body {
  margin: 0;
  background: #fff;
  color: #222;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

header, main, footer {
  max-width: 700px;
  margin: 0 auto;
  padding: 0 16px;
}

header {
  padding-top: 24px;
  border-bottom: 1px solid #ddd;
}

header a {
  color: inherit;
  text-decoration: none;
  font-weight: bold;
}

h1 { font-size: 1.8em; }
h2 { font-size: 1.3em; margin-top: 2em; }
h3 { font-size: 1.05em; }

a { color: #0645ad; }

footer {
  margin-top: 48px;
  padding-top: 16px;
  padding-bottom: 32px;
  border-top: 1px solid #ddd;
  font-size: 0.9em;
  color: #555;
}

footer a { margin-right: 16px; }