Fixed bug with not being able to download CSV files.
Added XFrameOptionMiddleware, X_FRAME_OPTION is not set to DENY because it clashes with assignment preview.
Removed old and unnecessary code.
Replaced floats with flexbox.
Simplified CSS and removed unused CSS.
Added CSS for tables in admin panel to better work on mobile.
Added basic error pages for 400, 403, 404, and 500.
Restricted the access to roleselect view to is_admin_on_anything = True
Fixed bug with not being able to download CSV files. Added XFrameOptionMiddleware, X_FRAME_OPTION is not set to DENY because it clashes with assignment preview. Removed old and unnecessary code. Replaced floats with flexbox. Simplified CSS and removed unused CSS. Added CSS for tables in admin panel to better work on mobile. Added basic error pages for 400, 403, 404, and 500. Restricted the access to roleselect view to is_admin_on_anything = True