:root {
  --brand: #2563eb; --grad: linear-gradient(135deg,#2563eb,#4f46e5);
  --bg: #eef2f9; --surface: #fff; --surface-2: #f5f7fb; --border: #e2e8f2;
  --text: #0f172a; --text-soft: #64748b; --shadow: 0 10px 30px rgba(37,99,235,.08),0 4px 12px rgba(15,23,42,.05);
}
:root[data-theme="dark"] {
  --bg:#0b1120; --surface:#141b2e; --surface-2:#1a2338; --border:#2a3550; --text:#eaf0fb; --text-soft:#9aa8c7; --shadow:0 10px 30px rgba(0,0,0,.45);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --bg:#0b1120; --surface:#141b2e; --surface-2:#1a2338; --border:#2a3550; --text:#eaf0fb; --text-soft:#9aa8c7; --shadow:0 10px 30px rgba(0,0,0,.45); }
}
* { margin:0; padding:0; box-sizing:border-box; }
body { font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif; background:var(--bg); color:var(--text); line-height:1.7; -webkit-font-smoothing:antialiased; }
.container { max-width:820px; margin:0 auto; padding:0 20px; }
header { background:var(--surface); border-bottom:1px solid var(--border); position:sticky; top:0; z-index:10; }
nav { display:flex; align-items:center; justify-content:space-between; padding:.85rem 0; }
.logo { display:flex; align-items:center; gap:.55rem; font-size:1.35rem; font-weight:800; color:var(--text); text-decoration:none; letter-spacing:-.4px; }
.logo-mark { width:34px; height:34px; border-radius:9px; background:var(--grad); color:#fff; display:flex; align-items:center; justify-content:center; font-weight:800; }
nav a.back { color:var(--brand); text-decoration:none; font-weight:600; font-size:.92rem; }
main { padding:2.5rem 0 3.5rem; }
h1 { font-size:clamp(1.8rem,4vw,2.4rem); font-weight:800; letter-spacing:-.8px; margin-bottom:.4rem; }
.updated { color:var(--text-soft); font-size:.88rem; margin-bottom:1.8rem; }
.card { background:var(--surface); border:1px solid var(--border); border-radius:16px; padding:2rem; box-shadow:var(--shadow); }
h2 { font-size:1.25rem; font-weight:800; margin:1.8rem 0 .7rem; letter-spacing:-.3px; }
h2:first-child { margin-top:0; }
p, li { color:var(--text); margin-bottom:.8rem; }
.card p, .card li { color:#334155; }
:root[data-theme="dark"] .card p, :root[data-theme="dark"] .card li { color:var(--text-soft); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .card p, :root:not([data-theme="light"]) .card li { color:var(--text-soft); } }
ul { padding-left:1.3rem; margin-bottom:.8rem; }
a { color:var(--brand); }
strong { color:var(--text); }
footer { background:var(--surface); border-top:1px solid var(--border); padding:2rem 0; text-align:center; color:var(--text-soft); font-size:.88rem; }
footer a { color:var(--brand); text-decoration:none; }
footer .foot-links { margin-bottom:.6rem; display:flex; gap:1.2rem; justify-content:center; flex-wrap:wrap; font-weight:600; }