.calculator{background-color:#fff;padding:20px;border-radius:8px;box-shadow:0 4px 8px rgb(0 0 0 / .2);max-width:450px;margin:20px auto;font-family:Arial,sans-serif}.calculator h2{color:#333;text-align:center}.calculator label{font-weight:700;font-size:1em}.calculator input[type="number"]{width:96%;max-width:100%;padding:8px;margin-top:5px;margin-bottom:15px;border:1px solid #ccc;border-radius:4px}.calculator .btn{width:100%;padding:10px;background-color:#fff;color:#111;border:1px solid gray;border-radius:4px;cursor:pointer}.calculator .btn:hover{background-color:#e6e6e6}.calculator .result{margin:10px 0 0;font-size:0.9em;text-align:center;color:darkred;height:50px}