1body{
 2    font-family: sans-serif;
 3    margin: 40px auto;
 4    padding: 0px 10px;
 5    max-width: 650px;
 6    line-height: 1.5;
 7    background-color: whitesmoke;
 8}
 9
10textarea {
11    height: 400px;
12    width: 100%;
13}
14
15form > *:not(label, [type=submit], [type=checkbox]) {
16    width: 100%;
17    display: block;
18    box-sizing: border-box;
19    margin-bottom: 1em;
20}
21
22pre {
23    background-color: gainsboro;
24    padding: 1em;
25}
26
27nav > * {
28    margin-right: 10px;
29}
30
31main > nav {
32    margin-top: 1em;
33}
34
35footer {
36    padding-top: 1em;
37    margin-top: 1em;
38    border-top: 1px solid;
39}
40
41.link::before {
42    content: "↗ ";
43}
44
45.hidden {
46    display: none !important;
47}