body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    background-color: #ffffff;
    color: #333;
}
header, footer {
    background-color: #f5f5f5;
    padding: 20px;
    text-align: center;
}
main {
    padding: 20px;
}
img {
    max-width: 100%;
    height: auto;
}
a {
    color: #007bff;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}