body{font-family:-apple-system,Segoe UI,Roboto,sans-serif;max-width:720px;margin:40px auto;padding:0 16px;color:#222;line-height:1.6}
nav a{margin-right:16px;color:#2563eb;text-decoration:none}
article{border-bottom:1px solid #eee;padding:16px 0}
small{color:#888}