body {
    font-family: sans-serif;
    color: #333;
    margin:0;
}

header {
    background-color: #f0f0f0;
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid #ccc;
}

header h1 {
    margin: 0;
    font-size: 2em;
}

header nav {
    margin-top: 10px;
}

header nav a {
    padding: 10px 15px;
    text-decoration: none;
    color: #333;
    border-radius: 5px;
    margin: 0 5px;
}

header nav a:hover {
    background-color: #ddd;
}

header nav a[aria-selected="true"] {
    background-color: #bbb;
    color: white;
}

main {
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}