/* Mobile-first, no dependencies. */
:root { color-scheme: light dark; }
body { font: 17px/1.55 system-ui, -apple-system, "Segoe UI", sans-serif; margin: 0; padding: 0 1rem; color: #1a1a1a; background: #fff; }
header, main, footer { max-width: 42rem; margin: 0 auto; }
header { padding: 1rem 0 .5rem; border-bottom: 1px solid #ccc; }
.brand { font-size: 1.3rem; font-weight: 700; margin: 0 0 .25rem; }
nav a { margin-right: .9rem; }
h1 { font-size: 1.6rem; margin: 1.2rem 0 .6rem; }
h2 { font-size: 1.15rem; margin: 1.4rem 0 .3rem; }
a { color: #0b57d0; }
.small { color: #555; font-size: .85rem; }
footer { padding: 1rem 0 2rem; border-top: 1px solid #ccc; font-size: .9rem; color: #444; }
@media (prefers-color-scheme: dark) {
  body { background: #121212; color: #e8e8e8; }
  a { color: #8ab4f8; }
  header, footer { border-color: #444; }
  .small, footer { color: #aaa; }
}