feat: Implement Dark Mode Toggle [ ECWOC ]

[trivedikavya]

Description:
The website currently only supports a light theme. Adding a Dark Mode would improve accessibility and user experience, especially for developers who prefer darker themes.

Suggested Change:

• Add a toggle button in the header (navbar).
• Use JavaScript to toggle a .dark-mode class on the body.
• Update CSS variables in style.css to define dark colors (e.g., changing background to dark gray and text to white).

Tech Stack:
HTML, CSS (Variables), JavaScript.

Contribution:
@sayeeg-11 I am eager to work on this! Please assign it to me.

[github-actions]

Thanks @trivedikavya! 👋
Your issue is important — maintainers will take a look soon.

Before contributing, please note:
🔹 Make sure you check #23 – Important Contributing Guidelines for OpenSource Compass
🔹 PRs should be raised only after the issue is assigned

[rafiaminhaj9939-del]

Hi @sayeeg-11 👋
I’d like to work on this issue as part of FCWOC.

I have experience with HTML, CSS, and JavaScript, and I’ve implemented dark mode toggles before using CSS variables and localStorage for persistence.

Please let me know if I can take this up.
Thanks!

[magic-peach]

@sayeeg-11 I would like to work on this issue as a part of SWOC'26,please assign it to me

[VishalRaut2106]

Hi Sayee, I’m a contributor from ECWOC and would like to work on this issue.
Please assign it to me. Thanks!

[sayeeg-11]

@magic-peach
@trivedikavya
@VishalRaut2106
@rafiaminhaj9939-del

please go through the assigned issues first, to avoid duplication.