diff --git a/resources/css/app.css b/resources/css/app.css
index fb27d0c..efc1407 100644
--- a/resources/css/app.css
+++ b/resources/css/app.css
@@ -511,6 +511,20 @@ h4,
     --sidebar-ring: oklch(0.439 0 0);
 }
 
+html.guest-theme {
+    --background: var(--guest-background);
+    --card: var(--guest-surface);
+    --popover: var(--guest-surface);
+    background-color: var(--guest-background);
+}
+
+html.guest-theme.dark {
+    --background: var(--guest-background);
+    --card: var(--guest-surface);
+    --popover: var(--guest-surface);
+    background-color: var(--guest-background);
+}
+
 @keyframes mobile-shimmer {
     0% {
         background-position: -200% 0;
diff --git a/resources/js/admin/i18n/locales/de/management.json b/resources/js/admin/i18n/locales/de/management.json
index c62a5f9..b07e7c3 100644
--- a/resources/js/admin/i18n/locales/de/management.json
+++ b/resources/js/admin/i18n/locales/de/management.json
@@ -1920,9 +1920,17 @@
       "previewSubtitle": "Aktuelle Farben & Schriften",
       "primary": "Primärfarbe",
       "accent": "Akzentfarbe",
+      "background": "Hintergrund",
+      "surface": "Fläche",
+      "mode": "Theme",
+      "modeLight": "Hell",
+      "modeAuto": "Auto",
+      "modeDark": "Dunkel",
       "colors": "Farben",
       "primaryColor": "Primärfarbe",
       "accentColor": "Akzentfarbe",
+      "backgroundColor": "Hintergrundfarbe",
+      "surfaceColor": "Flächenfarbe",
       "fonts": "Schriften",
       "headingFont": "Überschrift-Schrift",
       "headingFontPlaceholder": "SF Pro Display",
diff --git a/resources/js/admin/i18n/locales/en/management.json b/resources/js/admin/i18n/locales/en/management.json
index 9a9c827..29b3349 100644
--- a/resources/js/admin/i18n/locales/en/management.json
+++ b/resources/js/admin/i18n/locales/en/management.json
@@ -1924,9 +1924,17 @@
       "previewSubtitle": "Current colors & fonts",
       "primary": "Primary",
       "accent": "Accent",
+      "background": "Background",
+      "surface": "Surface",
+      "mode": "Theme",
+      "modeLight": "Light",
+      "modeAuto": "Auto",
+      "modeDark": "Dark",
       "colors": "Colors",
       "primaryColor": "Primary color",
       "accentColor": "Accent color",
+      "backgroundColor": "Background color",
+      "surfaceColor": "Surface color",
       "fonts": "Fonts",
       "headingFont": "Headline font",
       "headingFontPlaceholder": "SF Pro Display",
diff --git a/resources/js/admin/lib/__tests__/brandingForm.test.ts b/resources/js/admin/lib/__tests__/brandingForm.test.ts
new file mode 100644
index 0000000..3854114
--- /dev/null
+++ b/resources/js/admin/lib/__tests__/brandingForm.test.ts
@@ -0,0 +1,56 @@
+import { describe, expect, it } from 'vitest';
+import { extractBrandingForm } from '../brandingForm';
+
+const defaults = {
+  primary: '#111111',
+  accent: '#222222',
+  background: '#ffffff',
+  surface: '#f0f0f0',
+  mode: 'auto' as const,
+};
+
+describe('extractBrandingForm', () => {
+  it('prefers palette values when available', () => {
+    const settings = {
+      branding: {
+        palette: {
+          primary: '#aa0000',
+          secondary: '#00aa00',
+          background: '#000000',
+          surface: '#111111',
+        },
+        primary_color: '#bbbbbb',
+        secondary_color: '#cccccc',
+        background_color: '#dddddd',
+        surface_color: '#eeeeee',
+        mode: 'dark',
+      },
+    };
+
+    const result = extractBrandingForm(settings, defaults);
+
+    expect(result.primary).toBe('#aa0000');
+    expect(result.accent).toBe('#00aa00');
+    expect(result.background).toBe('#000000');
+    expect(result.surface).toBe('#111111');
+    expect(result.mode).toBe('dark');
+  });
+
+  it('falls back to legacy keys and defaults', () => {
+    const settings = {
+      branding: {
+        accent_color: '#123456',
+        background_color: '#abcdef',
+        mode: 'light',
+      },
+    };
+
+    const result = extractBrandingForm(settings, defaults);
+
+    expect(result.primary).toBe(defaults.primary);
+    expect(result.accent).toBe('#123456');
+    expect(result.background).toBe('#abcdef');
+    expect(result.surface).toBe('#abcdef');
+    expect(result.mode).toBe('light');
+  });
+});
diff --git a/resources/js/admin/lib/brandingForm.ts b/resources/js/admin/lib/brandingForm.ts
new file mode 100644
index 0000000..6658fbf
--- /dev/null
+++ b/resources/js/admin/lib/brandingForm.ts
@@ -0,0 +1,56 @@
+export type BrandingFormValues = {
+  primary: string;
+  accent: string;
+  background: string;
+  surface: string;
+  headingFont: string;
+  bodyFont: string;
+  logoDataUrl: string;
+  mode: 'light' | 'dark' | 'auto';
+};
+
+export type BrandingFormDefaults = Pick<BrandingFormValues, 'primary' | 'accent' | 'background' | 'surface' | 'mode'>;
+
+type BrandingRecord = Record<string, unknown>;
+
+const isRecord = (value: unknown): value is BrandingRecord =>
+  Boolean(value) && typeof value === 'object' && !Array.isArray(value);
+
+const readHexColor = (value: unknown, fallback: string): string => {
+  if (typeof value === 'string' && value.trim().startsWith('#')) {
+    return value.trim();
+  }
+  return fallback;
+};
+
+export function extractBrandingForm(settings: unknown, defaults: BrandingFormDefaults): BrandingFormValues {
+  const settingsRecord = isRecord(settings) ? settings : {};
+  const branding = isRecord(settingsRecord.branding) ? (settingsRecord.branding as BrandingRecord) : settingsRecord;
+  const palette = isRecord(branding.palette) ? (branding.palette as BrandingRecord) : {};
+  const typography = isRecord(branding.typography) ? (branding.typography as BrandingRecord) : {};
+
+  const primary = readHexColor(palette.primary, readHexColor(branding.primary_color, defaults.primary));
+  const accent = readHexColor(
+    palette.secondary,
+    readHexColor(branding.secondary_color, readHexColor(branding.accent_color, defaults.accent))
+  );
+  const background = readHexColor(palette.background, readHexColor(branding.background_color, defaults.background));
+  const surface = readHexColor(palette.surface, readHexColor(branding.surface_color, background));
+
+  const headingFont = typeof typography.heading === 'string' ? typography.heading : (branding.heading_font as string | undefined);
+  const bodyFont = typeof typography.body === 'string' ? typography.body : (branding.body_font as string | undefined);
+  const mode = branding.mode === 'light' || branding.mode === 'dark' || branding.mode === 'auto'
+    ? branding.mode
+    : defaults.mode;
+
+  return {
+    primary,
+    accent,
+    background,
+    surface,
+    headingFont: headingFont ?? '',
+    bodyFont: bodyFont ?? '',
+    logoDataUrl: typeof branding.logo_data_url === 'string' ? branding.logo_data_url : '',
+    mode,
+  };
+}
diff --git a/resources/js/admin/mobile/BrandingPage.tsx b/resources/js/admin/mobile/BrandingPage.tsx
index d50be7f..2e9cdf4 100644
--- a/resources/js/admin/mobile/BrandingPage.tsx
+++ b/resources/js/admin/mobile/BrandingPage.tsx
@@ -16,13 +16,22 @@ import toast from 'react-hot-toast';
 import { adminPath } from '../constants';
 import { useBackNavigation } from './hooks/useBackNavigation';
 import { ADMIN_COLORS, ADMIN_GRADIENTS, useAdminTheme } from './theme';
+import { extractBrandingForm, type BrandingFormValues } from '../lib/brandingForm';
+import { getContrastingTextColor } from '@/guest/lib/color';
 
-type BrandingForm = {
-  primary: string;
-  accent: string;
-  headingFont: string;
-  bodyFont: string;
-  logoDataUrl: string;
+const BRANDING_FORM_DEFAULTS = {
+  primary: ADMIN_COLORS.primary,
+  accent: ADMIN_COLORS.accent,
+  background: '#ffffff',
+  surface: '#ffffff',
+  mode: 'auto' as const,
+};
+
+const BRANDING_FORM_BASE: BrandingFormValues = {
+  ...BRANDING_FORM_DEFAULTS,
+  headingFont: '',
+  bodyFont: '',
+  logoDataUrl: '',
 };
 
 type WatermarkPosition =
@@ -58,13 +67,7 @@ export default function MobileBrandingPage() {
   const { textStrong, muted, subtle, border, primary, accentSoft, danger, surfaceMuted, surface } = useAdminTheme();
 
   const [event, setEvent] = React.useState<TenantEvent | null>(null);
-  const [form, setForm] = React.useState<BrandingForm>({
-    primary: ADMIN_COLORS.primary,
-    accent: ADMIN_COLORS.accent,
-    headingFont: '',
-    bodyFont: '',
-    logoDataUrl: '',
-  });
+  const [form, setForm] = React.useState<BrandingFormValues>(BRANDING_FORM_BASE);
   const [watermarkForm, setWatermarkForm] = React.useState<WatermarkForm>({
     mode: 'base',
     assetPath: '',
@@ -94,7 +97,7 @@ export default function MobileBrandingPage() {
       try {
         const data = await getEvent(slug);
         setEvent(data);
-        setForm(extractBranding(data));
+        setForm(extractBrandingForm(data.settings ?? {}, BRANDING_FORM_DEFAULTS));
         setWatermarkForm(extractWatermark(data));
         setError(null);
       } catch (err) {
@@ -122,6 +125,7 @@ export default function MobileBrandingPage() {
   const previewTitle = event ? renderName(event.name) : t('events.placeholders.untitled', 'Unbenanntes Event');
   const previewHeadingFont = form.headingFont || 'Fraunces';
   const previewBodyFont = form.bodyFont || 'Manrope';
+  const previewSurfaceText = getContrastingTextColor(form.surface, '#ffffff', '#0f172a');
   const watermarkAllowed = event?.package?.watermark_allowed !== false;
   const brandingAllowed = isBrandingAllowed(event ?? null);
   const watermarkLocked = watermarkAllowed && !brandingAllowed;
@@ -158,9 +162,13 @@ export default function MobileBrandingPage() {
       settings.branding = {
         ...(typeof settings.branding === 'object' ? (settings.branding as Record<string, unknown>) : {}),
         primary_color: form.primary,
+        secondary_color: form.accent,
         accent_color: form.accent,
+        background_color: form.background,
+        surface_color: form.surface,
         heading_font: form.headingFont,
         body_font: form.bodyFont,
+        mode: form.mode,
         typography: {
           ...(typeof (settings.branding as Record<string, unknown> | undefined)?.typography === 'object'
             ? ((settings.branding as Record<string, unknown>).typography as Record<string, unknown>)
@@ -174,6 +182,8 @@ export default function MobileBrandingPage() {
             : {}),
           primary: form.primary,
           secondary: form.accent,
+          background: form.background,
+          surface: form.surface,
         },
         logo_data_url: form.logoDataUrl || null,
         logo: form.logoDataUrl
@@ -217,7 +227,7 @@ export default function MobileBrandingPage() {
 
   function handleReset() {
     if (event) {
-      setForm(extractBranding(event));
+      setForm(extractBrandingForm(event.settings ?? {}, BRANDING_FORM_DEFAULTS));
       setWatermarkForm(extractWatermark(event));
     }
   }
@@ -435,25 +445,50 @@ export default function MobileBrandingPage() {
             <Text fontSize="$sm" fontWeight="700" color={textStrong}>
               {t('events.branding.previewTitle', 'Guest App Preview')}
             </Text>
-            <YStack borderRadius={16} borderWidth={1} borderColor={border} backgroundColor={surfaceMuted} padding="$3" space="$2" alignItems="center">
-              <YStack width="100%" borderRadius={12} backgroundColor={surface} borderWidth={1} borderColor={border} overflow="hidden">
+            <YStack borderRadius={16} borderWidth={1} borderColor={border} backgroundColor={form.background} padding="$3" space="$2" alignItems="center">
+              <YStack width="100%" borderRadius={12} backgroundColor={form.surface} borderWidth={1} borderColor={border} overflow="hidden">
                 <YStack backgroundColor={form.primary} height={64} />
                 <YStack padding="$3" space="$1.5">
-                  <Text fontSize="$md" fontWeight="800" color={textStrong} style={{ fontFamily: previewHeadingFont }}>
+                  <Text fontSize="$md" fontWeight="800" color={previewSurfaceText} style={{ fontFamily: previewHeadingFont }}>
                     {previewTitle}
                   </Text>
-                  <Text fontSize="$sm" color={muted} style={{ fontFamily: previewBodyFont }}>
+                  <Text fontSize="$sm" color={previewSurfaceText} style={{ fontFamily: previewBodyFont, opacity: 0.7 }}>
                     {t('events.branding.previewSubtitle', 'Aktuelle Farben & Schriften')}
                   </Text>
                   <XStack space="$2" marginTop="$1">
                     <ColorSwatch color={form.primary} label={t('events.branding.primary', 'Primary')} />
                     <ColorSwatch color={form.accent} label={t('events.branding.accent', 'Accent')} />
+                    <ColorSwatch color={form.background} label={t('events.branding.background', 'Background')} />
+                    <ColorSwatch color={form.surface} label={t('events.branding.surface', 'Surface')} />
                   </XStack>
                 </YStack>
               </YStack>
             </YStack>
           </MobileCard>
 
+          <MobileCard space="$3">
+            <Text fontSize="$md" fontWeight="800" color={textStrong}>
+              {t('events.branding.mode', 'Theme')}
+            </Text>
+            <XStack space="$2">
+              <ModeButton
+                label={t('events.branding.modeLight', 'Light')}
+                active={form.mode === 'light'}
+                onPress={() => setForm((prev) => ({ ...prev, mode: 'light' }))}
+              />
+              <ModeButton
+                label={t('events.branding.modeAuto', 'Auto')}
+                active={form.mode === 'auto'}
+                onPress={() => setForm((prev) => ({ ...prev, mode: 'auto' }))}
+              />
+              <ModeButton
+                label={t('events.branding.modeDark', 'Dark')}
+                active={form.mode === 'dark'}
+                onPress={() => setForm((prev) => ({ ...prev, mode: 'dark' }))}
+              />
+            </XStack>
+          </MobileCard>
+
           <MobileCard space="$3">
             <Text fontSize="$md" fontWeight="800" color={textStrong}>
               {t('events.branding.colors', 'Colors')}
@@ -468,6 +503,16 @@ export default function MobileBrandingPage() {
               value={form.accent}
               onChange={(value) => setForm((prev) => ({ ...prev, accent: value }))}
             />
+            <ColorField
+              label={t('events.branding.backgroundColor', 'Background Color')}
+              value={form.background}
+              onChange={(value) => setForm((prev) => ({ ...prev, background: value }))}
+            />
+            <ColorField
+              label={t('events.branding.surfaceColor', 'Surface Color')}
+              value={form.surface}
+              onChange={(value) => setForm((prev) => ({ ...prev, surface: value }))}
+            />
           </MobileCard>
 
           <MobileCard space="$3">
@@ -671,26 +716,6 @@ export default function MobileBrandingPage() {
   );
 }
 
-function extractBranding(event: TenantEvent): BrandingForm {
-  const source = (event.settings as Record<string, unknown>) ?? {};
-  const branding = (source.branding as Record<string, unknown>) ?? source;
-  const readColor = (key: string, fallback: string) => {
-    const value = branding[key];
-    return typeof value === 'string' && value.startsWith('#') ? value : fallback;
-  };
-  const readText = (key: string) => {
-    const value = branding[key];
-    return typeof value === 'string' ? value : '';
-  };
-  return {
-    primary: readColor('primary_color', ADMIN_COLORS.primary),
-    accent: readColor('accent_color', ADMIN_COLORS.accent),
-    headingFont: readText('heading_font'),
-    bodyFont: readText('body_font'),
-    logoDataUrl: readText('logo_data_url'),
-  };
-}
-
 function extractWatermark(event: TenantEvent): WatermarkForm {
   const settings = (event.settings as Record<string, unknown>) ?? {};
   const wm = (settings.watermark as Record<string, unknown>) ?? {};
@@ -1078,3 +1103,24 @@ function TabButton({ label, active, onPress }: { label: string; active: boolean;
     </Pressable>
   );
 }
+
+function ModeButton({ label, active, onPress }: { label: string; active: boolean; onPress: () => void }) {
+  const { backdrop, surfaceMuted, border, surface } = useAdminTheme();
+  return (
+    <Pressable onPress={onPress} style={{ flex: 1 }}>
+      <XStack
+        alignItems="center"
+        justifyContent="center"
+        paddingVertical="$2"
+        borderRadius={10}
+        backgroundColor={active ? backdrop : surfaceMuted}
+        borderWidth={1}
+        borderColor={active ? backdrop : border}
+      >
+        <Text fontSize="$xs" color={active ? surface : backdrop} fontWeight="700">
+          {label}
+        </Text>
+      </XStack>
+    </Pressable>
+  );
+}
diff --git a/resources/js/guest/context/EventBrandingContext.tsx b/resources/js/guest/context/EventBrandingContext.tsx
index 30c374a..5b82eb2 100644
--- a/resources/js/guest/context/EventBrandingContext.tsx
+++ b/resources/js/guest/context/EventBrandingContext.tsx
@@ -160,48 +160,32 @@ function applyThemeMode(mode: EventBranding['mode']) {
   }
 
   const root = document.documentElement;
-  const prefersDark = typeof window !== 'undefined'
+  const prefersDark = typeof window !== 'undefined' && typeof window.matchMedia === 'function'
     ? window.matchMedia('(prefers-color-scheme: dark)').matches
     : false;
-
-  let storedTheme: 'light' | 'dark' | 'system' | null = null;
-
-  try {
-    const raw = localStorage.getItem('theme');
-    storedTheme = raw === 'light' || raw === 'dark' || raw === 'system' ? raw : null;
-  } catch {
-    storedTheme = null;
-  }
-
   const applyDark = () => root.classList.add('dark');
   const applyLight = () => root.classList.remove('dark');
 
   if (mode === 'dark') {
     applyDark();
+    root.style.colorScheme = 'dark';
     return;
   }
 
   if (mode === 'light') {
     applyLight();
-    return;
-  }
-
-  if (storedTheme === 'dark') {
-    applyDark();
-    return;
-  }
-
-  if (storedTheme === 'light') {
-    applyLight();
+    root.style.colorScheme = 'light';
     return;
   }
 
   if (prefersDark) {
     applyDark();
+    root.style.colorScheme = 'dark';
     return;
   }
 
   applyLight();
+  root.style.colorScheme = 'light';
 }
 
 export function EventBrandingProvider({
@@ -214,6 +198,9 @@ export function EventBrandingProvider({
   const resolved = useMemo(() => resolveBranding(branding), [branding]);
 
   useEffect(() => {
+    if (typeof document !== 'undefined') {
+      document.documentElement.classList.add('guest-theme');
+    }
     applyCssVariables(resolved);
     const previousDark = typeof document !== 'undefined' ? document.documentElement.classList.contains('dark') : false;
     applyThemeMode(resolved.mode ?? 'auto');
@@ -225,6 +212,7 @@ export function EventBrandingProvider({
         } else {
           document.documentElement.classList.remove('dark');
         }
+        document.documentElement.classList.remove('guest-theme');
       }
       resetCssVariables();
       applyCssVariables(DEFAULT_EVENT_BRANDING);
diff --git a/resources/js/guest/context/__tests__/EventBrandingContext.test.tsx b/resources/js/guest/context/__tests__/EventBrandingContext.test.tsx
new file mode 100644
index 0000000..17be86c
--- /dev/null
+++ b/resources/js/guest/context/__tests__/EventBrandingContext.test.tsx
@@ -0,0 +1,40 @@
+import React from 'react';
+import { render, waitFor } from '@testing-library/react';
+import { EventBrandingProvider } from '../EventBrandingContext';
+import type { EventBranding } from '../../types/event-branding';
+
+const sampleBranding: EventBranding = {
+  primaryColor: '#ff3366',
+  secondaryColor: '#ff99aa',
+  backgroundColor: '#fef2f2',
+  fontFamily: 'Montserrat, sans-serif',
+  logoUrl: null,
+  mode: 'dark',
+};
+
+describe('EventBrandingProvider', () => {
+  afterEach(() => {
+    document.documentElement.classList.remove('guest-theme', 'dark');
+    document.documentElement.style.removeProperty('color-scheme');
+    document.documentElement.style.removeProperty('--guest-background');
+  });
+
+  it('applies guest theme classes and variables', async () => {
+    const { unmount } = render(
+      <EventBrandingProvider branding={sampleBranding}>
+        <div>Guest</div>
+      </EventBrandingProvider>
+    );
+
+    await waitFor(() => {
+      expect(document.documentElement.classList.contains('guest-theme')).toBe(true);
+      expect(document.documentElement.classList.contains('dark')).toBe(true);
+      expect(document.documentElement.style.colorScheme).toBe('dark');
+      expect(document.documentElement.style.getPropertyValue('--guest-background')).toBe(sampleBranding.backgroundColor);
+    });
+
+    unmount();
+
+    expect(document.documentElement.classList.contains('guest-theme')).toBe(false);
+  });
+});
diff --git a/resources/js/guest/lib/__tests__/guestTheme.test.ts b/resources/js/guest/lib/__tests__/guestTheme.test.ts
new file mode 100644
index 0000000..9e70d8a
--- /dev/null
+++ b/resources/js/guest/lib/__tests__/guestTheme.test.ts
@@ -0,0 +1,35 @@
+import { describe, expect, it, afterEach } from 'vitest';
+import { applyGuestTheme } from '../guestTheme';
+
+const baseTheme = {
+  primary: '#ff3366',
+  secondary: '#ff99aa',
+  background: '#111111',
+  surface: '#222222',
+  mode: 'dark' as const,
+};
+
+describe('applyGuestTheme', () => {
+  afterEach(() => {
+    const root = document.documentElement;
+    root.classList.remove('guest-theme', 'dark');
+    root.style.removeProperty('color-scheme');
+    root.style.removeProperty('--guest-primary');
+    root.style.removeProperty('--guest-secondary');
+    root.style.removeProperty('--guest-background');
+    root.style.removeProperty('--guest-surface');
+  });
+
+  it('applies and restores guest theme settings', () => {
+    const cleanup = applyGuestTheme(baseTheme);
+
+    expect(document.documentElement.classList.contains('guest-theme')).toBe(true);
+    expect(document.documentElement.classList.contains('dark')).toBe(true);
+    expect(document.documentElement.style.colorScheme).toBe('dark');
+    expect(document.documentElement.style.getPropertyValue('--guest-background')).toBe('#111111');
+
+    cleanup();
+
+    expect(document.documentElement.classList.contains('guest-theme')).toBe(false);
+  });
+});
diff --git a/resources/js/guest/lib/guestTheme.ts b/resources/js/guest/lib/guestTheme.ts
new file mode 100644
index 0000000..9541a8a
--- /dev/null
+++ b/resources/js/guest/lib/guestTheme.ts
@@ -0,0 +1,103 @@
+export type GuestThemePayload = {
+  primary: string;
+  secondary: string;
+  background: string;
+  surface: string;
+  mode?: 'light' | 'dark' | 'auto';
+};
+
+type GuestThemeCleanup = () => void;
+
+const prefersDarkScheme = (): boolean => {
+  if (typeof window === 'undefined' || typeof window.matchMedia !== 'function') {
+    return false;
+  }
+
+  return window.matchMedia('(prefers-color-scheme: dark)').matches;
+};
+
+const applyColorScheme = (root: HTMLElement, theme: 'light' | 'dark') => {
+  if (theme === 'dark') {
+    root.classList.add('dark');
+    root.style.colorScheme = 'dark';
+  } else {
+    root.classList.remove('dark');
+    root.style.colorScheme = 'light';
+  }
+};
+
+export function applyGuestTheme(payload: GuestThemePayload): GuestThemeCleanup {
+  if (typeof document === 'undefined') {
+    return () => {};
+  }
+
+  const root = document.documentElement;
+  const hadGuestTheme = root.classList.contains('guest-theme');
+  const wasDark = root.classList.contains('dark');
+  const previousColorScheme = root.style.colorScheme;
+  const previousVars = {
+    primary: root.style.getPropertyValue('--guest-primary'),
+    secondary: root.style.getPropertyValue('--guest-secondary'),
+    background: root.style.getPropertyValue('--guest-background'),
+    surface: root.style.getPropertyValue('--guest-surface'),
+  };
+
+  root.classList.add('guest-theme');
+  root.style.setProperty('--guest-primary', payload.primary);
+  root.style.setProperty('--guest-secondary', payload.secondary);
+  root.style.setProperty('--guest-background', payload.background);
+  root.style.setProperty('--guest-surface', payload.surface);
+
+  const mode = payload.mode ?? 'auto';
+  if (mode === 'dark') {
+    applyColorScheme(root, 'dark');
+  } else if (mode === 'light') {
+    applyColorScheme(root, 'light');
+  } else {
+    applyColorScheme(root, prefersDarkScheme() ? 'dark' : 'light');
+  }
+
+  return () => {
+    if (hadGuestTheme) {
+      root.classList.add('guest-theme');
+    } else {
+      root.classList.remove('guest-theme');
+    }
+
+    if (wasDark) {
+      root.classList.add('dark');
+    } else {
+      root.classList.remove('dark');
+    }
+
+    if (previousColorScheme) {
+      root.style.colorScheme = previousColorScheme;
+    } else {
+      root.style.removeProperty('color-scheme');
+    }
+
+    if (previousVars.primary) {
+      root.style.setProperty('--guest-primary', previousVars.primary);
+    } else {
+      root.style.removeProperty('--guest-primary');
+    }
+
+    if (previousVars.secondary) {
+      root.style.setProperty('--guest-secondary', previousVars.secondary);
+    } else {
+      root.style.removeProperty('--guest-secondary');
+    }
+
+    if (previousVars.background) {
+      root.style.setProperty('--guest-background', previousVars.background);
+    } else {
+      root.style.removeProperty('--guest-background');
+    }
+
+    if (previousVars.surface) {
+      root.style.setProperty('--guest-surface', previousVars.surface);
+    } else {
+      root.style.removeProperty('--guest-surface');
+    }
+  };
+}
diff --git a/resources/js/guest/main.tsx b/resources/js/guest/main.tsx
index dda82c0..5efe91e 100644
--- a/resources/js/guest/main.tsx
+++ b/resources/js/guest/main.tsx
@@ -1,7 +1,6 @@
 import React, { Suspense } from 'react';
 import { createRoot } from 'react-dom/client';
 import '../../css/app.css';
-import { AppearanceProvider, initializeTheme } from '@/hooks/use-appearance';
 import { enableGuestDemoMode, shouldEnableGuestDemoMode } from './demo/demoMode';
 import { Sentry, initSentry } from '@/lib/sentry';
 
@@ -11,7 +10,6 @@ const GuestFallback: React.FC<{ message: string }> = ({ message }) => (
   </div>
 );
 
-initializeTheme();
 initSentry('guest');
 if (shouldEnableGuestDemoMode()) {
   enableGuestDemoMode();
@@ -24,9 +22,7 @@ const shareRoot = async () => {
   createRoot(rootEl).render(
     <Sentry.ErrorBoundary fallback={<GuestFallback message="Dieses Foto kann gerade nicht geladen werden." />}>
       <React.StrictMode>
-        <AppearanceProvider>
-          <SharedPhotoStandalone />
-        </AppearanceProvider>
+        <SharedPhotoStandalone />
       </React.StrictMode>
     </Sentry.ErrorBoundary>
   );
@@ -51,17 +47,15 @@ const appRoot = async () => {
   createRoot(rootEl).render(
     <Sentry.ErrorBoundary fallback={<GuestFallback message="Erlebnisse können nicht geladen werden." />}>
       <React.StrictMode>
-        <AppearanceProvider>
-          <LocaleProvider>
-            <ToastProvider>
-              <MatomoTracker config={matomoConfig} />
-              <PwaManager />
-              <Suspense fallback={<GuestFallback message="Erlebnisse werden geladen …" />}>
-                <RouterProvider router={router} />
-              </Suspense>
-            </ToastProvider>
-          </LocaleProvider>
-        </AppearanceProvider>
+        <LocaleProvider>
+          <ToastProvider>
+            <MatomoTracker config={matomoConfig} />
+            <PwaManager />
+            <Suspense fallback={<GuestFallback message="Erlebnisse werden geladen …" />}>
+              <RouterProvider router={router} />
+            </Suspense>
+          </ToastProvider>
+        </LocaleProvider>
       </React.StrictMode>
     </Sentry.ErrorBoundary>
   );
diff --git a/resources/js/guest/pages/PublicGalleryPage.tsx b/resources/js/guest/pages/PublicGalleryPage.tsx
index bcea209..17e0890 100644
--- a/resources/js/guest/pages/PublicGalleryPage.tsx
+++ b/resources/js/guest/pages/PublicGalleryPage.tsx
@@ -9,9 +9,8 @@ import { useTranslation } from '../i18n/useTranslation';
 import { DEFAULT_LOCALE, isLocaleCode } from '../i18n/messages';
 import { AlertTriangle, Download, Loader2, Share, X } from 'lucide-react';
 import { createPhotoShareLink } from '../services/photosApi';
-import { Share } from 'lucide-react';
-import { createPhotoShareLink } from '../services/photosApi';
 import { getContrastingTextColor } from '../lib/color';
+import { applyGuestTheme } from '../lib/guestTheme';
 
 interface GalleryState {
   meta: GalleryMetaResponse | null;
@@ -95,28 +94,34 @@ export default function PublicGalleryPage(): React.ReactElement | null {
     loadInitial();
   }, [loadInitial]);
 
+  const resolvedBranding = useMemo(() => {
+    if (!state.meta) {
+      return null;
+    }
+
+    const palette = state.meta.branding.palette ?? {};
+    const primary = palette.primary ?? state.meta.branding.primary_color ?? '#f43f5e';
+    const secondary = palette.secondary ?? state.meta.branding.secondary_color ?? '#fb7185';
+    const background = palette.background ?? state.meta.branding.background_color ?? '#ffffff';
+    const surface = palette.surface ?? state.meta.branding.surface_color ?? background;
+    const mode = state.meta.branding.mode ?? 'auto';
+
+    return {
+      primary,
+      secondary,
+      background,
+      surface,
+      mode,
+    };
+  }, [state.meta]);
+
   useEffect(() => {
-    const mode = state.meta?.branding.mode;
-    if (!mode || typeof document === 'undefined') {
+    if (!resolvedBranding) {
       return;
     }
 
-    const wasDark = document.documentElement.classList.contains('dark');
-
-    if (mode === 'dark') {
-      document.documentElement.classList.add('dark');
-    } else if (mode === 'light') {
-      document.documentElement.classList.remove('dark');
-    }
-
-    return () => {
-      if (wasDark) {
-        document.documentElement.classList.add('dark');
-      } else {
-        document.documentElement.classList.remove('dark');
-      }
-    };
-  }, [state.meta?.branding.mode]);
+    return applyGuestTheme(resolvedBranding);
+  }, [resolvedBranding]);
 
   const loadMore = useCallback(async () => {
     if (!token || !state.cursor || state.loadingMore) {
@@ -164,55 +169,46 @@ export default function PublicGalleryPage(): React.ReactElement | null {
   }, [state.cursor, loadMore]);
 
   const themeStyles = useMemo(() => {
-    if (!state.meta) {
+    if (!resolvedBranding) {
       return {} as React.CSSProperties;
     }
 
-    const palette = state.meta.branding.palette ?? {};
-    const primary = palette.primary ?? state.meta.branding.primary_color;
-    const secondary = palette.secondary ?? state.meta.branding.secondary_color;
-    const background = palette.background ?? state.meta.branding.background_color;
-    const surface = palette.surface ?? state.meta.branding.surface_color ?? background;
-
     return {
-      '--gallery-primary': primary,
-      '--gallery-secondary': secondary,
-      '--gallery-background': background,
-      '--gallery-surface': surface,
+      '--gallery-primary': resolvedBranding.primary,
+      '--gallery-secondary': resolvedBranding.secondary,
+      '--gallery-background': resolvedBranding.background,
+      '--gallery-surface': resolvedBranding.surface,
     } as React.CSSProperties & Record<string, string>;
-  }, [state.meta]);
+  }, [resolvedBranding]);
 
   const headerStyle = useMemo(() => {
-    if (!state.meta) {
+    if (!resolvedBranding) {
       return {};
     }
-    const palette = state.meta.branding.palette ?? {};
-    const primary = palette.primary ?? state.meta.branding.primary_color;
-    const secondary = palette.secondary ?? state.meta.branding.secondary_color ?? primary;
-    const textColor = getContrastingTextColor(primary ?? '#f43f5e', '#0f172a', '#ffffff');
+    const textColor = getContrastingTextColor(resolvedBranding.primary, '#0f172a', '#ffffff');
     return {
-      background: `linear-gradient(135deg, ${primary}, ${secondary})`,
+      background: `linear-gradient(135deg, ${resolvedBranding.primary}, ${resolvedBranding.secondary})`,
       color: textColor,
     } satisfies React.CSSProperties;
-  }, [state.meta]);
+  }, [resolvedBranding]);
 
   const accentStyle = useMemo(() => {
-    if (!state.meta) {
+    if (!resolvedBranding) {
       return {};
     }
     return {
-      color: (state.meta.branding.palette?.primary ?? state.meta.branding.primary_color),
+      color: resolvedBranding.primary,
     } satisfies React.CSSProperties;
-  }, [state.meta]);
+  }, [resolvedBranding]);
 
   const backgroundStyle = useMemo(() => {
-    if (!state.meta) {
+    if (!resolvedBranding) {
       return {};
     }
     return {
-      backgroundColor: state.meta.branding.palette?.background ?? state.meta.branding.background_color,
+      backgroundColor: resolvedBranding.background,
     } satisfies React.CSSProperties;
-  }, [state.meta]);
+  }, [resolvedBranding]);
 
   const openLightbox = useCallback((photo: GalleryPhotoResource) => {
     setSelectedPhoto(photo);
diff --git a/resources/js/guest/pages/UploadPage.tsx b/resources/js/guest/pages/UploadPage.tsx
index 189d29c..42c5d6e 100644
--- a/resources/js/guest/pages/UploadPage.tsx
+++ b/resources/js/guest/pages/UploadPage.tsx
@@ -1488,7 +1488,7 @@ const renderWithDialog = (content: ReactNode, wrapperClassName = 'space-y-6 pb-[
                   </div>
                 </div>
               ) : (
-                <div className="relative h-24 w-24">
+                <div className="relative flex h-24 w-24 items-center justify-center">
                   {!isCountdownActive && mode !== 'uploading' && (
                     <span className="pointer-events-none absolute inset-0 rounded-full border border-white/30 opacity-60 animate-ping" />
                   )}
diff --git a/resources/js/guest/pages/__tests__/UploadPageImmersive.test.tsx b/resources/js/guest/pages/__tests__/UploadPageImmersive.test.tsx
index b95d981..c2ac109 100644
--- a/resources/js/guest/pages/__tests__/UploadPageImmersive.test.tsx
+++ b/resources/js/guest/pages/__tests__/UploadPageImmersive.test.tsx
@@ -1,6 +1,6 @@
 import React from 'react';
 import { describe, expect, it, vi } from 'vitest';
-import { render, waitFor } from '@testing-library/react';
+import { render, screen, waitFor } from '@testing-library/react';
 import UploadPage from '../UploadPage';
 
 vi.mock('react-router-dom', () => ({
@@ -73,4 +73,15 @@ describe('UploadPage immersive mode', () => {
       expect(document.body.classList.contains('guest-immersive')).toBe(true);
     });
   });
+
+  it('centers the capture button within the countdown ring', () => {
+    render(<UploadPage />);
+
+    const captureButton = screen.getByRole('button', { name: 'upload.buttons.startCamera' });
+    const wrapper = captureButton.parentElement;
+
+    expect(wrapper).not.toBeNull();
+    expect(wrapper?.className).toContain('items-center');
+    expect(wrapper?.className).toContain('justify-center');
+  });
 });