Merge pull request 'Make recent activity cards dynamic' (#45) from make-recent-activity-last-sleep-dynamic into main

Reviewed-on: https://gitea.lille-vemmelund.dk/brian/baby-monitor/pulls/45

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]

src/baby_monitor/main.py

@@ -143,6 +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/sleep.py

@@ -15,6 +15,7 @@ class CreateSleepRequest(BaseModel):
 class UpdateSleepRequest(BaseModel):
     """Request model for updating a sleep log."""
 
+    start_time: datetime | None = None
     end_time: datetime | None = None
 
 

src/baby_monitor/repositories/interfaces/sleep_repository_interface.py

@@ -32,6 +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

@@ -73,6 +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."""
@@ -80,6 +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/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.
+    Returns 200 if the service is ready to accept traffic, else 503.
-    This can include checks for database connectivity, external services, etc.
     """
-    # 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

@@ -112,6 +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>

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;
+        background: var(--bg-secondary);
-        border: 1px solid #ddd;
+        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;
+        border-bottom: 1px solid var(--border-lighter);
-        background: white;
+        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 {

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;
+        background: var(--bg-secondary);
-        border-bottom: 1px solid #eee;
+        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 {
@@ -356,6 +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 {
@@ -383,7 +396,6 @@
                   id="childDisplay"
                   value="${allChildren[0].name}"
                   readonly
-                  style="background-color: #f5f5f5; cursor: default; padding: 8px; border: 1px solid #ddd; border-radius: 4px; font-size: 14px;"
                 />
               `
                   : `
@@ -845,7 +857,7 @@
               },
             },
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 title: {
                   display: true,
@@ -861,10 +873,7 @@
                     size: 12,
                   },
                 },
-                grid: {
+              }),
-                  color: "rgba(0, 0, 0, 0.05)",
-                },
-              },
               x: {
                 ticks: {
                   font: {
@@ -1087,6 +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;
+        background: var(--bg-secondary);
-        border-bottom: 1px solid #eee;
+        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 {
@@ -387,29 +404,33 @@
       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>
+              <div class="empty-state-icon">👶</div>
-              <h2>No Feedings Yet</h2>
+              <h2>No Children Added</h2>
-              <p>Start tracking feeding sessions from the home page</p>
+              <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 {
+          return;
-          // Prepare chart data
+        }
-          const barChartData = prepareBarChartData(feedings);
-          const pieChartData = preparePieChartData(feedings);
-          const durationChartData = prepareDurationChartData(feedings);
 
-          // Build child dropdown options
+        // Prepare chart data (works with empty arrays too)
-          const childOptions = allChildren
+        const barChartData = prepareBarChartData(feedings);
-            .map(
+        const pieChartData = preparePieChartData(feedings);
-              (child) =>
+        const durationChartData = prepareDurationChartData(feedings);
-                `<option value="${child.id}" ${selectedChildId === child.id ? "selected" : ""}>${child.name}</option>`,
-            )
-            .join("");
 
-          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">
               ${
                 allChildren.length === 1
@@ -420,7 +441,6 @@
                   id="childDisplay"
                   value="${allChildren[0].name}"
                   readonly
-                  style="background-color: #f5f5f5; cursor: default; padding: 8px; border: 1px solid #ddd; border-radius: 4px; font-size: 14px;"
                 />
               `
                   : `
@@ -466,14 +486,13 @@
             </div>
           `;
 
-          // Render charts
+        // Render charts
-          renderBarChart(barChartData);
+        renderBarChart(barChartData);
-          renderPieChart(pieChartData);
+        renderPieChart(pieChartData);
-          renderDurationChart(durationChartData);
+        renderDurationChart(durationChartData);
 
-          // Render feeding list
+        // Render feeding list
-          renderFeedingList(feedings);
+        renderFeedingList(feedings);
-        }
       }
 
       function renderFeedingList(feedings) {
@@ -921,7 +940,7 @@
                   display: false,
                 },
               },
-              y: {
+              y: getChartScaleOptions("y", {
                 stacked: true,
                 beginAtZero: true,
                 title: {
@@ -940,10 +959,7 @@
                     return Math.round(value) + "m";
                   },
                 },
-                grid: {
+              }),
-                  color: "rgba(0, 0, 0, 0.05)",
-                },
-              },
             },
             plugins: {
               legend: {
@@ -1111,7 +1127,7 @@
               },
             },
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 title: {
                   display: true,
@@ -1127,11 +1143,8 @@
                     size: 12,
                   },
                 },
-                grid: {
+              }),
-                  color: "rgba(0, 0, 0, 0.05)",
+              x: getChartScaleOptions("x", {
-                },
-              },
-              x: {
                 title: {
                   display: true,
                   text: "Duration (minutes)",
@@ -1148,7 +1161,7 @@
                 grid: {
                   display: false,
                 },
-              },
+              }),
             },
           },
         });
@@ -1187,6 +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,
@@ -153,14 +170,17 @@
       }
       .sleep-button:hover {
         transform: translateY(-2px);
-        box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
+        box-shadow: 0 6px 20px rgba(79, 172, 254, 0.4);
-        background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
+        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;
@@ -170,13 +190,13 @@
       .recent-activity {
         margin-top: 2rem;
         padding: 1.5rem;
-        background: #f8f9fa;
+        background: var(--bg-tertiary);
         border-radius: 8px;
       }
       .recent-activity h3 {
         margin-top: 0;
         margin-bottom: 1rem;
-        color: #333;
+        color: var(--text-primary);
         font-size: 1.1rem;
       }
       .activity-grid {
@@ -185,7 +205,7 @@
         gap: 1rem;
       }
       .activity-card {
-        background: white;
+        background: var(--bg-secondary);
         padding: 1rem;
         border-radius: 6px;
         box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
@@ -196,12 +216,12 @@
       }
       .activity-card .type {
         font-weight: 600;
-        color: #333;
+        color: var(--text-primary);
         margin-bottom: 0.25rem;
       }
       .activity-card .time {
         font-size: 0.85rem;
-        color: #666;
+        color: var(--text-secondary);
       }
       .activity-card .details {
         font-size: 0.85rem;
@@ -286,6 +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";
@@ -308,11 +331,6 @@
             }
           })
           .then((user) => {
-            // Initialize burger menu
-            initBurgerMenu({
-              includeHome: true,
-            });
-
             // Check if user has any children
             return fetch("/api/children", {
               headers: {
@@ -396,7 +414,7 @@
             if (feedings.length > 0) {
               // Calculate the most recent feeding session
               let sessionStart = feedings[0].start_time;
-              let sessionEnd = feedings[0].end_time || feedings[0].start_time;
+              let sessionEnd = feedings[0].end_time;
               let sessionChildId = feedings[0].child_id;
               let sessionEntries = [feedings[0]];
 
@@ -631,7 +649,7 @@
             <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">${formatTime(lastFeeding.start_time)}</div>
+              <div class="time">${lastFeeding.end_time ? `stopped ${formatTime(lastFeeding.end_time)}` : `started ${formatTime(lastFeeding.start_time)}`}</div>
               <div class="details">
                 ${lastFeeding.feeding_types_string ? `${lastFeeding.feeding_types_string}` : ""}
                 ${lastFeeding.feeding_types_string && lastFeeding.accumulated_minutes ? " • " : ""}
@@ -653,7 +671,7 @@
             <a href="/sleep.html" class="activity-card" style="text-decoration:none; color:inherit;">
               <div class="icon">😴</div>
               <div class="type">Last Sleep</div>
-              <div class="time">${formatTime(lastSleep.start_time)}</div>
+              <div class="time">${lastSleep.end_time ? `stopped ${formatTime(lastSleep.end_time)}` : `started ${formatTime(lastSleep.start_time)}`}</div>
               <div class="details">
                 Duration: ${lastSleep.end_time ? calculateDuration(lastSleep.start_time, lastSleep.end_time) : "ongoing"}
               </div>

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=getReturnUrl()"
+          onclick="window.location.href = getReturnUrl()"
         >
           Cancel
         </button>
@@ -299,7 +309,6 @@
                   id="childName"
                   value="${child.name}"
                   readonly
-                  style="background-color: #f5f5f5; cursor: default;"
                 />
                 <input type="hidden" id="childSelect" name="childSelect" value="${child.id}" />
               `;

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>
@@ -281,7 +291,6 @@
                   id="childName"
                   value="${child.name}"
                   readonly
-                  style="background-color: #f5f5f5; cursor: default;"
                 />
                 <input type="hidden" id="childId" name="childId" value="${child.id}" />
               `;

src/baby_monitor/static/log-sleep.html

@@ -4,6 +4,8 @@
     <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;
@@ -15,7 +17,7 @@
         font-family:
           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
           Cantarell, sans-serif;
-        background: linear-gradient(135deg, #4facfe 0%, #00f2fe 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: #4facfe;
       }
 
+      input[readonly] {
+        opacity: 0.6;
+        cursor: default;
+      }
+
       .button {
-        background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+        background: var(--gradient-blue);
+        background-color: #4facfe;
         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>
@@ -271,7 +281,6 @@
                   id="childName"
                   value="${child.name}"
                   readonly
-                  style="background-color: #f5f5f5; cursor: default;"
                 />
                 <input type="hidden" id="childId" name="childId" value="${child.id}" />
               `;

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;
+  background: var(--bg-secondary, #ffffff);
-  box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
+  box-shadow: var(--shadow-md, 2px 0 10px rgba(0, 0, 0, 0.1));
-  transition: left 0.3s;
+  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="
+            style="background: var(--gradient-error)"
-              background: linear-gradient(135deg, #dc3545 0%, #c82333 100%);
-            "
             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>
+        <h2 style="margin-top: 0; color: var(--text-primary)">
-        <p style="color: #666; margin-bottom: 20px">
+          🔗 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>
+        <h2 style="margin-top: 0; color: var(--text-primary)">🔗 Share Code</h2>
-        <p style="color: #666; margin-bottom: 20px" id="shareCodeChildName"></p>
+        <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 = [];
 

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;
@@ -388,7 +400,6 @@
                 id="childDisplay"
                 value="${child.name}"
                 readonly
-                style="background-color: #f5f5f5; cursor: default; padding: 8px; border: 1px solid #ddd; border-radius: 4px; font-size: 14px;"
               />
 
               <label for="timeRangeFilter">Time Range:</label>
@@ -479,19 +490,7 @@
           return matchesTimeRange && matchesChild;
         });
 
-        if (filteredSleeps.length === 0) {
+        // Calculate stats (works with empty arrays too)
-          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
         const completedSleeps = filteredSleeps.filter(
           (sleep) => sleep.end_time,
         );
@@ -896,7 +895,7 @@
               x: {
                 stacked: true,
               },
-              y: {
+              y: getChartScaleOptions("y", {
                 stacked: true,
                 beginAtZero: true,
                 title: {
@@ -912,7 +911,7 @@
                     }
                   },
                 },
-              },
+              }),
             },
             plugins: {
               legend: {
@@ -1057,14 +1056,14 @@
             responsive: true,
             maintainAspectRatio: false,
             scales: {
-              y: {
+              y: getChartScaleOptions("y", {
                 beginAtZero: true,
                 ticks: {
                   callback: function (value) {
                     return value + "m";
                   },
                 },
-              },
+              }),
             },
             plugins: {
               legend: {
@@ -1134,6 +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" } }),
+        );
+      }
+    });
+  }
+})();