AsishRaju/450-DSA ? reverse-engineered prompt

Build me a clean React web app for the 450 DSA Cracker sheet that helps me track my progress through 400 plus data structures and algorithms questions.

I want to be able to browse questions by topic, search quickly, and mark problems as done so I can see my progress clearly. Keep everything saved in local storage so my data stays even after refreshing the page. Make it feel mobile friendly and simple to use, with a polished UI that looks good on phones and desktop. If it makes sense, add smooth animations and a dark mode toggle too.

Please use the question data already in the project, wire up the full experience, and make it easy to understand at a glance how much I have completed. If you need to check current docs or best practices while building it, go ahead and look them up online.