:root { color-scheme: light dark; }
* { box-sizing: border-box; }

body {
  max-width: 72ch;
  margin: 0 auto;
  padding: 2rem 1rem;
  font: 16px/1.6 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

header, footer { margin: 1.5rem 0; }
nav a { margin-right: .75rem; }

a { text-underline-offset: .2em; }
h1, h2 { line-height: 1.2; }

main { margin-top: 1rem; }
article { margin: 1.25rem 0; padding: 1rem; border: 1px solid currentColor; border-radius: .5rem; }
small { opacity: .75; }