body {
    background-color: #f4f4f4;
    color: #222222;
    font-family: Arial, sans-serif;
    margin: 10px;
}

h1 {
    text-align: center;
}

nav {
    text-align: center;
    margin-bottom: 20px;
}

footer {
    text-align: center;
    margin-top: 20px;
}

img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    max-width: 100%;
    height: auto;
}

figure {
    text-align: center;
}

iframe {
    display: block;
    margin-left: auto;
    margin-right: auto;
    border: 0;
}

audio {
    display: block;
    margin-left: auto;
    margin-right: auto;
}