body {
  max-width: 42em;
  margin: auto;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
}

header, footer {
  margin: 2em 0;
}

.note {
  border-left: 4px solid #888;
  padding: 0.5em 1em;
  background: #f5f5f5;
}

.date {
  color: #666;
  font-size: 0.9em;
}