual override classes
+      body.classList.remove("dark-mode", "light-mode");
+    }
+  }
+
+  // Apply theme based on preference
+  if (
+    savedTheme === "dark" ||
+    savedTheme === "light" ||
+    savedTheme === "auto"
+  ) {
+    applyTheme(savedTheme);
+  }
+  // If no preference saved, default to 'auto' (browser preference)
+
+  // Make theme switching function available globally
+  window.setTheme = function (theme) {
+    if (theme === "light" || theme === "dark" || theme === "auto") {
+      localStorage.setItem("theme-preference", theme);
+      applyTheme(theme);
+
+      // Trigger custom event for components that need to update (e.g., charts)
+      window.dispatchEvent(
+        new CustomEvent("themechange", { detail: { theme } }),
+      );
+    }
+  };
+
+  // Get current effective theme (resolves 'auto' to actual theme)
+  window.getEffectiveTheme = function () {
+    const savedTheme = localStorage.getItem("theme-preference");
+
+    if (savedTheme === "dark") return "dark";
+    if (savedTheme === "light") return "light";
+
+    // 'auto' or no preference - check system preference
+    if (
+      window.matchMedia &&
+      window.matchMedia("(prefers-color-scheme: dark)").matches
+    ) {
+      return "dark";
+    }
+    return "light";
+  };
+
+  // Get saved theme preference (returns 'light', 'dark', 'auto', or null)
+  window.getThemePreference = function () {
+    return localStorage.getItem("theme-preference") || "auto";
+  };
+
+  // Listen for system theme changes when in auto mode
+  if (window.matchMedia) {
+    const mediaQuery = window.matchMedia("(prefers-color-scheme: dark)");
+    mediaQuery.addEventListener("change", function (e) {
+      const savedTheme = localStorage.getItem("theme-preference");
+      // Only react to system changes if in auto mode
+      if (!savedTheme || savedTheme === "auto") {
+        // Trigger theme change event for components that need to update
+        window.dispatchEvent(
+          new CustomEvent("themechange", { detail: { theme: "auto" } }),
+        );
+      }
+    });
+  }
+})();