ffalt/mah ? reverse-engineered prompt

Build me a Mahjong Solitaire game that runs in the browser and feels polished and fun to play.

I want it to have lots of replay value, with built in boards, a way to generate random boards from a seed, and the option to share or replay the same board later. It should let players choose different tile styles, themes, backgrounds, and light or dark mode, with a clean zen mode if they want fewer distractions. Please include a timer they can turn on or off, a win celebration effect, and local autosave so their progress and best times stay in the browser.

Make it support multiple languages, work well on desktop and mobile, and feel like a complete classic Mahjong Solitaire experience. Keep it free, simple, and focused on smooth gameplay. If you need to check any current docs or browser behavior, look them up online first.