:root { --bg: #ffffff; --fg: #1d1d1f; --muted: #5b5b62; --rule: #e3e3e8; --link: #0b57d0; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --bg: #131316; --fg: #ececf0; --muted: #a3a3ad; --rule: #2c2c33; --link: #8ab4f8; }
}
:root[data-theme="dark"] { --bg: #131316; --fg: #ececf0; --muted: #a3a3ad; --rule: #2c2c33; --link: #8ab4f8; }
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
main { max-width: 42rem; margin: 0 auto; padding: 3rem 16px 4rem; }
header { border-bottom: 1px solid var(--rule); padding-bottom: 1rem; margin-bottom: 2rem; }
.brand { font-weight: 700; font-size: 1.25rem; letter-spacing: -0.01em; color: var(--fg); text-decoration: none; }
h1 { font-size: 1.75rem; line-height: 1.25; margin: 0 0 0.5rem; letter-spacing: -0.02em; }
h2 { font-size: 1.15rem; margin: 2rem 0 0.5rem; }
p, li { color: var(--fg); }
.muted { color: var(--muted); font-size: 0.9rem; }
a { color: var(--link); }
footer { border-top: 1px solid var(--rule); margin-top: 3rem; padding-top: 1rem; font-size: 0.9rem; }
footer a { margin-right: 1rem; }