:root{
  --bg:#f6f9fc;
  --fg:#0f172a;
  --card:#ffffff;
  --muted:#eef2f7;
  --muted-fg:#475569;
  --border:#e2e8f0;
  --primary:#1d4ed8;
  --primary-2:#2563eb;
  --radius:14px;
  --shadow:0 10px 25px rgba(2,6,23,.08);
  --shadow-sm:0 6px 18px rgba(2,6,23,.06);
  --max:1200px;
  --font: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}
html.dark{
  --bg:#0b1220;
  --fg:#e5e7eb;
  --card:#0f172a;
  --muted:#111c33;
  --muted-fg:#9ca3af;
  --border:#1f2a44;
  --primary:#60a5fa;
  --primary-2:#3b82f6;
  --shadow:0 10px 30px rgba(0,0,0,.35);
  --shadow-sm:0 8px 22px rgba(0,0,0,.28);
}
*{box-sizing:border-box}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--fg);line-height:1.6}
a{color:inherit;text-decoration:none}
.container{max-width:var(--max);margin:0 auto;padding:0 16px}
header.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.85);backdrop-filter: blur(10px);border-bottom:1px solid var(--border)}
html.dark header.site-header{background:rgba(15,23,42,.85)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800}
.logo{width:32px;height:32px;border-radius:10px;background:var(--primary);display:grid;place-items:center;color:white;font-weight:800}
.nav{display:flex;align-items:center;gap:18px}
.nav a{font-size:14px;color:var(--muted-fg)}
.nav a:hover{color:var(--fg)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 14px;border-radius:12px;border:1px solid var(--border);background:transparent;cursor:pointer;font-weight:600}
.btn-primary{background:var(--primary);border-color:transparent;color:white}
.btn-primary:hover{background:var(--primary-2)}
.btn-ghost{background:transparent;border-color:transparent;color:var(--fg)}
.btn-ghost:hover{background:rgba(100,116,139,.12)}
.icon-btn{width:40px;height:40px;padding:0;border-radius:12px}
.mobile-toggle{display:none}
.mobile-nav{display:none;border-top:1px solid var(--border);padding:14px 0}
.hero{position:relative;overflow:hidden;padding:64px 0 96px;background:linear-gradient(to bottom, rgba(29,78,216,.08), transparent)}
.hero-badge{display:inline-flex;align-items:center;gap:8px;padding:8px 12px;border-radius:999px;background:rgba(29,78,216,.10);color:var(--primary);font-weight:700;font-size:13px}
h1{font-size:44px;line-height:1.1;margin:18px 0}
h2{font-size:28px;margin:0 0 14px}
.lead{font-size:18px;color:var(--muted-fg);max-width:760px;margin:0 auto}
.center{text-align:center}
.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.main-grid{grid-template-columns:2fr 1fr}
@media (max-width: 1024px){.main-grid{grid-template-columns:1fr}.grid-3{grid-template-columns:1fr}.grid-2{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-sm);overflow:hidden}
.card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}
.card, .card:hover{transition:all .25s ease}
.card-body{padding:18px}
.badge{display:inline-flex;align-items:center;padding:6px 10px;border-radius:999px;background:rgba(2,6,23,.06);color:var(--fg);font-size:12px;font-weight:700}
html.dark .badge{background:rgba(148,163,184,.12)}
.meta{display:flex;flex-wrap:wrap;gap:14px;color:var(--muted-fg);font-size:13px;margin-top:10px}
.thumb{aspect-ratio:16/10;background:linear-gradient(135deg, rgba(29,78,216,.14), rgba(29,78,216,.03));display:grid;place-items:center;font-size:44px}
.thumb.featured{aspect-ratio:16/9;background:linear-gradient(135deg, var(--primary), rgba(29,78,216,.6));color:white;position:relative}
.thumb.featured::after{content:"";position:absolute;inset:0;background:linear-gradient(to top, rgba(0,0,0,.55), transparent)}
.thumb-featured-inner{position:absolute;left:18px;right:18px;bottom:16px;z-index:1}
.thumb-featured-inner h2{color:white;margin:8px 0 0;font-size:28px}
.card-title{font-size:18px;margin:10px 0 8px}
.card-excerpt{color:var(--muted-fg);font-size:14px;margin:0 0 14px}
.sidebar-box{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:18px}
.sidebar-box h4{margin:0 0 10px}
.tag{display:inline-flex;padding:6px 10px;border-radius:999px;background:var(--muted);color:var(--muted-fg);font-size:13px}
.tag:hover{filter:brightness(.98);color:var(--fg)}
footer{margin-top:64px;border-top:1px solid var(--border);background:var(--card)}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:24px;padding:44px 0}
@media (max-width: 900px){.footer-grid{grid-template-columns:1fr}}
.small{font-size:13px;color:var(--muted-fg)}
.disclaimer{margin-top:22px;padding:14px;border-radius:12px;background:rgba(100,116,139,.10)}
.prose-article h2{margin-top:44px}
.prose-article h3{margin-top:28px}
.prose-article p{margin:0 0 14px}
.prose-article ul, .prose-article ol{margin:0 0 18px 18px}
.prose-article li{margin:0 0 8px}
.prose-article blockquote{margin:18px 0;padding:12px 16px;border-left:4px solid var(--primary);background:rgba(100,116,139,.10);border-radius:0 12px 12px 0}
.toc{position:sticky;top:88px}
.toc-box{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:16px;margin-bottom:18px}
.toc-box h4{margin:0 0 10px}
.toc-box a{display:block;padding:6px 0;color:var(--muted-fg);font-size:14px}
.toc-box a:hover{color:var(--fg)}
.cta{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:18px;border-radius:var(--radius);border:1px solid var(--border);margin:18px 0}
.cta.primary{background:linear-gradient(135deg, rgba(29,78,216,.12), rgba(29,78,216,.03))}
.cta.secondary{background:rgba(29,78,216,.06)}
.cta.inline{background:rgba(100,116,139,.08)}
.cta-title{margin:0;font-size:18px}
.cta-desc{margin:6px 0 0;color:var(--muted-fg)}
.article-header{padding:34px 0 46px;background:linear-gradient(to bottom, rgba(29,78,216,.08), transparent)}
.backlink{display:inline-flex;align-items:center;gap:10px;color:var(--muted-fg);font-weight:600}
.backlink:hover{color:var(--fg)}
.article-title{font-size:38px;line-height:1.15;margin:12px 0}
.article-excerpt{color:var(--muted-fg);font-size:18px;max-width:860px}
hr.sep{border:0;border-top:1px solid var(--border);margin:40px 0}
.scroll-top{position:fixed;right:18px;bottom:18px;display:none}
.scroll-top.show{display:inline-flex}
@media (max-width: 768px){
  .nav{display:none}
  .mobile-toggle{display:flex;gap:10px;align-items:center}
  .mobile-nav.open{display:block}
  h1{font-size:36px}
  .article-title{font-size:32px}
}