body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;max-width:640px;margin:80px auto;padding:0 20px;color:#222;line-height:1.6}
h1{font-size:1.6em;margin-bottom:.2em}p{color:#555}a{color:#0366d6;text-decoration:none}