krishnasagrawal/Java-Programming-Notes ? reverse-engineered prompt

Build me a simple, clean website for this Java notes collection so people can quickly find and open the study materials and interview PDFs.

I want the homepage to feel friendly and organized, with a short intro, a search box, and sections for Java notes, interview questions, cheat sheets, and practice programs. Show each PDF as a card with the title and a quick way to open or download it. Make it easy to browse on both desktop and mobile, and keep the design lightweight and readable.

Please also add a page or section for contributing new notes or resources, since this repo is meant to grow over time. Use the content from the existing README and file names to organize everything naturally. If you need to look up current docs online for the best way to handle the PDF links or layout, go ahead.