Summary

Add a Dark Mode toggle to the website to allow users to switch between light and dark themes.

Motivation

Many users prefer dark mode, especially in low-light conditions, as it reduces eye strain and gives a modern look and feel. Currently, the website only has a light theme.

Possible Solution

Add a toggle button in the header or sidebar.
Update CSS variables or classes to switch between light and dark themes.
Ensure all UI elements (text, background, buttons, cards) adjust properly.