body {
    margin: 1em auto;
    width: min(80%, 820px);
    font-family: sans-serif;
    font-size: small;
    border-top: 1px solid black;
    border-bottom: 1px solid black;
}

h1 {
    text-align: center
}

h2 {
    text-align: center;
    font-size: medium
}

ul {
    padding-left: 0.5em
}

li {
    padding-bottom: 0.5em;
    list-style: none
}

img {
    width: 15em;
    display: block;
    margin: 0 auto
}

span#arrow {
    vertical-align: 0.1em;
}