:root {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: #222;
  background: #fff;
  line-height: 1.5;
}
* { box-sizing: border-box; }
body { margin: 0; background: #fff; }
main { max-width: 760px; margin: 0 auto; padding: 48px 20px; }
h1 { margin: 0 0 12px; font-size: 1.8rem; }
h2 { margin-top: 28px; font-size: 1.15rem; }
p { margin: 10px 0; }
nav, footer { margin-top: 24px; }
nav a, footer a { margin-right: 14px; }
a { color: #174ea6; text-decoration: none; }
a:hover { text-decoration: underline; }