diff --git a/frontend_management/components/course/LessonPreviewDialog.vue b/frontend_management/components/course/LessonPreviewDialog.vue
index 2d414994..91a4c598 100644
--- a/frontend_management/components/course/LessonPreviewDialog.vue
+++ b/frontend_management/components/course/LessonPreviewDialog.vue
@@ -18,7 +18,16 @@
         <div v-else-if="lessonDetail" class="p-6 space-y-6">
           <!-- Video Player -->
           <div v-if="lesson.type === 'VIDEO' && lessonDetail.video_url" class="aspect-video bg-black rounded-lg overflow-hidden">
+            <iframe
+              v-if="isYoutubeUrl(lessonDetail.video_url)"
+              :src="getYoutubeEmbedUrl(lessonDetail.video_url)"
+              class="w-full h-full"
+              frameborder="0"
+              allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
+              allowfullscreen
+            ></iframe>
             <video
+              v-else
               :src="lessonDetail.video_url"
               controls
               class="w-full h-full object-contain"
@@ -38,7 +47,7 @@
             </h3>
             <div class="grid grid-cols-1 md:grid-cols-2 gap-3">
               <a
-                v-for="file in lessonDetail.attachments"
+                v-for="file in lessonDetail.attachments.filter(f => !['video/mp4', 'video/youtube'].includes(f.mime_type))"
                 :key="file.id"
                 :href="file.file_path"
                 target="_blank"
@@ -175,6 +184,23 @@ const formatFileSize = (bytes: number) => {
   return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
 };
 
+const isYoutubeUrl = (url: string) => {
+  return url.includes('youtube.com') || url.includes('youtu.be');
+};
+
+const getYoutubeEmbedUrl = (url: string) => {
+  let videoId = '';
+  
+  if (url.includes('youtu.be')) {
+    videoId = url.split('/').pop()?.split('?')[0] || '';
+  } else if (url.includes('youtube.com')) {
+    const params = new URLSearchParams(url.split('?')[1]);
+    videoId = params.get('v') || '';
+  }
+
+  return `https://www.youtube.com/embed/${videoId}`;
+};
+
 const fetchLessonDetail = async () => {
   // Always verify lesson and courseId exist
   if (!props.lesson || !props.courseId) return;
diff --git a/frontend_management/pages/admin/courses/[id].vue b/frontend_management/pages/admin/courses/[id].vue
index 1dd1ac68..8cc77977 100644
--- a/frontend_management/pages/admin/courses/[id].vue
+++ b/frontend_management/pages/admin/courses/[id].vue
@@ -212,12 +212,16 @@
             กรุณาระบุเหตุผลในการปฏิเสธคอร์ส "{{ course?.title.th }}"
           </p>
           <q-input
+            ref="rejectInputRef"
             v-model="rejectReason"
             type="textarea"
             outlined
             rows="4"
             label="เหตุผล *"
-            :rules="[val => !!val || 'กรุณาระบุเหตุผล']"
+            :rules="[
+              val => !!val || 'กรุณาระบุเหตุผล',
+              val => (val && val.length >= 10) || 'ระบุเหตุผลอย่างน้อย 10 ตัวอักษร'
+            ]"
             hide-bottom-space
             lazy-rules="ondemand"
           />
@@ -229,7 +233,6 @@
             label="ยืนยันการปฏิเสธ"
             color="negative"
             :loading="actionLoading"
-            :disable="!rejectReason.trim()"
             @click="confirmReject"
           />
         </q-card-actions>
@@ -239,7 +242,7 @@
 </template>
 
 <script setup lang="ts">
-import { useQuasar } from 'quasar';
+import { useQuasar, QInput } from 'quasar';
 import { adminService, type CourseDetailForReview } from '~/services/admin.service';
 
 definePageMeta({
@@ -258,6 +261,7 @@ const error = ref('');
 const actionLoading = ref(false);
 const showRejectModal = ref(false);
 const rejectReason = ref('');
+const rejectInputRef = ref<QInput | null>(null);
 
 // Computed
 const totalLessons = computed(() => 
@@ -415,7 +419,8 @@ const confirmApprove = () => {
 };
 
 const confirmReject = async () => {
-  if (!course.value || !rejectReason.value.trim()) return;
+  rejectInputRef.value?.validate();
+  if (rejectInputRef.value?.hasError || !course.value) return;
   
   actionLoading.value = true;
   try {
diff --git a/frontend_management/pages/admin/courses/pending.vue b/frontend_management/pages/admin/courses/pending.vue
index c9503538..800855c8 100644
--- a/frontend_management/pages/admin/courses/pending.vue
+++ b/frontend_management/pages/admin/courses/pending.vue
@@ -215,7 +215,7 @@
 </template>
 
 <script setup lang="ts">
-import { useQuasar } from 'quasar';
+import { useQuasar, type QTableColumn } from 'quasar';
 import { adminService, type PendingCourse } from '~/services/admin.service';
 
 definePageMeta({
@@ -232,12 +232,12 @@ const loading = ref(true);
 const searchQuery = ref('');
 const viewMode = ref('table');
 
-const columns = [
+const columns: QTableColumn[] = [
   { name: 'thumbnail', label: 'รูปปก', field: 'thumbnail', align: 'left' },
-  { name: 'title', label: 'ชื่อคอร์ส', field: (row: PendingCourse) => row.title.th, align: 'left', sortable: true },
-  { name: 'instructor', label: 'ผู้สอน', field: (row: PendingCourse) => getPrimaryInstructor(row), align: 'left', sortable: true },
+  { name: 'title', label: 'ชื่อคอร์ส', field: (row: any) => row.title.th, align: 'left', sortable: true },
+  { name: 'instructor', label: 'ผู้สอน', field: (row: any) => getPrimaryInstructor(row), align: 'left', sortable: true },
   { name: 'stats', label: 'จำนวนบท', field: 'stats', align: 'center' },
-  { name: 'submitted_at', label: 'วันที่ส่ง', field: (row: PendingCourse) => row.latest_submission?.created_at, align: 'left', sortable: true },
+  { name: 'submitted_at', label: 'วันที่ส่ง', field: (row: any) => row.latest_submission?.created_at, align: 'left', sortable: true },
   { name: 'actions', label: '', field: 'actions', align: 'center' }
 ];
 
diff --git a/frontend_management/pages/admin/recommended-courses/index.vue b/frontend_management/pages/admin/recommended-courses/index.vue
index 8eeef6fb..b4c8cb48 100644
--- a/frontend_management/pages/admin/recommended-courses/index.vue
+++ b/frontend_management/pages/admin/recommended-courses/index.vue
@@ -104,7 +104,7 @@
        <!-- View Details Dialog -->
       <q-dialog v-model="showDialog" maximized transition-show="slide-up" transition-hide="slide-down">
         <q-card>
-          <q-bar class="bg-primary text-white">
+          <q-bar class="bg-primary-500 text-white">
             <q-space />
             <q-btn dense flat icon="close" v-close-popup>
               <q-tooltip class="bg-white text-primary">Close</q-tooltip>
@@ -153,7 +153,7 @@
                    <!-- Category -->
                    <div class="bg-gray-50 p-4 rounded-lg gap-2">
                       <div class="font-bold mb-2">หมวดหมู่ (Category):</div>
-                      <div class="mb-2">{{ selectedCourse.category.name.th }} ({{ selectedCourse.category.name.en }})</div>
+                      <div class="text-gray-700 mb-2">{{ selectedCourse.category.name.th }} ({{ selectedCourse.category.name.en }})</div>
                    </div>
 
                    <!-- Instructors -->
@@ -164,7 +164,7 @@
                              <q-icon name="person" />
                          </q-avatar>
                          <div>
-                            <div class="font-medium">{{ inst.user.username }}</div>
+                            <div class="font-medium text-gray-700">{{ inst.user.username }}</div>
                             <div class="text-xs text-gray-500" v-if="inst.is_primary">(Primary)</div>
                          </div>
                       </div>
@@ -237,7 +237,7 @@ const columns = [
   { name: 'category', label: 'Category', field: (row: RecommendedCourse) => row.category.name.th, sortable: true, align: 'left' as const },
   { name: 'price', label: 'Price', field: 'price', sortable: true, align: 'right' as const },
   { name: 'is_recommended', label: 'Recommended', field: 'is_recommended', sortable: true, align: 'center' as const },
-  //{ name: 'actions', label: 'Actions', field: 'actions', align: 'center' as const },
+  { name: 'actions', label: 'Actions', field: 'actions', align: 'center' as const },
 ];
 
 const fetchCourses = async () => {
@@ -248,7 +248,8 @@ const fetchCourses = async () => {
     console.error('Error fetching courses:', error);
     $q.notify({
       type: 'negative',
-      message: 'ไม่สามารถโหลดข้อมูลคอร์สได้'
+      message: 'ไม่สามารถโหลดข้อมูลคอร์สได้',
+      position: 'top'
     });
   } finally {
     loading.value = false;
@@ -265,7 +266,8 @@ const viewCourse = async (id: number) => {
       console.error('Error fetching course details:', error);
       $q.notify({
          type: 'negative',
-         message: 'ไม่สามารถโหลดข้อมูลรายละเอียดคอร์สได้'
+         message: 'ไม่สามารถโหลดข้อมูลรายละเอียดคอร์สได้',
+         position: 'top'
       });
       showDialog.value = false;
    } finally {
@@ -278,7 +280,8 @@ const handleToggleRecommendation = async (course: RecommendedCourse, isRecommend
     await adminService.toggleCourseRecommendation(course.id, isRecommended);
     $q.notify({
       type: 'positive',
-      message: isRecommended ? 'เพิ่มคอร์สแนะนำสำร็จ' : 'ยกเลิกคอร์สแนะนำสำเร็จ'
+      message: isRecommended ? 'เพิ่มคอร์สแนะนำสำร็จ' : 'ยกเลิกคอร์สแนะนำสำเร็จ',
+      position: 'top'
     });
   } catch (error) {
     console.error('Error toggling recommendation:', error);
@@ -286,7 +289,8 @@ const handleToggleRecommendation = async (course: RecommendedCourse, isRecommend
     course.is_recommended = !isRecommended;
     $q.notify({
       type: 'negative',
-      message: 'เกิดข้อผิดพลาดในการบันทึกข้อมูล'
+      message: 'เกิดข้อผิดพลาดในการบันทึกข้อมูล',
+      position: 'top'
     });
   }
 };
diff --git a/frontend_management/pages/instructor/courses/index.vue b/frontend_management/pages/instructor/courses/index.vue
index eb0fa8fa..13f84d74 100644
--- a/frontend_management/pages/instructor/courses/index.vue
+++ b/frontend_management/pages/instructor/courses/index.vue
@@ -196,6 +196,47 @@
         </q-card-actions>
       </q-card>
     </q-dialog>
+
+    <!-- Clone Course Dialog -->
+    <q-dialog v-model="cloneDialog">
+      <q-card style="min-width: 400px">
+        <q-card-section class="row items-center q-pb-none">
+          <div class="text-h6">ทำสำเนาหลักสูตร</div>
+          <q-space />
+          <q-btn icon="close" flat round dense v-close-popup />
+        </q-card-section>
+
+        <q-card-section>
+          <div class="mb-4">
+            กรุณาระบุชื่อสำหรับหลักสูตรใหม่
+          </div>
+          <q-input
+            v-model="cloneCourseTitleTh"
+            label="ชื่อหลักสูตร (ภาษาไทย)"
+            outlined
+            autofocus
+            class="mb-4"
+            :rules="[val => !!val || 'กรุณากรอกชื่อหลักสูตรภาษาไทย']"
+          />
+          <q-input
+            v-model="cloneCourseTitleEn"
+            label="Course Name (English)"
+            outlined
+            :rules="[val => !!val || 'Please enter course name in English']"
+          />
+        </q-card-section>
+
+        <q-card-actions align="right" class="text-primary q-pt-none q-pb-md q-px-md">
+          <q-btn flat label="ยกเลิก" v-close-popup color="grey" />
+          <q-btn 
+            label="ยืนยันการทำสำเนา" 
+            color="primary" 
+            @click="confirmClone"
+            :loading="cloneLoading"
+          />
+        </q-card-actions>
+      </q-card>
+    </q-dialog>
   </div>
 </template>
 
@@ -296,15 +337,45 @@ const formatDate = (date: string) => {
     year: '2-digit'
   });
 };
+// Clone Dialog
+const cloneDialog = ref(false);
+const cloneLoading = ref(false);
+const cloneCourseTitleTh = ref('');
+const cloneCourseTitleEn = ref('');
+const courseToClone = ref<CourseResponse | null>(null);
 
 const duplicateCourse = (course: CourseResponse) => {
-  $q.notify({
-    type: 'info',
-    message: `กำลังทำสำเนา "${course.title.th}"...`,
-    position: 'top'
-  });
+  courseToClone.value = course;
+  cloneCourseTitleTh.value = `${course.title.th} (Copy)`;
+  cloneCourseTitleEn.value = `${course.title.en} (Copy)`;
+  cloneDialog.value = true;
 };
 
+const confirmClone = async () => {
+  if (!courseToClone.value || !cloneCourseTitleTh.value || !cloneCourseTitleEn.value) return;
+
+  cloneLoading.value = true;
+  try {
+    const response = await instructorService.cloneCourse(courseToClone.value.id, cloneCourseTitleTh.value, cloneCourseTitleEn.value);
+    $q.notify({
+      type: 'positive',
+      message: response.message || 'ทำสำเนาหลักสูตรสำเร็จ',
+      position: 'top'
+    });
+    cloneDialog.value = false;
+    fetchCourses(); // Refresh list
+  } catch (error: any) {
+    $q.notify({
+      type: 'negative',
+      message: error.data?.message || 'ไม่สามารถทำสำเนาหลักสูตรได้',
+      position: 'top'
+    });
+  } finally {
+    cloneLoading.value = false;
+  }
+};
+
+
 const confirmDelete = (course: CourseResponse) => {
   $q.dialog({
     title: 'ยืนยันการลบ',
diff --git a/frontend_management/services/instructor.service.ts b/frontend_management/services/instructor.service.ts
index 1109816e..1c81d8ca 100644
--- a/frontend_management/services/instructor.service.ts
+++ b/frontend_management/services/instructor.service.ts
@@ -305,6 +305,18 @@ export const instructorService = {
         return await authRequest<ApiResponse<void>>(`/api/instructors/courses/set-draft/${courseId}`, { method: 'POST' });
     },
 
+    async cloneCourse(courseId: number, titleTh: string, titleEn: string): Promise<ApiResponse<CourseResponse>> {
+        return await authRequest<ApiResponse<CourseResponse>>(`/api/instructors/courses/${courseId}/clone`, {
+            method: 'POST',
+            body: {
+                title: {
+                    en: titleEn,
+                    th: titleTh
+                }
+            }
+        });
+    },
+
     async getEnrolledStudents(
         courseId: number,
         page: number = 1,