Kiran-mondal/Chaturanga ? reverse-engineered prompt

Build me a polished web game version of Chaturanga, the ancient Indian strategy board game that led to modern chess.

I want an 8 by 8 board with the traditional pieces and movement rules, including Raja, Mantri, Gaja, Ashva, Ratha, and Padati. The game should let me play against a computer opponent, and also have a local two player pass and play mode on the same device. Make the interface clean and easy to use on both desktop and mobile, with clear highlights for legal moves, captures, turns, and game over.

Please add simple sound effects for movement, captures, and end of game, plus a nice historical themed look that fits the game. The computer should feel reasonably smart and adapt a bit to how I play, not just make random moves.

If anything is unclear, look up current docs online if you need to, but keep the experience lightweight and fast.