body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  margin: 0;
  padding: 20px;
}

h1 { margin: 0 0 12px; }
input { padding: 10px; width: 240px; }
button { padding: 10px 14px; margin-left: 8px; cursor: pointer; }
hr { margin: 16px 0; }