Here are some interesting CSS notification code examples.
Alert message
Dev: Swarup Kumar Kuila
Materialize.css Alert Message
Dev: booster.click
Notifications, Alerts, Modals
Dev: DevTips
Notification Animation
Dev: Simeon Simeonoff
Pure CSS/JS Toast Notification
Dev: Pierre Smith
Notifications
Dev: Hampus Persson
Pulsing Notification
Dev: Derek Wheelden
Popup Scroll Notification
Dev: Zeinab Abounassif
CSS Notification Boxes
Dev: Michael Wales
CSS animated notification badge
Dev: sjmcpherson
Notification popups
Dev: Icebob
Envelope, a Pure CSS Icon
Dev: Rafael González
Notifications
Dev: Kelsey Santangelo
Thanks for notifications
Dev: Piotr Galor
Only CSS Notification alert
Dev: Vijaya Kumar Vulchi
A notification menu!
Dev: sean_codes
CSS/LESS notification styles
Dev: Tuomas Pöyry
Fake Recent Sales Notification Popup
Dev: KARTHICK KUMAR
Notification
Dev: Rock Starwind
New alert messages bootstrap 3 font awesome
Dev: Jaime
Pop up social feed notification
Dev: Nooray Yemon
Flash Message (Error/Success)
Dev: Julie Park
Mail Notification
Dev: Aaron Iker
Notification Bell Icon Layered Shake Animation Effect
Dev: brian1983
Icons Sweet Alert Personnalisé
Dev: KAM3LEON
Notification bell animation
Dev: Benjamin Sterling
Notification Badge III
Dev: Gokul S
Circle notifications
Dev: Adam Mortka
Dribbble Card
Dev: Joe Watkins