:root {
  --bg: #ffffff;
  --text: #1c1c1e;
  --muted: #6e6e73;
  --link: #0a64c2;
  --rule: #e5e5ea;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #000000;
    --text: #f5f5f7;
    --muted: #a1a1a6;
    --link: #6cb4ff;
    --rule: #2c2c2e;
  }
}
:root[data-theme="dark"] {
  --bg: #000000;
  --text: #f5f5f7;
  --muted: #a1a1a6;
  --link: #6cb4ff;
  --rule: #2c2c2e;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.55;
  -webkit-text-size-adjust: 100%;
}
main {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 16px 24px;
  overflow-wrap: anywhere;
}
h1 { font-size: 28px; line-height: 1.2; margin: 0 0 16px; }
h2 { font-size: 20px; margin: 28px 0 8px; }
p { margin: 0 0 14px; }
dt { font-weight: 600; margin-top: 14px; }
dd { margin: 4px 0 0; color: var(--text); }
a { color: var(--link); }
.small { color: var(--muted); font-size: 14px; }
footer {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px 16px 40px;
  border-top: 1px solid var(--rule);
  font-size: 15px;
}
footer a { margin-right: 14px; }