body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f8f8f8;
    overflow-y: scroll;
}
header {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 10px 0;
}
.container {
    max-width: 1000px;
    margin: 20px auto;
    padding: 0 20px;
}
nav {
    background-color: #444;
    text-align: center;
    padding: 10px;
}
nav a {
    color: #fff;
    text-decoration: none;
    margin: 0 10px;
}
.container img {
    display: block;
    margin: 0 auto;
}