---
id: BACK-116
title: Add dark mode toggle to web UI
status: Done
assignee:
  - '@claude'
created_date: '2025-07-06'
updated_date: '2025-07-12'
labels: []
dependencies: []
---

## Description

Implement dark mode support for the web interface with a toggle button in the navigation. Should persist user preference and provide smooth transitions between light and dark themes using Tailwind CSS dark mode classes.

## Acceptance Criteria

- [x] Add dark mode toggle button to navigation bar
- [x] Implement dark theme styles using Tailwind CSS dark mode classes
- [x] Persist user's theme preference in localStorage
- [x] Apply theme on page load based on saved preference
- [x] Provide smooth transitions between light and dark modes
- [x] Ensure all UI components work correctly in both themes
- [x] Add proper contrast ratios for accessibility compliance

## Implementation Plan

1. Explore current web UI structure and identify navigation components
2. Research Tailwind CSS dark mode configuration and setup
3. Add dark mode toggle button to navigation bar with proper styling
4. Implement theme context/state management for the React components
5. Add dark mode classes to all UI components using Tailwind's dark: prefix
6. Implement localStorage persistence for user theme preference
7. Add smooth CSS transitions between light and dark themes
8. Test all UI components in both light and dark modes
9. Verify accessibility compliance with proper contrast ratios
10. Run linting and formatting checks

## Implementation Notes

Successfully implemented comprehensive dark mode support for the web UI:

Successfully implemented comprehensive dark mode support for the web UI with stone/grey color scheme:

## Key Features Implemented:
- **Dark mode toggle button** in navigation bar with sun/moon icons
- **Theme context** using React Context API for state management  
- **localStorage persistence** to remember user's theme preference
- **System preference detection** to automatically set initial theme
- **Smooth transitions** (200ms) between light and dark themes
- **Stone/grey color scheme** instead of blue for neutral, earthy aesthetic

## Components Updated with Dark Mode:
- ThemeContext.tsx (new) - React context for theme management
- ThemeToggle.tsx (new) - Toggle button component with stone focus rings
- Navigation.tsx - Added toggle and dark mode styling with stone link colors
- Layout.tsx - Main layout background styling
- SideNavigation.tsx - Sidebar with comprehensive dark mode support and stone accents
- Modal.tsx - Modal dialogs with dark mode styling
- TaskForm.tsx - Form inputs and buttons with stone color scheme
- Board components (BoardPage, Board, TaskColumn, TaskCard) - Full kanban board with stone accents
- TaskList.tsx - List view with dark mode
- All utility components (LoadingSpinner, HealthIndicator, SuccessToast, etc.)

## Technical Implementation:
- Uses Tailwind CSS dark: variant classes throughout
- Maintains proper accessibility contrast ratios (WCAG compliant)
- Automatic theme application via document.documentElement.classList
- Responsive design preserved in both themes
- All interactive states (hover, focus, active) work in dark mode
- Stone color palette (stone-500, stone-600, etc.) for neutral accent colors

## Color Scheme:
- **Light mode**: Gray-50 backgrounds, white cards, gray-900 text, stone accents
- **Dark mode**: Gray-900 backgrounds, gray-800 cards, gray-100 text, stone accents
- **Accent colors**: Stone variants instead of blue for buttons, focus rings, and active states
- **Transitions**: Smooth 200ms color transitions for better UX
- **Status colors**: Adapted for both themes with proper contrast

All tests pass and linting checks are clean. The implementation follows the project's coding standards and maintains full backward compatibility with a neutral stone/grey color palette.
## Key Features Implemented:
- **Dark mode toggle button** in navigation bar with sun/moon icons
- **Theme context** using React Context API for state management  
- **localStorage persistence** to remember user's theme preference
- **System preference detection** to automatically set initial theme
- **Smooth transitions** (200ms) between light and dark themes

## Components Updated with Dark Mode:
- ThemeContext.tsx (new) - React context for theme management
- ThemeToggle.tsx (new) - Toggle button component
- Navigation.tsx - Added toggle and dark mode styling
- Layout.tsx - Main layout background styling
- SideNavigation.tsx - Sidebar with comprehensive dark mode support
- Modal.tsx - Modal dialogs with dark mode styling
- TaskForm.tsx - Form inputs and buttons with dark mode
- Board components (BoardPage, Board, TaskColumn, TaskCard) - Full kanban board support
- TaskList.tsx - List view with dark mode
- All utility components (LoadingSpinner, HealthIndicator, SuccessToast, etc.)

## Technical Implementation:
- Uses Tailwind CSS dark: variant classes throughout
- Maintains proper accessibility contrast ratios (WCAG compliant)
- Automatic theme application via document.documentElement.classList
- Responsive design preserved in both themes
- All interactive states (hover, focus, active) work in dark mode

## Color Scheme:
- **Light mode**: Gray-50 backgrounds, white cards, gray-900 text
- **Dark mode**: Gray-900 backgrounds, gray-800 cards, gray-100 text  
- **Transitions**: Smooth 200ms color transitions for better UX
- **Status colors**: Adapted for both themes with proper contrast

All tests pass and linting checks are clean. The implementation follows the project's coding standards and maintains full backward compatibility.
