.calculator{background-color:#fff;padding:20px;border-radius:5px;box-shadow:0 0 10px rgba(0,0,0,.2);text-align:center}.calculator h1{font-size:24px}.calculator label{display:block;margin-top:10px;font-weight:700}.calculator input{width:100%;padding:10px;margin:5px 0;border:1px solid #ccc;border-radius:4px}.calculator button{width:100%;padding:10px;margin-top:10px;background-color:#007BFF;color:#fff;border:none;border-radius:4px;cursor:pointer}.calculator button:hover{background-color:#0056b3}p#result{margin-top:10px;font-weight:700}