Add theme management and settings functionality

- Introduced `ThemeManager` to handle application themes using `ttkthemes`.
- Added `SettingsWindow` for user preferences including theme selection and UI settings.
- Integrated theme selection into the main application with a menu for quick access.
- Enhanced UI components with custom styles based on the selected theme.
- Implemented tooltips for better user guidance across various UI elements.
- Updated dependencies to include `ttkthemes` for improved visual appeal.

docs/FEATURES.md

@@ -1,7 +1,49 @@
 # TheChart - Features Documentation
 
 ## Overview
-TheChart is a comprehensive medication tracking application that allows users to monitor medication intake, symptom tracking, and visualize treatment progress over time.
+TheChart is a comprehensive medication tracking application with a modern, professional UI that allows users to monitor medication intake, track symptoms, and visualize treatment progress over time.
+
+## 🎨 Modern UI/UX System (New in v1.9.5)
+
+### Professional Theme Engine
+TheChart features a sophisticated theme system powered by ttkthemes, offering 8 carefully curated professional themes.
+
+#### Available Themes:
+- **Arc**: Modern flat design with subtle shadows
+- **Equilux**: Dark theme with excellent contrast
+- **Adapta**: Clean, minimalist design
+- **Yaru**: Ubuntu-inspired modern interface
+- **Ubuntu**: Official Ubuntu styling
+- **Plastik**: Classic professional appearance
+- **Breeze**: KDE-inspired clean design
+- **Elegance**: Sophisticated dark theme
+
+#### UI Enhancements:
+- **Modern Styling**: Card-style frames, enhanced buttons, professional form controls
+- **Smart Tooltips**: Context-sensitive help for all interactive elements
+- **Improved Tables**: Better selection highlighting and alternating row colors
+- **Settings System**: Comprehensive preferences with theme persistence
+- **Responsive Design**: Automatic layout adjustments and scaling
+
+### ⌨️ Comprehensive Keyboard Shortcuts
+Professional keyboard shortcut system for efficient navigation and operation.
+
+#### File Operations:
+- **Ctrl+S**: Save/Add new entry
+- **Ctrl+Q**: Quit application (with confirmation)
+- **Ctrl+E**: Export data
+
+#### Data Management:
+- **Ctrl+N**: Clear entries
+- **Ctrl+R / F5**: Refresh data
+- **Delete**: Delete selected entry
+- **Escape**: Clear selection
+
+#### Window Management:
+- **Ctrl+M**: Manage medicines
+- **Ctrl+P**: Manage pathologies
+- **F1**: Show keyboard shortcuts help
+- **F2**: Open settings window
 
 ## Core Features
 
@@ -37,6 +79,36 @@ Each medicine includes:
 2. **Manual Configuration**: Edit `medicines.json` directly
 3. **Programmatically**: Use the MedicineManager API
 
+### ⚙️ Settings and Theme Management
+Advanced configuration system allowing users to customize their experience.
+
+#### Settings Window (F2):
+- **Theme Selection**: Choose from 8 professional themes with live preview
+- **UI Preferences**: Font scaling, window behavior options
+- **About Information**: Detailed application and version information
+- **Tabbed Interface**: Organized settings categories for easy navigation
+
+#### Theme Features:
+- **Real-time Switching**: No restart required for theme changes
+- **Persistence**: Selected theme remembered between sessions
+- **Quick Access**: Theme menu for instant switching
+- **Fallback Handling**: Graceful handling if themes fail to load
+
+### 💡 Smart Tooltip System
+Context-sensitive help system providing guidance throughout the application.
+
+#### Tooltip Types:
+- **Pathology Scales**: Usage guidance for symptom tracking
+- **Medicine Checkboxes**: Medication information and dosage details
+- **Action Buttons**: Functionality description with keyboard shortcuts
+- **Form Controls**: Input guidance and format requirements
+
+#### Features:
+- **Delayed Display**: Non-intrusive timing (500-800ms delay)
+- **Theme-aware Styling**: Tooltips match selected theme
+- **Smart Positioning**: Automatic placement to avoid screen edges
+- **Rich Content**: Multi-line descriptions with formatting
+
 ### 💊 Advanced Dose Tracking
 Comprehensive dose tracking system that records exact timestamps and dosages throughout the day.
 
@@ -192,24 +264,49 @@ Comprehensive keyboard shortcuts for efficient navigation and data entry.
 
 ## Technical Architecture
 
-### 🏗️ Modular Design
-- **MedicineManager**: Core medicine CRUD operations
-- **PathologyManager**: Symptom and pathology management
-- **GraphManager**: All graph-related operations and visualizations
-- **UIManager**: User interface creation and management
-- **DataManager**: CSV operations and data persistence
+### <EFBFBD> Modern UI Architecture
+- **ThemeManager**: Centralized theme management with dynamic switching
+- **TooltipManager**: Smart tooltip system with context-sensitive help
+- **UIManager**: Enhanced UI component creation with theme integration
+- **SettingsWindow**: Advanced configuration interface with persistence
 
-### 🔧 Configuration Management
-- **JSON-based Configuration**: `medicines.json` and `pathologies.json`
-- **Dynamic Loading**: Runtime configuration updates
-- **Validation**: Input validation and error handling
-- **Backward Compatibility**: Seamless updates and migrations
+### 🏗️ Core Application Design
+- **MedicineManager**: Core medicine CRUD operations with JSON persistence
+- **PathologyManager**: Symptom and pathology management system
+- **GraphManager**: Professional graph rendering with matplotlib integration
+- **DataManager**: Robust CSV operations and data persistence with validation
 
-### 📈 Data Processing
+### 🔧 Configuration and Data Management
+- **JSON-based Configuration**: `medicines.json` and `pathologies.json` for easy management
+- **Dynamic Loading**: Runtime configuration updates without restarts
+- **Data Validation**: Comprehensive input validation and error handling
+- **Backward Compatibility**: Seamless updates and migrations across versions
+
+### 📈 Advanced Data Processing
 - **Pandas Integration**: Efficient data manipulation and analysis
-- **Matplotlib Visualization**: Professional graph rendering
-- **Robust Parsing**: Handles various data formats and edge cases
-- **Real-time Calculations**: Dynamic dose totals and averages
+- **Real-time Calculations**: Dynamic dose totals, averages, and statistics
+- **Robust Parsing**: Handles various data formats and edge cases gracefully
+- **Performance Optimization**: Efficient batch operations and caching
+
+## UI/UX Technical Implementation
+
+### 🎭 Theme System Architecture
+- **Multiple Theme Support**: 8 curated professional themes
+- **Dynamic Style Application**: Real-time theme switching without restart
+- **Color Extraction**: Automatic color scheme detection and application
+- **Fallback Mechanisms**: Graceful handling when themes fail to load
+
+### 💡 Enhanced User Experience
+- **Smart Tooltips**: Context-sensitive help with delayed, non-intrusive display
+- **Modern Styling**: Card-style frames, enhanced buttons, professional form controls
+- **Improved Tables**: Better selection highlighting and alternating row colors
+- **Responsive Design**: Automatic layout adjustments and proper scaling
+
+### ⚙️ Settings and Persistence
+- **Configuration Management**: Theme and preference persistence across sessions
+- **Tabbed Settings Interface**: Organized categories for easy navigation
+- **Live Preview**: Real-time theme preview in settings
+- **Error Recovery**: Robust handling of corrupted settings with defaults
 
 ## Deployment and Distribution