Add Dark Mode Support

[Durgesh4993]

Description

The website currently only supports a light theme. Adding dark mode will improve usability for users in low-light environments.

Steps to Implement

1. Define CSS variables for light and dark themes.
2. Add a toggle switch to switch between themes.
3. Store user preferences in local storage.
4. Test the feature across all pages and devices.

Expected Outcome

Users can toggle between light and dark modes seamlessly.

[Aerospace-prog]

I want to tackle the "Add Dark Mode Support" issue. I've reviewed the steps and am confident that I can implement them.