body {
    background-color: darkorange;
    font-family: monospace;
    font-size: 150%;
    display: block;
    margin: auto;
    width: 55%;
}

header {
    border-bottom: 1px solid #222;
    margin-bottom: 1rem;
}

footer {
    border-top: 1px solid #222;
    margin-top: 1rem;
}

a {
    color: blue;
    text-decoration: none;
}

section {
    background-color: orange;
    margin-left: auto;
    margin-right: auto;
    margin-top: 1rem;
    margin-bottom: 1rem;
    padding: 2rem;
}

div.center {
    display: block;
    margin: auto;
    width: 50%;
}

p.center, img.center, ul.center {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 50%;
}