body{font-family:Arial,sans-serif;background-color:#f4f4f4;display:flex;justify-content:center;align-items:center;height:100vh;margin:0}.calculator-container{background-color:#fff;padding:20px;border-radius:8px;box-shadow:0 0 10px rgb(0 0 0 / .1);max-width:400px;width:100%}h1{text-align:center;color:#333}label{display:block;margin-bottom:10px;color:#555}input[type="number"]{width:100%;padding:8px;margin-bottom:20px;border:1px solid #ccc;border-radius:4px}button{width:100%;padding:10px;background-color:#007BFF;color:#fff;border:none;border-radius:4px;font-size:16px;cursor:pointer}button:hover{background-color:#0056b3}#result{margin-top:20px;font-size:18px;color:#333;text-align:center}