Enhance Reader App: Speed, Design & Compatibility

I am seeking a talented developer to make edits to a reader I have started. The reader must support .txt, .pdf, and .epub files, and I want to enhance its speed and performance while also improving its visual design. This is NOT a long project, message me with screenshots of your solution fastest for the award.

Key Requirements:
- Optimize the reader for faster loading and smoother performance
- Modernize the interface with a minimalist layout
- Incorporate animations and transitions for a more dynamic user experience
- Ensure compatibility with .txt, .pdf, and .epub file formats

Ideal Skills and Experience:
- Strong experience in software development and optimization
- Proficiency in UI/UX design with a focus on modern, minimalist aesthetics
- Ability to implement animations and transitions effectively
- Experience with file format compatibility and reader applications

1. File Format Support (Core Feature)
*Open and render .pdf files (via PDF.js or similar library)
*Basic .epub rendering (via EPUB.js, without deep customization)
* TXT rendering
*Performance Optimization
*Optimize file loading speed (e.g., lazy loading, caching)
*Reduce memory usage (especially for large PDFs or EPUBs)
* Improve scroll and navigation performance

* Modern UI Design
* Implement a minimalist layout (light/dark mode toggle optional)
"Clean typography and whitespace usage
*Sidebar for navigation (e.g., table of contents or file list)
*Basic Animations/Transitions
*Smooth fade/slide transitions between sections or views
*Hover/click effects on buttons and elements
*Cross-device Compatibility
*Desktop-first design with basic responsiveness
*Test on Chrome/Edge/Firefox