diff --git a/apps/marketplace/src/app/layout.tsx b/apps/marketplace/src/app/layout.tsx
index 470c91e..977c398 100644
--- a/apps/marketplace/src/app/layout.tsx
+++ b/apps/marketplace/src/app/layout.tsx
@@ -17,6 +17,14 @@ export default function RootLayout({ children }: { children: React.ReactNode })
   const language = getMarketplaceLanguage()
   return (
     <html lang={language} dir={language === 'ar' ? 'rtl' : 'ltr'} suppressHydrationWarning>
+      <head>
+        {/* Runs before hydration to prevent flash of wrong theme */}
+        <script
+          dangerouslySetInnerHTML={{
+            __html: `(function(){try{var t=document.cookie.split(';').map(function(c){return c.trim()}).find(function(c){return c.startsWith('rentaldrivego-theme=')});if(t)t=t.split('=')[1];if(!t)t=localStorage.getItem('rentaldrivego-theme');if(t==='dark'){document.documentElement.classList.add('dark');document.documentElement.style.colorScheme='dark';}}catch(e){}})()`,
+          }}
+        />
+      </head>
       <body suppressHydrationWarning>
         <MarketplaceShell initialLanguage={language}>{children}</MarketplaceShell>
       </body>
diff --git a/apps/marketplace/src/components/MarketplaceShell.tsx b/apps/marketplace/src/components/MarketplaceShell.tsx
index 1fb9d26..516d3d3 100644
--- a/apps/marketplace/src/components/MarketplaceShell.tsx
+++ b/apps/marketplace/src/components/MarketplaceShell.tsx
@@ -328,9 +328,12 @@ export default function MarketplaceShell({
 
   useEffect(() => {
     document.documentElement.classList.toggle('dark', theme === 'dark')
+    document.documentElement.style.colorScheme = theme === 'dark' ? 'dark' : 'light'
     document.body.dataset.theme = theme
-    writeScopedPreference(SHARED_THEME_KEY, theme, ['marketplace-theme'])
-  }, [theme])
+    if (hydrated) {
+      writeScopedPreference(SHARED_THEME_KEY, theme, ['marketplace-theme'])
+    }
+  }, [theme, hydrated])
 
   const value = useMemo(
     () => ({ language, theme, dict: dictionaries[language], companyName, setLanguage: applyLanguage, setTheme: applyTheme }),
