diff --git a/frontend-modern/src/App.tsx b/frontend-modern/src/App.tsx
index 16fe5739e..3c61da123 100644
--- a/frontend-modern/src/App.tsx
+++ b/frontend-modern/src/App.tsx
@@ -73,13 +73,8 @@ function App() {
   // Version info
   const [versionInfo, setVersionInfo] = createSignal<VersionInfo | null>(null);
   
-  // Dark mode - check localStorage first, only use system preference if never set
-  const savedDarkMode = localStorage.getItem(STORAGE_KEYS.DARK_MODE);
-  const [darkMode, setDarkMode] = createSignal(
-    savedDarkMode !== null 
-      ? savedDarkMode === 'true'
-      : window.matchMedia('(prefers-color-scheme: dark)').matches
-  );
+  // Dark mode - only apply user preferences after authentication
+  const [darkMode, setDarkMode] = createSignal(false);
   
   // Toggle dark mode
   const toggleDarkMode = () => {
@@ -94,12 +89,7 @@ function App() {
     logger.info('Theme changed', { mode: newMode ? 'dark' : 'light' });
   };
   
-  // Initialize dark mode - ensure it matches the signal
-  if (darkMode()) {
-    document.documentElement.classList.add('dark');
-  } else {
-    document.documentElement.classList.remove('dark');
-  }
+  // Don't initialize dark mode here - will be handled based on auth state
   
   // Check auth on mount
   onMount(async () => {
@@ -146,12 +136,36 @@ function App() {
         setNeedsAuth(false);
         // Only initialize WebSocket after successful auth check
         setWsStore(getGlobalWebSocketStore());
+        
+        // Apply user's theme preference only after successful authentication
+        const savedDarkMode = localStorage.getItem(STORAGE_KEYS.DARK_MODE);
+        const prefersDark = savedDarkMode !== null 
+          ? savedDarkMode === 'true'
+          : window.matchMedia('(prefers-color-scheme: dark)').matches;
+        setDarkMode(prefersDark);
+        if (prefersDark) {
+          document.documentElement.classList.add('dark');
+        } else {
+          document.documentElement.classList.remove('dark');
+        }
       }
     } catch (error) {
       console.error('Auth check error:', error);
       // On error, try to proceed without auth
       setNeedsAuth(false);
       setWsStore(getGlobalWebSocketStore());
+      
+      // Apply theme preference if we're proceeding without auth
+      const savedDarkMode = localStorage.getItem(STORAGE_KEYS.DARK_MODE);
+      const prefersDark = savedDarkMode !== null 
+        ? savedDarkMode === 'true'
+        : window.matchMedia('(prefers-color-scheme: dark)').matches;
+      setDarkMode(prefersDark);
+      if (prefersDark) {
+        document.documentElement.classList.add('dark');
+      } else {
+        document.documentElement.classList.remove('dark');
+      }
     } finally {
       setIsLoading(false);
     }
diff --git a/frontend-modern/src/components/FirstRunSetup.tsx b/frontend-modern/src/components/FirstRunSetup.tsx
index 0fcc9da0a..10c670e12 100644
--- a/frontend-modern/src/components/FirstRunSetup.tsx
+++ b/frontend-modern/src/components/FirstRunSetup.tsx
@@ -16,16 +16,9 @@ export const FirstRunSetup: Component = () => {
   const [savedToken, setSavedToken] = createSignal('');
   const [copied, setCopied] = createSignal<'password' | 'token' | null>(null);
   
-  // Additional setup options
-  const [darkMode, setDarkMode] = createSignal(
-    window.matchMedia('(prefers-color-scheme: dark)').matches
-  );
-  
   onMount(() => {
-    // Apply dark mode immediately if selected
-    if (darkMode()) {
-      document.documentElement.classList.add('dark');
-    }
+    // Force dark mode for setup screen
+    document.documentElement.classList.add('dark');
   });
 
   const generatePassword = () => {
@@ -80,8 +73,7 @@ export const FirstRunSetup: Component = () => {
         body: JSON.stringify({
           username: username(),
           password: finalPassword,
-          apiToken: token,
-          darkMode: darkMode()
+          apiToken: token
         })
       });
       
@@ -103,8 +95,6 @@ export const FirstRunSetup: Component = () => {
       setSavedPassword(useCustomPassword() ? password() : generatedPassword());
       setSavedToken(token);
       
-      // Apply settings - use consistent storage key
-      localStorage.setItem('darkMode', String(darkMode()));
       
       // Show credentials
       setShowCredentials(true);
@@ -263,44 +253,6 @@ IMPORTANT: Keep these credentials secure!
                   </Show>
                 </div>
 
-                {/* Additional Settings */}
-                <div class="space-y-4">
-                  <h3 class="text-sm font-medium text-gray-700 dark:text-gray-300">
-                    Initial Configuration
-                  </h3>
-                  
-                  {/* Dark Mode */}
-                  <div class="flex items-center justify-between">
-                    <div>
-                      <label class="text-sm text-gray-700 dark:text-gray-300">
-                        Dark Mode
-                      </label>
-                      <p class="text-xs text-gray-500 dark:text-gray-500">
-                        Use dark theme for the dashboard
-                      </p>
-                    </div>
-                    <button
-                      type="button"
-                      onClick={() => {
-                        setDarkMode(!darkMode());
-                        if (!darkMode()) {
-                          document.documentElement.classList.remove('dark');
-                        } else {
-                          document.documentElement.classList.add('dark');
-                        }
-                      }}
-                      class={`relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 ${
-                        darkMode() ? 'bg-blue-600' : 'bg-gray-200 dark:bg-gray-700'
-                      }`}
-                    >
-                      <span
-                        class={`pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out ${
-                          darkMode() ? 'translate-x-5' : 'translate-x-0'
-                        }`}
-                      />
-                    </button>
-                  </div>
-                </div>
 
                 {/* Info Box */}
                 <div class="bg-gray-50 dark:bg-gray-900 rounded-lg p-4 space-y-2">
diff --git a/frontend-modern/src/components/Login.tsx b/frontend-modern/src/components/Login.tsx
index 533e6ecf7..269275eb5 100644
--- a/frontend-modern/src/components/Login.tsx
+++ b/frontend-modern/src/components/Login.tsx
@@ -1,6 +1,5 @@
 import { Component, createSignal, Show, onMount, lazy, Suspense } from 'solid-js';
 import { setBasicAuth } from '@/utils/apiClient';
-import { STORAGE_KEYS } from '@/constants';
 
 // Force include FirstRunSetup with lazy loading
 const FirstRunSetup = lazy(() => import('./FirstRunSetup').then(m => ({ default: m.FirstRunSetup })));
@@ -18,13 +17,8 @@ export const Login: Component<LoginProps> = (props) => {
   const [loadingAuth, setLoadingAuth] = createSignal(true);
   
   onMount(async () => {
-    // Apply saved theme preference
-    const savedTheme = localStorage.getItem(STORAGE_KEYS.DARK_MODE);
-    if (savedTheme === 'true') {
-      document.documentElement.classList.add('dark');
-    } else {
-      document.documentElement.classList.remove('dark');
-    }
+    // Force dark mode for login screen
+    document.documentElement.classList.add('dark');
     
     console.log('[Login] Starting auth check...');
     try {