v2.1.0: UI/UX improvements and design consistency

- Fixed recurring task checkbox height to match other inputs
- Harmonized goal card design with consistent styling
- Refined hover borders to be thinner and more subtle (0.5px)
- Improved visual consistency across all interactive elements
- Enhanced goal cards with period badges and modern design
- Updated README with latest features and improvements

Version 2.0.0 - Complete UI/UX Redesign

Major visual overhaul with:
- Modern card-based timer layout
- Glassmorphism effects
- Refined Sunset and Rose Garden themes
- Enhanced animations and interactions
- Improved responsive design
- Complete English documentation

This is a major release with significant visual improvements and better user experience across all devices.