Add dark/light mode toggle to the frontend

[vestor-dev]

The UI is currently dark-only. Add theme support:

(1) Use next-themes for theme management.
(2) Persist preference in localStorage.
(3) Respect OS prefers-color-scheme as default.
(4) Add a sun/moon toggle button to the navbar.
(5) Ensure all custom CSS variables have light-mode equivalents in globals.css.

[Hollujay]

I would like to work on this issue because I will get it done.

[Kend07]

Hello maintainer, I have experience with UI components, CSS, HTML, Typescript and PplgSQL, I participated in the previous GranfFox Campaign (First Ofifcial Campaign) I will take over and deliver a HQ PR. Let me work for you.

[cristianFleita]

Hi team, I’d love to tackle this theme support issue.

I plan to leverage my React and TypeScript experience to configure next-themes in the root layout, which will cleanly handle both the OS prefers-color-scheme detection and localStorage persistence. I'll then build a functional sun/moon toggle component for the navbar and map out all the required complementary light-mode CSS variables in globals.css to ensure the entire UI transitions smoothly while preserving existing styles.

[elcabasa]

Hi team,

I would love to take on this issue! Adding light mode support is a fantastic quality-of-life upgrade for user accessibility and comfort.

I am ready to implement the complete theme management flow following your specifications:

• Theme Management Setup: Integrate next-themes to manage runtime state changes seamlessly across the application.
• Preference Persistence: Wire the provider to persist user theme preferences in localStorage and smoothly fall back to the system's prefers-color-scheme as the default on initial load.
• Navbar Controls: Create and add an intuitive, accessible sun/moon toggle button inside the global navbar.
• CSS Styling Mirroring: Audit globals.css to define and map proper light-mode equivalents for all existing custom CSS variables, ensuring full UI consistency with no visual breakage.

Could you please assign this issue to me? I'm excited to get this implemented!

[grantfox-oss]

🦊 GrantFox — @Kend07 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #40)
2. Your PR will be reviewed by the CortexRail maintainers

Good luck! Track your progress on GrantFox.