body {
  max-width: 700px;
  margin: 40px auto;
  padding: 0 20px;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  color: #333;
}
h1 { color: #2c3e50; }
a { color: #3498db; text-decoration: none; }
a:hover { text-decoration: underline; }