body{text-align:center;background:#fff;margin:0;font-family:Arial}canvas{cursor:grab;background:#fff;border:2px solid #000}button{margin:5px;padding:6px 12px}.key-box{background:#fff;border:1px solid #ccc;border-radius:10px;max-width:400px;margin:80px auto;padding:20px;box-shadow:0 0 10px #ddd}.key-box input{width:80%;padding:8px}.error{color:red;margin-top:10px}