:root{--bg:#fff;--fg:#1d1d1f;--muted:#6b6b72;--line:#e3e3e8;--accent:#1d4ed8;--bar:#f7f7f9}
@media (prefers-color-scheme:dark){:root{--bg:#141416;--fg:#ececf0;--muted:#9a9aa5;--line:#2c2c33;--accent:#8ab4ff;--bar:#1b1b1f}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--fg);font:18px/1.7 Georgia,"Times New Roman",serif}
.wrap{max-width:46rem;margin:0 auto;padding:0 16px}
a{color:var(--accent)}
.site-header{border-bottom:1px solid var(--line);background:var(--bar);font-family:system-ui,-apple-system,"Segoe UI",sans-serif}
.site-header>.wrap{display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:8px 24px;padding-top:14px;padding-bottom:14px}
.site-title{font-weight:700;color:var(--fg);text-decoration:none;font-size:1.05rem}
.top-nav a{margin-left:20px;text-decoration:none;color:var(--muted);font-size:.95rem;padding-bottom:2px}
.top-nav a:first-child{margin-left:0}
.top-nav a.active,.top-nav a:hover{color:var(--fg);border-bottom:2px solid var(--accent)}
.sub-nav{border-top:1px solid var(--line)}
.sub-nav .wrap{display:flex;flex-wrap:wrap;gap:4px 18px;padding-top:8px;padding-bottom:8px}
.sub-nav a{font-size:.85rem;text-decoration:none;color:var(--muted)}
.sub-nav a.active,.sub-nav a:hover{color:var(--fg);font-weight:600}
.content{padding-top:32px;padding-bottom:48px}
h1{font:700 2rem/1.25 system-ui,-apple-system,"Segoe UI",sans-serif;margin:.2em 0 .8em}
h2,h3{font-family:system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.3;margin-top:2em}
blockquote{margin:1.5em 0;padding-left:1em;border-left:3px solid var(--line);color:var(--muted)}
.crumb{font:.85rem system-ui,sans-serif;color:var(--muted);margin:0}
.crumb a{color:var(--muted)}
.section-list{padding-left:1.4em}
.section-list li{margin:.6em 0}
.section-list li span{display:block;color:var(--muted);font-size:.9rem;line-height:1.5}
.pager{display:flex;justify-content:space-between;gap:16px;max-width:46rem;margin:0 auto;padding:16px 16px 48px;font:.95rem system-ui,sans-serif;border-top:1px solid var(--line)}
.pager a{text-decoration:none}
.site-footer{border-top:1px solid var(--line);padding:20px 0;color:var(--muted);font:.85rem system-ui,sans-serif}