body {
    font-family: Arial, sans-serif;
    background-color: #f2f2f2;
    text-align: center;
    margin-top: 100px;
}

.calculator {
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    width: 300px;
    margin: auto;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
}

.calculator h2 {
    margin-bottom: 20px;
}

.calculator input,
.calculator select,
.calculator button {
    width: 90%;
    padding: 10px;
    margin: 10px 0;
    font-size: 16px;
}

button {
    background-color: #4CAF50;
    color: white;
    border: none;
    cursor: pointer;
}

button:hover {
    background-color: #45a049;
}

#result {
    margin-top: 20px;
    font-weight: bold;
    font-size: 18px;
}