body{
    padding: 20px;
    font-family: Arial, sans-serif;
    margin: 0;
    background-color: #000;
    color: #fff;
}

.container{
    max-width: 800px;
    margin: 0 auto;
    background-color: #333;
    padding: 20px;
    border-radius: 8px;
}

h1{
    text-align: center;
    margin-bottom: 20px;
    font-size: 28px;
}

h2{
    margin-top: 20px;
    font-size: 22px;
    text-align: center;
}

label{
    display: block;
    margin-bottom: 5px;
    font-size: 16px;
}

input[type="number"]{
    width: 100%;
    padding: 8px;
    margin-bottom: 15px;
    border: 1px solid #555;
    border-radius: 4px;
    background-color: #222;
    color: #fff;
}

button[type="submit"]{
    width: 100%;
    padding: 10px;
    background-color: #007BFF;
    border: none;
    border-radius: 4px;
    color: #fff;
    font-size: 16px;
    cursor: pointer;
}

select{
    width: 100%;
    padding: 8px;
    margin-bottom: 15px;
    border: 1px solid #555;
    border-radius: 4px;
    background-color: #222;
    color: #fff;
}

#result{
    margin-top: 20px;
    padding: 15px;
    background-color: #444;
    border-radius: 4px;
    text-align: center;
    font-size: 18px;
}