:root { color-scheme: light dark; --background: #f8fafc; --surface: #ffffff; --text: #17212b; --muted: #596675; --line: #dce3e9; --accent: #185abd; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--background); color: var(--text); font: 16px/1.8 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; overflow-wrap: anywhere; }
header, main, footer { max-width: 780px; margin: auto; padding: 24px; }
header { display: flex; align-items: center; justify-content: space-between; gap: 16px; border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; color: var(--text); text-decoration: none; }
nav { display: flex; flex-wrap: wrap; gap: 16px; }
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; border-radius: 2px; }
main { background: var(--surface); }
h1 { margin: 8px 0 16px; font-size: clamp(26px, 5vw, 36px); line-height: 1.3; letter-spacing: -.02em; }
h2 { margin: 36px 0 12px; font-size: 21px; line-height: 1.5; }
p { margin: 12px 0; }
ul { padding-inline-start: 24px; }
li { margin: 8px 0; }
.meta, footer { color: var(--muted); font-size: 14px; }
.summary { padding: 16px 20px; margin: 24px 0; background: var(--background); border-inline-start: 3px solid var(--accent); }
dl { margin: 16px 0; }
dt { font-weight: 650; margin-top: 16px; }
dd { margin: 4px 0 0; }
footer { border-top: 1px solid var(--line); }
@media (max-width: 480px) { header, main, footer { padding: 20px; } header { align-items: flex-start; flex-direction: column; gap: 8px; } }
@media (prefers-color-scheme: dark) { :root { --background: #12171d; --surface: #191f26; --text: #e7edf4; --muted: #a8b4c2; --line: #343e4a; --accent: #92beff; } }
@media print { :root { --background: #fff; --surface: #fff; --text: #000; --muted: #333; --line: #ccc; --accent: #000; } header nav { display: none; } main { max-width: none; } h2 { break-after: avoid; } }