:root {
  color-scheme: light dark;
  font: 100%/1.65 system-ui, sans-serif;
  --background: light-dark(#f5f7fb, #10151e);
  --surface: light-dark(#fff, #191f2b);
  --text: light-dark(#17243a, #eaf0fa);
  --link: light-dark(#174c9d, #a7c8ff);
  --border: light-dark(#dce4ef, #364154);
}
body { background: var(--background); color: var(--text); margin: 0 auto; max-width: 46rem; padding: 2rem 1rem; }
header { display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: .5rem 1rem; margin-bottom: 1.5rem; }
header a { font-weight: 700; }
header span { font-size: .9rem; }
main { background: var(--surface); border: 1px solid var(--border); border-radius: 1rem; padding: clamp(1.25rem, 4vw, 2.75rem); }
h1 { font-size: clamp(1.75rem, 5vw, 2.75rem); line-height: 1.15; margin-top: 0; }
p:last-child { margin-bottom: 0; }
a { color: var(--link); text-underline-offset: .15em; }