feat: Implement core application layout, global styling, dark mode, and essential UI components.

Frontend-Learner/assets/css/main.css

@@ -7,8 +7,8 @@
    =========================== */
 :root {
   /* Colors - Light Mode Default */
-  --bg-body: #f8fafc; /* Light Background */
+  --bg-body: #f8fafc;
-  --bg-surface: #ffffff; /* White Card Background */
+  --bg-surface: #ffffff;
   --text-main: #0f172a; /* Dark Text */
   --text-secondary: #64748b; /* Secondary Text */
   --primary: #3b82f6; /* Primary Blue */
@@ -60,9 +60,9 @@
 .dark {
   --bg-body: #0f172a;
   --bg-surface: #1e293b; /* User requested specific color */
-  --text-main: #f1f5f9;
+  --text-main: #f8fafc; /* text-slate-50: Brighter white for main text */
-  --text-secondary: #cbd5e1;
+  --text-secondary: #cbd5e1; /* text-slate-300: Lighter grey for secondary text */
-  --border-color: #334155;
+  --border-color: #334155; /* border-slate-700: Higher contrast border */
   --neutral-50: #1e293b;
   --neutral-100: #334155;
   --neutral-200: #475569;

Frontend-Learner/components/common/AppHeader.vue

@@ -19,7 +19,7 @@ const searchText = ref('')
 </script>
 
 <template>
-  <q-toolbar class="bg-white text-slate-800 border-b border-gray-100 h-16 px-4">
+  <q-toolbar class="bg-transparent text-slate-800 dark:text-white h-16 px-4">
     <!-- Mobile Menu Toggle -->
     <q-btn
       flat
@@ -27,7 +27,7 @@ const searchText = ref('')
       dense
       icon="menu"
       @click="emit('toggleSidebar')"
-      class="md:hidden mr-2"
+      class="md:hidden mr-2 text-slate-700 dark:text-white"
       aria-label="Menu"
     />
 
@@ -36,7 +36,7 @@ const searchText = ref('')
       <div class="w-8 h-8 rounded-lg bg-blue-600 flex items-center justify-center text-white font-bold">
         E
       </div>
-      <span class="font-bold text-xl text-blue-600 hidden xs:block">e-Learning</span>
+      <span class="font-bold text-xl text-blue-600 dark:text-blue-400 hidden xs:block">e-Learning</span>
     </div>
     
     <q-space />
@@ -49,8 +49,8 @@ const searchText = ref('')
         rounded
         v-model="searchText"
         :placeholder="$t('menu.searchCourses')"
-        class="bg-slate-50 search-input"
+        class="bg-slate-50 dark:bg-slate-700/50 search-input"
-        bg-color="slate-50" 
+        bg-color="transparent" 
       >
         <template v-slot:prepend>
           <q-icon name="search" class="text-slate-400" />

Frontend-Learner/components/common/AppSidebar.vue

@@ -42,10 +42,10 @@ const navItems = computed(() => [
 </script>
 
 <template>
-  <div class="flex flex-col h-full bg-white">
+  <div class="flex flex-col h-full bg-transparent">
     <!-- Branding Area (Optional if not in Header) -->
     
-    <q-list padding class="text-slate-600 flex-grow">
+    <q-list padding class="text-slate-600 dark:text-slate-300 flex-grow">
 
       
       <q-item 
@@ -54,8 +54,7 @@ const navItems = computed(() => [
         :to="item.to"
         clickable 
         v-ripple
-        active-class="text-primary bg-blue-50 font-bold"
+        class="rounded-r-full mr-2 text-slate-700 dark:text-slate-200 hover:bg-slate-100 dark:hover:bg-white/5"
-        class="rounded-r-full mr-2"
       >
         <q-item-section avatar>
           <q-icon :name="item.icon" />
@@ -75,6 +74,17 @@ const navItems = computed(() => [
   </div>
 </template>
 
-<style scoped>
+<style>
-/* Custom styles if needed */
+/* Light Mode Active State */
+.q-item.q-router-link--active {
+  background: rgb(239 246 255); /* blue-50 */
+  color: rgb(29 78 216);       /* blue-700 */
+  font-weight: 700;
+}
+
+/* Dark Mode Active State */
+.dark .q-item.q-router-link--active {
+  background: rgba(255, 255, 255, 0.1);
+  color: rgb(147 197 253);     /* blue-300 */
+}
 </style>

Frontend-Learner/components/user/UserMenu.vue

@@ -4,29 +4,44 @@
  * @description User profile dropdown menu component using Quasar.
  */
 
-import { ref, computed, onMounted, watch } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import { useAuth } from '~/composables/useAuth'
+import { useQuasar } from 'quasar'
 
 const { currentUser, logout } = useAuth()
 const { t } = useI18n()
+const $q = useQuasar()
+
 const isDarkMode = ref(false)
+const isHydrated = ref(false)
 
-// Sync Dark Mode state
+const applyTheme = (value: boolean) => {
+  // Tailwind dark mode
+  document.documentElement.classList.toggle('dark', value)
+
+  // Quasar dark mode
+  $q.dark.set(value)
+
+  // persist
+  localStorage.setItem('theme', value ? 'dark' : 'light')
+}
+
+const toggleDarkMode = (val: boolean) => {
+  isDarkMode.value = val
+  applyTheme(val)
+}
+
+// Sync Dark Mode state on mount
 onMounted(() => {
-  if (document.documentElement.classList.contains('dark')) {
+  isHydrated.value = true
-    isDarkMode.value = true
+  const savedTheme = localStorage.getItem('theme')
-  }
+  const preferredDark = window.matchMedia?.('(prefers-color-scheme: dark)')?.matches ?? false
-})
 
-// Watch for dark mode changes
+  isDarkMode.value = savedTheme
-watch(isDarkMode, (val) => {
+    ? savedTheme === 'dark'
-  if (val) {
+    : preferredDark
-    document.documentElement.classList.add('dark')
+
-    localStorage.setItem('theme', 'dark')
+  applyTheme(isDarkMode.value)
-  } else {
-    document.documentElement.classList.remove('dark')
-    localStorage.setItem('theme', 'light')
-  }
 })
 
 // User Initials
@@ -37,11 +52,6 @@ const userInitials = computed(() => {
   return f + l
 })
 
-const userName = computed(() => {
-  if (!currentUser.value) return 'User'
-  return `${currentUser.value.firstName} ${currentUser.value.lastName}`
-})
-
 const menuItems = computed(() => [
   { label: t('userMenu.home'), to: '/dashboard' },
   { label: t('userMenu.courseList'), to: '/browse/discovery' },
@@ -64,42 +74,40 @@ const handleLogout = async () => {
       <q-menu 
         anchor="bottom end" 
         self="top end" 
-        class="rounded-2xl shadow-xl overflow-hidden border border-slate-100 dark:border-slate-700" 
         :offset="[0, 10]"
-        style="min-width: 240px; background-color: var(--bg-surface);"
+        content-class="bg-white dark:bg-slate-800 text-slate-900 dark:text-white rounded-2xl shadow-xl border border-slate-200/70 dark:border-white/10"
+        style="min-width: 240px;"
       >
-        <div class="bg-[#1e293b] text-white"> 
+        <q-list class="py-2">
-           <!-- Optional header if needed, but per design keeping it simple list -->
-        </div>
-
-        <q-list class="bg-[#1e293b] text-white py-2">
           <q-item 
             v-for="item in menuItems" 
             :key="item.label" 
             clickable 
             v-close-popup 
             @click="navigateTo(item.to)"
-            class="hover:bg-white/10 transition-colors"
+            class="hover:bg-slate-100 dark:hover:bg-white/10 transition-colors"
           >
             <q-item-section>
               <q-item-label class="font-bold text-sm">{{ item.label }}</q-item-label>
             </q-item-section>
           </q-item>
 
-          <q-item class="hover:bg-white/10 transition-colors">
+          <q-item class="hover:bg-slate-100 dark:hover:bg-white/10 transition-colors">
             <q-item-section>
               <q-item-label class="font-bold text-sm">{{ $t('userMenu.darkMode') }}</q-item-label>
             </q-item-section>
             <q-item-section side>
               <q-toggle
-                v-model="isDarkMode"
+                v-if="isHydrated"
+                :model-value="isDarkMode"
+                @update:model-value="toggleDarkMode"
                 color="blue"
                 keep-color
               />
             </q-item-section>
           </q-item>
 
-          <q-separator class="bg-white/10 my-1" />
+          <q-separator class="bg-slate-100 dark:bg-white/10 my-1" />
 
           <div class="p-4">
             <q-btn 
@@ -116,7 +124,3 @@ const handleLogout = async () => {
     </q-btn>
   </div>
 </template>
-
-<style scoped>
-/* Override Quasar generic styles if necessary */
-</style>

Frontend-Learner/layouts/default.vue

@@ -13,9 +13,12 @@ const toggleLeftDrawer = () => {
 </script>
 
 <template>
-  <q-layout view="hHh lpr lFf" class="bg-slate-50 font-inter">
+  <q-layout view="hHh lpr lFf" class="!bg-slate-50 dark:!bg-[#0f172a] !text-slate-900 dark:!text-white font-sans">
     <!-- Header -->
-    <q-header bordered class="bg-white text-slate-800">
+    <q-header
+      bordered
+      class="!bg-white dark:!bg-[#1e293b] !text-slate-900 dark:!text-white border-b border-slate-200 dark:border-slate-700"
+    >
       <AppHeader @toggle-sidebar="toggleLeftDrawer" />
     </q-header>
 
@@ -23,7 +26,7 @@ const toggleLeftDrawer = () => {
     <q-drawer
       v-model="leftDrawerOpen"
       bordered
-      class="bg-white"
+      class="!bg-white dark:!bg-[#1e293b] !text-slate-900 dark:!text-white border-r border-slate-200 dark:border-slate-700"
       :width="260"
     >
       <AppSidebar />
@@ -37,7 +40,11 @@ const toggleLeftDrawer = () => {
     </q-page-container>
 
     <!-- Mobile Bottom Nav -->
-    <q-footer v-if="$q.screen.lt.md" bordered class="bg-white text-primary">
+    <q-footer
+      v-if="$q.screen.lt.md"
+      bordered
+      class="!bg-white dark:!bg-[#1e293b] text-primary border-t border-slate-200 dark:border-slate-700"
+    >
        <MobileNav />
     </q-footer>
   </q-layout>

Frontend-Learner/plugins/theme.client.ts

@@ -0,0 +1,10 @@
+export default defineNuxtPlugin(() => {
+  // Client-side only theme initialization to prevent flash of wrong theme
+  if (process.client) {
+    const saved = localStorage.getItem('theme')
+    const isDark = saved === 'dark' || (!saved && window.matchMedia('(prefers-color-scheme: dark)').matches)
+    
+    // Apply class immediately for Tailwind
+    document.documentElement.classList.toggle('dark', isDark)
+  }
+})

Frontend-Learner/tailwind.config.ts

@@ -27,18 +27,7 @@ export default {
         }
       },
       fontFamily: {
-        sans: [
+        sans: ['var(--font-main)'],
-          'Prompt', 
-          'Sarabun', 
-          'Inter', 
-          '-apple-system', 
-          'BlinkMacSystemFont', 
-          'Segoe UI', 
-          'Roboto', 
-          'Helvetica Neue', 
-          'Arial', 
-          'sans-serif'
-        ],
       }
     }
   },