Implement a Features Page with Flip Cards and Dark Mode Toggle

Create a simple Features Page using HTML, CSS, and JavaScript with the following functionalities:

- Flip Cards: Each feature card should flip on hover to reveal details.
- Dark Mode Toggle: A button should toggle between light and dark mode for the entire page.
- Smooth Transitions: Ensure smooth animations for both the card flip and dark mode toggle.

Here is a sample video for reference:

https://github.com/user-attachments/assets/de81ee19-2117-45cf-91b3-f40657131ff0