body {
    font-family: 'Arial', sans-serif;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

#calculator {
    background-color: #ffffff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    width: 400px;
}

h2 {
    text-align: center;
    color: #333333;
}

label {
    display: block;
    margin: 15px 0;
}

input {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    box-sizing: border-box;
}

button {
    background-color: #4caf50;
    color: white;
    padding: 10px;
    margin: 15px 0;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    width: 100%;
}

#result {
    margin-top: 20px;
    text-align: center;
}