fix: dark mode issues for assignment

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(