body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    text-align: center;
}
header {
    background-color: #f0f0f0;
    padding: 20px;
}
header img {
    max-width: 100px;
}
main {
    padding: 20px;
}
main section {
    margin-bottom: 20px;
}
footer {
    background-color: #f0f0f0;
    padding: 20px;
}