body {
    font-family: 'Helvetica', sans-serif;
    background-color: #ffffff;
    margin: 0;
    padding: 0;
}

#container {
    max-width: 800px;
    margin: 30px auto;
    border: 1px solid #dee2e6;
    border-radius: 12px;
    background-color: #f0f0f0;
    padding: 20px;
}

header {
    background-color: #28a745;
    color: white;
    padding: 15px;
    text-align: center;
}

main {
    padding: 20px;
    line-height: 1.6;
}

footer {
    background-color: #495057;
    color: white;
    text-align: center;
    padding: 10px;
}