JoyM268/CryptoTrack ? reverse-engineered prompt

Build me a cryptocurrency tracker web app where people can sign up, log in, and keep an eye on their favorite coins in one place. I want a clean dashboard that shows live crypto prices, lets users search for coins, and add or remove them from a personal portfolio and watchlist. The portfolio page should show basic performance info like profit or loss, allocation charts, top gainers and losers, and let users see values in different fiat currencies. Please also add dark mode with the setting saved, and make it easy to download the portfolio report as both PDF and CSV. Use real market data for prices and currency conversion, and make the UI feel modern and responsive. If you need current API or library details, look them up online and use the latest practical approach.