*,:after,:before{box-sizing:border-box}body,html{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Helvetica Neue,sans-serif;line-height:1.5;color:#111;background:#fff}main{max-width:720px;margin:0 auto;padding:2rem 1rem}h1{font-size:2rem;margin-bottom:.5rem}