Fix Dark mode UI issues

Is your feature request related to a problem? Please describe.

Currently, DevBlog’s dark mode has multiple UI issues that affect usability and readability. Problems include poor contrast, inconsistent theme application, unreadable text/images, invisible shadows/borders, unstyled modals, and third-party components not adapting to dark mode. The theme toggle also does not persist user preference.

Describe the solution you'd like

• Ensure all UI elements respond correctly to dark mode.
• Improve contrast and readability for text and backgrounds.
• Adjust images, icons, borders, and shadows to fit dark mode.
• Make modals, overlays, and third-party components respect the dark theme.
• Persist theme preference using localStorage.
• Implement smooth transitions when switching themes.
• Optionally, respect the system prefers-color-scheme setting.

Describe alternatives you've considered

• Provide only a light mode (not preferred).
• Manual theme switching via CSS (less user-friendly).

Additional context Fixing these issues will improve accessibility, readability, and overall user experience in DevBlog’s dark mode.

Request for assignment I would like to work on resolving these dark mode issues. Kindly assign this issue to me under hacktoberfest.