body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  margin: 0;
  padding: 0;
  background: #f7f7f7;
}

header {
  background: #333;
  color: #fff;
  padding: 1rem;
}

main {
  padding: 1rem;
}