[Feature] Implement Obsidian theme switching functionality with style adaptation

[freedeaths]

Description

Implement a comprehensive Obsidian theme switching system that allows users to dynamically change between different Obsidian community themes while ensuring proper style adaptation and compatibility.

Core Features

Theme Loading and Management

• Dynamic theme CSS loading/unloading
• Theme metadata parsing (manifest.json support)
• Theme preview functionality
• Theme validation and compatibility checking
• Error handling for corrupted/incompatible themes

Theme Discovery and Installation

• Built-in theme gallery with popular Obsidian themes
• Manual theme upload functionality (.zip or direct CSS)
• Theme URL import from GitHub/community sources
• Theme update notifications and management
• Theme backup and restore functionality

Style Adaptation System

• CSS variable mapping and normalization
• Component-specific style overrides
• Layout adaptation for different theme requirements
• Font and typography handling
• Color scheme detection (light/dark mode support)

Technical Implementation

CSS Integration

• CSS-in-JS compatibility for theme variables
• Scoped styling to prevent conflicts
• CSS custom property cascade management
• Critical CSS extraction for theme essentials
• Performance optimization for theme switching

Theme Structure Support

• Obsidian CSS variable conventions
• Plugin-specific styling support
• Mobile responsiveness adaptation
• Print stylesheet handling
• High contrast and accessibility features

Compatibility Layer

• Map Obsidian-specific selectors to React components
• Handle missing CSS classes gracefully
• Provide fallback styles for unsupported features
• Convert Obsidian plugins styles to React equivalents

User Interface

Theme Selector

• Theme picker with live previews
• Search and filter functionality
• Theme categories and tags
• User ratings and reviews integration
• Favorites and recently used themes

Settings Integration

• Theme settings panel in application preferences
• Per-theme customization options
• Theme-specific configuration persistence
• Import/export theme configurations
• Reset to default functionality

Popular Obsidian Themes to Support

• Minimal Theme
• California Coast
• ITS Theme
• Atom
• Blue Topaz
• Dracula
• Nord
• Solarized
• Tokyo Night

Technical Challenges

CSS Variable Mapping

• Map Obsidian CSS variables to application components
• Handle theme-specific custom properties
• Ensure proper inheritance and cascading
• Performance optimization for variable updates

Dynamic Loading

• Efficient CSS loading and caching
• Memory management for multiple themes
• Progressive loading for large themes
• Network optimization for remote themes

Cross-Component Integration

• Ensure theme consistency across all components
• Handle theme changes during active use
• Maintain state during theme transitions
• Smooth visual transitions between themes

Performance Considerations

• Lazy loading for non-active themes
• CSS minification and compression
• Caching strategies for theme assets
• Bundle size optimization
• Memory usage monitoring

Testing Strategy

• Visual regression testing for each theme
• Cross-browser compatibility testing
• Mobile device theme adaptation testing
• Performance benchmarking
• Accessibility testing with different themes

User Experience Goals

• Seamless theme switching without page reload
• Instant visual feedback during selection
• Preservation of user preferences and settings
• Intuitive theme discovery and management
• Consistent functionality across all themes

Priority

Medium-High - Significant feature for customization and user engagement, important for Obsidian community adoption.