diff --git a/src/frontend/App.tsx b/src/frontend/App.tsx
index 09b029f..838a693 100644
--- a/src/frontend/App.tsx
+++ b/src/frontend/App.tsx
@@ -4,38 +4,38 @@ import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
 import { createRouter, RouterProvider } from '@tanstack/react-router'
 import { routeTree } from './routeTree.gen'
 
-const theme = createTheme({
+  const theme = createTheme({
   primaryColor: 'brand-blue',
   colors: {
     'brand-blue': [
-      '#ebf2ff',
-      '#d6e4ff',
-      '#adc8ff',
-      '#85acff',
-      '#5c90ff',
-      '#2563eb', // Primary Blue
-      '#1e4fb8',
-      '#173b85',
-      '#102752',
-      '#09131f',
+      '#f0f9ff',
+      '#e0f2fe',
+      '#bae6fd',
+      '#7dd3fc',
+      '#38bdf8',
+      '#0ea5e9', // Primary Blue (Sky)
+      '#0284c7',
+      '#0369a1',
+      '#075985',
+      '#0c4a6e',
     ],
     'brand-purple': [
-      '#f3ebff',
-      '#e7d6ff',
-      '#cfadff',
-      '#b785ff',
-      '#9f5cff',
-      '#7c3aed', // Primary Purple
-      '#632eb8',
-      '#4a2285',
-      '#311652',
-      '#180b1f',
+      '#faf5ff',
+      '#f3e8ff',
+      '#e9d5ff',
+      '#d8b4fe',
+      '#c084fc',
+      '#a855f7', // Primary Purple
+      '#9333ea',
+      '#7e22ce',
+      '#6b21a8',
+      '#581c87',
     ],
   },
   fontFamily: 'Inter, system-ui, Avenir, Helvetica, Arial, sans-serif',
   headings: {
     fontFamily: 'Inter, system-ui, sans-serif',
-    fontWeight: '600',
+    fontWeight: '500', // Softer headings
   },
 })
 
@@ -59,8 +59,8 @@ declare module '@tanstack/react-router' {
 export function App() {
   return (
     <>
-      <ColorSchemeScript defaultColorScheme="dark" />
-      <MantineProvider theme={theme} defaultColorScheme="dark" forceColorScheme="dark">
+      <ColorSchemeScript defaultColorScheme="auto" />
+      <MantineProvider theme={theme} defaultColorScheme="auto">
         <QueryClientProvider client={queryClient}>
           <RouterProvider router={router} />
         </QueryClientProvider>
diff --git a/src/frontend/components/AppCard.tsx b/src/frontend/components/AppCard.tsx
index 4880e26..130c03b 100644
--- a/src/frontend/components/AppCard.tsx
+++ b/src/frontend/components/AppCard.tsx
@@ -1,4 +1,4 @@
-import { Card, Group, Text, ThemeIcon, Badge, Avatar, Stack, Button, Progress, Box } from '@mantine/core'
+import { Card, Group, Text, ThemeIcon, Badge, Avatar, Stack, Button, Progress, Box, useComputedColorScheme } from '@mantine/core'
 import { Link } from '@tanstack/react-router'
 import { TbDeviceMobile, TbActivity, TbAlertTriangle, TbChevronRight } from 'react-icons/tb'
 
@@ -13,6 +13,7 @@ interface AppCardProps {
 
 export function AppCard({ id, name, status, users, errors, version }: AppCardProps) {
   const statusColor = status === 'active' ? 'teal' : status === 'warning' ? 'orange' : 'red'
+  const scheme = useComputedColorScheme('light', { getInitialValueInEffect: true })
 
   return (
     <Card
@@ -22,12 +23,12 @@ export function AppCard({ id, name, status, users, errors, version }: AppCardPro
       className="premium-card glass"
       styles={(theme) => ({
         root: {
-          backgroundColor: 'rgba(30, 41, 59, 0.4)',
-          borderColor: 'rgba(255,255,255,0.08)',
-          transition: 'transform 0.2s ease, box-shadow 0.2s ease',
+          backgroundColor: 'var(--mantine-color-body)',
+          borderColor: scheme === 'dark' ? 'rgba(255,255,255,0.08)' : 'rgba(0,0,0,0.05)',
+          transition: 'transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, border-color 0.2s ease',
           '&:hover': {
             transform: 'translateY(-4px)',
-            boxShadow: '0 12px 24px -8px rgba(0, 0, 0, 0.4)',
+            boxShadow: theme.shadows.md,
             borderColor: 'rgba(37, 99, 235, 0.3)',
           },
         },
diff --git a/src/frontend/components/DashboardLayout.tsx b/src/frontend/components/DashboardLayout.tsx
index 1a119e7..133c8ad 100644
--- a/src/frontend/components/DashboardLayout.tsx
+++ b/src/frontend/components/DashboardLayout.tsx
@@ -1,5 +1,6 @@
 import { APP_CONFIGS } from '@/frontend/config/appMenus'
 import {
+  ActionIcon,
   AppShell,
   Avatar,
   Box,
@@ -14,6 +15,7 @@ import {
   ThemeIcon
 } from '@mantine/core'
 import { useDisclosure } from '@mantine/hooks'
+import { useMantineColorScheme, useComputedColorScheme } from '@mantine/core'
 import { Link, useLocation, useMatches, useNavigate, useParams } from '@tanstack/react-router'
 import {
   TbApps,
@@ -23,7 +25,9 @@ import {
   TbDeviceMobile,
   TbLogout,
   TbSettings,
-  TbUserCircle
+  TbUserCircle,
+  TbSun,
+  TbMoon
 } from 'react-icons/tb'
 
 interface DashboardLayoutProps {
@@ -31,7 +35,10 @@ interface DashboardLayoutProps {
 }
 
 export function DashboardLayout({ children }: DashboardLayoutProps) {
-  const [opened, { toggle }] = useDisclosure()
+  const [mobileOpened, { toggle: toggleMobile }] = useDisclosure()
+  const [desktopOpened, { toggle: toggleDesktop }] = useDisclosure(true)
+  const { toggleColorScheme } = useMantineColorScheme()
+  const computedColorScheme = useComputedColorScheme('light', { getInitialValueInEffect: true })
   const location = useLocation()
   const navigate = useNavigate()
   const { appId } = useParams({ strict: false }) as { appId?: string }
@@ -54,19 +61,21 @@ export function DashboardLayout({ children }: DashboardLayoutProps) {
       navbar={{
         width: 260,
         breakpoint: 'sm',
-        collapsed: { mobile: !opened },
+        collapsed: { mobile: !mobileOpened, desktop: !desktopOpened },
       }}
       padding="xl"
       styles={(theme) => ({
         main: {
-          backgroundColor: theme.colors.dark[7], // Dark mode background
+          backgroundColor: computedColorScheme === 'dark' ? theme.colors.dark[9] : theme.colors.gray[0],
+          transition: 'background-color 0.2s ease',
         },
       })}
     >
       <AppShell.Header px="xl">
         <Group h="100%" justify="space-between">
           <Group>
-            <Burger opened={opened} onClick={toggle} hiddenFrom="sm" size="sm" />
+            <Burger opened={mobileOpened} onClick={toggleMobile} hiddenFrom="sm" size="sm" />
+            <Burger opened={desktopOpened} onClick={toggleDesktop} visibleFrom="sm" size="sm" />
             <Group gap="xs">
               <ThemeIcon
                 size={34}
@@ -88,6 +97,14 @@ export function DashboardLayout({ children }: DashboardLayoutProps) {
           </Group>
 
           <Group gap="md">
+            <ActionIcon
+              onClick={() => toggleColorScheme()}
+              variant="default"
+              size="lg"
+              aria-label="Toggle color scheme"
+            >
+              {computedColorScheme === 'dark' ? <TbSun size={18} /> : <TbMoon size={18} />}
+            </ActionIcon>
             <Menu shadow="md" width={200} position="bottom-end">
               <Menu.Target>
                 <Avatar
diff --git a/src/frontend/components/StatsCard.tsx b/src/frontend/components/StatsCard.tsx
index d87b2ee..8525456 100644
--- a/src/frontend/components/StatsCard.tsx
+++ b/src/frontend/components/StatsCard.tsx
@@ -22,8 +22,8 @@ export function StatsCard({ title, value, description, icon: Icon, color, trend
       className="premium-card"
       styles={(theme) => ({
         root: {
-          backgroundColor: theme.colors.dark[6],
-          borderColor: 'rgba(255,255,255,0.05)',
+          backgroundColor: 'var(--mantine-color-body)',
+          borderColor: 'rgba(128,128,128,0.1)',
         },
       })}
     >
diff --git a/src/frontend/components/SummaryCard.tsx b/src/frontend/components/SummaryCard.tsx
index d3c3681..e1238dc 100644
--- a/src/frontend/components/SummaryCard.tsx
+++ b/src/frontend/components/SummaryCard.tsx
@@ -1,4 +1,4 @@
-import { Card, Group, Text, ThemeIcon, Stack, Progress, Badge } from '@mantine/core'
+import { Card, Group, Text, ThemeIcon, Stack, Progress, Badge, useComputedColorScheme } from '@mantine/core'
 import { IconType } from 'react-icons'
 import { TbTrendingUp, TbTrendingDown } from 'react-icons/tb'
 
@@ -27,6 +27,8 @@ export function SummaryCard({
     progress,
     isError 
 }: SummaryCardProps) {
+  const scheme = useComputedColorScheme('light', { getInitialValueInEffect: true })
+
   return (
     <Card
       withBorder
@@ -35,9 +37,13 @@ export function SummaryCard({
       className="glass"
       styles={(theme) => ({
         root: {
-          backgroundColor: isError && Number(value) > 0 ? 'rgba(239, 68, 68, 0.05)' : 'rgba(30, 41, 59, 0.4)',
-          borderColor: isError && Number(value) > 10 ? 'rgba(239, 68, 68, 0.3)' : 'rgba(255, 255, 255, 0.08)',
-          transition: 'transform 0.2s ease',
+          backgroundColor: isError && Number(value) > 0 
+            ? (scheme === 'dark' ? 'rgba(239, 68, 68, 0.1)' : 'rgba(255, 241, 242, 1)') // light pink for error in light mode
+            : 'var(--mantine-color-body)',
+          borderColor: isError && Number(value) > 10 
+            ? 'rgba(239, 68, 68, 0.3)' 
+            : scheme === 'dark' ? 'rgba(255, 255, 255, 0.08)' : 'rgba(0, 0, 0, 0.05)',
+          transition: 'transform 0.2s ease, background-color 0.2s ease, border-color 0.2s ease',
           '&:hover': {
             transform: 'translateY(-4px)',
           }
diff --git a/src/index.css b/src/index.css
index 774be0a..6b5e2f4 100644
--- a/src/index.css
+++ b/src/index.css
@@ -27,8 +27,8 @@ html, body {
   height: 100%;
   width: 100%;
   font-family: var(--font-inter);
-  background-color: var(--bg-dark); /* Default to Dark Mode as per App.tsx */
-  color: #F8FAFC;
+  /* background-color handled by Mantine */
+  color: var(--mantine-color-text);
 }
 
 body {
@@ -53,9 +53,9 @@ body {
 
 /* Premium Dashboard Utilities */
 .glass {
-  background: rgba(30, 41, 59, 0.7);
+  background: var(--mantine-color-default);
   backdrop-filter: blur(12px);
-  border: 1px solid rgba(255, 255, 255, 0.1);
+  border: 1px solid rgba(128, 128, 128, 0.1);
   border-radius: 24px; /* XL rounding for cards */
   box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
 }