[Enhancement] Notification card stack background does not adapt to light/dark mode

[kodebarista]

Issue/Description:
Currently, the background color of the stacked notification cards appears identical in both light and dark modes. This breaks visual consistency and creates contrast imbalance in both modes, making the UI feel incorrect and less adaptive to the system theme.

Version:

Steps to Reproduce:

• Open notifications panel
• Switch between light mode and dark mode
• Observe the stacked notification card background color

Expected Behavior:
The notification card stack background should adapt to the active theme:

• Use a lighter surface color in light mode
• Use a darker surface color in dark mode
  Maintaining proper contrast and consistency with the system theme.

Other Notes: