body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f7f8fb;
  color: #222;
}
main {
  max-width: 720px;
  margin: 12vh auto;
  padding: 32px;
  background: white;
  border-radius: 18px;
  box-shadow: 0 16px 50px rgba(0,0,0,.08);
}
h1 {
  margin-top: 0;
}
.muted {
  color: #667085;
}