* {
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  line-height: 1.6;
  max-width: 640px;
  margin: 0 auto;
  padding: 2rem;
  color: #1a1a1a;
}

.back {
  display: inline-block;
  margin-bottom: 1rem;
  color: #666;
  text-decoration: none;
}

.back:hover {
  color: #000;
}

code {
  background: #f0f0f0;
  padding: 0.2em 0.4em;
  border-radius: 4px;
}