diff --git a/public/admin.js b/public/admin.js
index a616e0d..3c30a29 100644
--- a/public/admin.js
+++ b/public/admin.js
@@ -705,7 +705,13 @@ function initializeTheme() {
 }
 
 function applyTheme(theme) {
-    document.documentElement.setAttribute('data-theme', theme);
+    if (theme === 'auto') {
+        // Detect system preference and apply appropriate theme
+        const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+        document.documentElement.setAttribute('data-theme', prefersDark ? 'dark' : 'light');
+    } else {
+        document.documentElement.setAttribute('data-theme', theme);
+    }
 }
 
 function updateThemeIcon(theme, iconElement) {
diff --git a/public/app-mapbox.js b/public/app-mapbox.js
index 55d74d6..bea752e 100644
--- a/public/app-mapbox.js
+++ b/public/app-mapbox.js
@@ -617,7 +617,13 @@ function initializeTheme() {
 }
 
 function applyTheme(theme) {
-    document.documentElement.setAttribute('data-theme', theme);
+    if (theme === 'auto') {
+        // Detect system preference and apply appropriate theme
+        const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+        document.documentElement.setAttribute('data-theme', prefersDark ? 'dark' : 'light');
+    } else {
+        document.documentElement.setAttribute('data-theme', theme);
+    }
 }
 
 function updateThemeIcon(theme, iconElement) {
diff --git a/public/privacy.html b/public/privacy.html
index 6b56e18..b9397b1 100644
--- a/public/privacy.html
+++ b/public/privacy.html
@@ -165,7 +165,13 @@
         }
         
         function applyTheme(theme) {
-            document.documentElement.setAttribute('data-theme', theme);
+            if (theme === 'auto') {
+                // Detect system preference and apply appropriate theme
+                const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+                document.documentElement.setAttribute('data-theme', prefersDark ? 'dark' : 'light');
+            } else {
+                document.documentElement.setAttribute('data-theme', theme);
+            }
         }
         
         function updateThemeIcon(theme, iconElement) {