GitAuto: Add a new icon on the top right to switch this entire website between dark mode and light mode

Resolves #80

What is the feature

This feature introduces a new icon located at the top right corner of the website that allows users to switch between dark mode and light mode. When a user clicks on the icon, the website's theme will toggle between dark and light modes, providing a personalized viewing experience.

Why we need the feature

Implementing a dark mode enhances user experience by catering to individual preferences and environmental lighting conditions. Dark mode can reduce eye strain in low-light environments and improve battery life on devices with OLED screens. Offering a theme switcher directly on the website empowers users to choose their preferred mode without relying on system settings or browser extensions.

How to implement and why

Design the Toggle Icon: Create an intuitive icon (e.g., a moon/sun symbol) that clearly indicates its function. Place it in the top right corner to ensure visibility and accessibility.
State Management:
- Use a state management solution (like React's useState or context API) to track the current theme.
- Store the user's theme preference in localStorage to persist it across sessions.
Theming Mechanism:
- Define CSS variables for theme-dependent properties (colors, backgrounds, etc.).
- Create two sets of theme variables for dark and light modes.
Implement Theme Switch Logic:
- On toggle, update the theme state and apply the corresponding CSS variables.
- Ensure that the theme change is smooth and without page reloads.
Update Global Styles:
- Modify the global CSS or stylesheets to reference the CSS variables.
- Update styles in the pages directory to use the theme variables, ensuring consistency across all pages.
Accessibility Considerations:
- Verify that contrast ratios meet accessibility standards in both themes.
- Test the feature with assistive technologies to ensure it doesn't hinder accessibility.
Testing:
- Test the theme switcher across different browsers and devices.
- Confirm that the theme preference persists and loads correctly on page refresh and navigation.

Implementing the feature step by step ensures a robust integration that enhances user satisfaction while maintaining website performance and accessibility standards.

About backward compatibility

The addition of the theme switcher is backward compatible. Users who do not interact with the new icon will experience the website in its default mode, ensuring no disruption to their current experience. Since this feature adds functionality without altering existing components or workflows, it should not affect backward compatibility. Existing styles and pages remain intact, with the theme variables providing an additional layer that enhances but does not interfere with the current design.

Test these changes locally

git checkout -b gitauto-wes/issue-#80-bd0c041c-a571-4ceb-b4f7-76c4423a7772
git pull origin gitauto-wes/issue-#80-bd0c041c-a571-4ceb-b4f7-76c4423a7772

hiroshinishio / sample-website