diff --git a/frontend/src/components/AppSidebar.vue b/frontend/src/components/AppSidebar.vue
index 0a45fb7e..79d05006 100644
--- a/frontend/src/components/AppSidebar.vue
+++ b/frontend/src/components/AppSidebar.vue
@@ -188,7 +188,12 @@ const addQuizzes = () => {
 			label: 'Quizzes',
 			icon: 'CircleHelp',
 			to: 'Quizzes',
-			activeFor: ['Quizzes', 'QuizForm'],
+			activeFor: [
+				'Quizzes',
+				'QuizForm',
+				'QuizSubmissionList',
+				'QuizSubmission',
+			],
 		})
 	}
 }
@@ -199,7 +204,12 @@ const addAssignments = () => {
 			label: 'Assignments',
 			icon: 'Pencil',
 			to: 'Assignments',
-			activeFor: ['Assignments', 'AssignmentForm'],
+			activeFor: [
+				'Assignments',
+				'AssignmentForm',
+				'AssignmentSubmissionList',
+				'AssignmentSubmission',
+			],
 		})
 	}
 }
diff --git a/frontend/src/components/Assignment.vue b/frontend/src/components/Assignment.vue
index f4bb1413..38e3d4b5 100644
--- a/frontend/src/components/Assignment.vue
+++ b/frontend/src/components/Assignment.vue
@@ -53,7 +53,7 @@
 						!['Pass', 'Fail'].includes(submissionResource.doc?.status) &&
 						submissionResource.doc?.owner == user.data?.name
 					"
-					class="bg-surface-blue-2 p-3 rounded-md leading-5 text-sm mb-4"
+					class="bg-surface-blue-2 text-ink-blue-2 p-3 rounded-md leading-5 text-sm mb-4"
 				>
 					{{ __("You've successfully submitted the assignment.") }}
 					{{
@@ -119,7 +119,7 @@
 					/>
 				</div>
 				<div v-else>
-					<div class="text-sm mb-4">
+					<div class="text-sm mb-2 text-ink-gray-7">
 						{{ __('Write your answer here') }}
 					</div>
 					<TextEditor
@@ -141,7 +141,10 @@
 					<div class="text-sm text-ink-gray-5 font-medium mb-2">
 						{{ __('Comments by Evaluator') }}:
 					</div>
-					<div class="leading-5" v-html="submissionResource.doc.comments"></div>
+					<div
+						class="leading-5 text-ink-gray-9"
+						v-html="submissionResource.doc.comments"
+					></div>
 				</div>
 
 				<!-- Grading -->
diff --git a/frontend/src/components/CourseOutline.vue b/frontend/src/components/CourseOutline.vue
index 42f6f0ef..291a4351 100644
--- a/frontend/src/components/CourseOutline.vue
+++ b/frontend/src/components/CourseOutline.vue
@@ -72,7 +72,7 @@
 							<div
 								class="outline-lesson pl-8 py-2 pr-4 text-ink-gray-9"
 								:class="
-									isActiveLesson(lesson.number) ? 'bg-surface-selected' : ''
+									isActiveLesson(lesson.number) ? 'bg-surface-gray-3' : ''
 								"
 							>
 								<router-link
diff --git a/frontend/src/components/SidebarLink.vue b/frontend/src/components/SidebarLink.vue
index b4b78e62..11777b45 100644
--- a/frontend/src/components/SidebarLink.vue
+++ b/frontend/src/components/SidebarLink.vue
@@ -2,7 +2,9 @@
 	<button
 		v-if="link && !link.onlyMobile"
 		class="flex h-7 cursor-pointer items-center rounded text-ink-gray-8 duration-300 ease-in-out focus:outline-none focus:transition-none focus-visible:rounded focus-visible:ring-2 focus-visible:ring-outline-gray-3"
-		:class="isActive ? 'bg-surface-white shadow-sm' : 'hover:bg-surface-gray-2'"
+		:class="
+			isActive ? 'bg-surface-selected shadow-sm' : 'hover:bg-surface-gray-2'
+		"
 		@click="handleClick"
 	>
 		<div
diff --git a/frontend/src/utils/upload.js b/frontend/src/utils/upload.js
index c54cfae4..7c43462f 100644
--- a/frontend/src/utils/upload.js
+++ b/frontend/src/utils/upload.js
@@ -56,11 +56,11 @@ export class Upload {
 			app.mount(this.wrapper)
 			return
 		} else if (file.file_type == 'PDF') {
-			this.wrapper.innerHTML = `<iframe src="https://docs.google.com/viewer?url=${
+			this.wrapper.innerHTML = `<iframe src="${
 				window.location.origin
 			}${encodeURI(
 				file.file_url
-			)}&embedded=true" width='100%' height='700px' class="mb-4" type="application/pdf"></iframe>`
+			)}" width='100%' height='700px' class="mb-4" type="application/pdf"></iframe>`
 			return
 		} else {
 			this.wrapper.innerHTML = `<img class="mb-4" src=${encodeURI(