body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f9;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}
.container {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
.calculator {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
input, select, button {
    padding: 10px;
    border-radius: 5px;
    border: 1px solid #ccc;
}
button {
    background-color: #007bff;
    color: white;
    cursor: pointer;
}
button:hover {
    background-color: #0056b3;
}
#result {
    margin-top: 10px;
    font-size: 1.2em;
    color: #333;
}