body{font-family:Arial,Helvetica,sans-serif;max-width:640px;margin:40px auto}label{display:block;margin-top:12px}input[type="text"],input[type="date"]{width:100%;padding:8px;box-sizing:border-box}button{margin-top:12px;padding:10px 16px}#result{margin-top:20px}#qr{margin-top:10px}pre{background:#f6f6f6;padding:10px;overflow:auto}