pranav-aitha/Cyrptix ? reverse-engineered prompt

Build me a browser based text encryption app that runs completely on the client, with no server, no login, and no data leaving the page. I want to paste in a secret message, set a passphrase, encrypt it with strong authenticated encryption, and then have the result turn into one of several fun visual styles, like emoji, invisible zero width text, runes, occult symbols, fancy gothic text, and kaomojis. It should also decrypt back to the original message when I enter the same passphrase.

Make it feel polished and playful, with a dark mysterious look, smooth switching between the different visual modes, and clear buttons for encrypt, decrypt, copy, and reset. Keep everything working fully in the browser, and if you need current browser crypto details or Unicode handling notes, look them up online before coding. The whole thing should be easy to open as a single page and just work.