body {
  font-family: Helvetica, Arial, sans-serif;
  max-width: 820px;
  margin: 40px auto;
  padding: 0 20px;
  color: #111;
  line-height: 1.6;
}
header h1 { font-size: 40px; margin-bottom: 4px; }
nav a { margin-right: 18px; text-decoration: none; color: #555; }
nav a:hover { color: #000; }
section { margin-top: 48px; }
img { border: 1px solid #eee; margin-bottom: 12px; }
footer { margin-top: 64px; font-size: 14px; color: #888; }