:root{color-scheme:light;--bg:#fff;--fg:#17202a;--muted:#5b6673;--brand:#0b5fff;--brand-fg:#fff;--card:#f4f7fb;--line:#e1e7ef;--note:#fff8e1}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.7 system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif}
.wrap{max-width:1160px;margin:0 auto;padding:0 16px}
.layout main{max-width:820px;min-width:0}
.bn{display:block;margin:1.5rem auto;text-align:center}
.bn img{max-width:100%;height:auto;border-radius:6px;border:1px solid var(--line);vertical-align:top}
.side .bn{margin-top:1.5rem}
@media (min-width:1100px){.layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:2.5rem}.side{position:sticky;top:5rem;align-self:start}}
a{color:var(--brand)}
h1{font-size:2rem;line-height:1.25;margin:1.2rem 0 .5rem}
h2{font-size:1.4rem;line-height:1.3;margin:2rem 0 .6rem}
h3{font-size:1.1rem;margin:1.2rem 0 .2rem}
.top{border-bottom:1px solid var(--line);background:var(--bg);position:sticky;top:0;z-index:5}
.top .wrap{display:flex;flex-direction:column;gap:.2rem;padding-top:.6rem;padding-bottom:.6rem}
.brand{font-weight:800;font-size:1.15rem;text-decoration:none;color:var(--fg)}
.cats{display:flex;gap:.9rem;overflow-x:auto;white-space:nowrap;font-size:.9rem;scrollbar-width:thin}
.cats a{text-decoration:none;color:var(--muted)}
.cats a:hover{color:var(--brand)}
.crumbs,.meta,.small{color:var(--muted);font-size:.9rem}
.lead{font-size:1.15rem;color:var(--muted)}
.hero{padding:1.5rem 0 .5rem}
.btn{display:inline-block;background:var(--brand);color:var(--brand-fg);padding:.7rem 1.2rem;border-radius:10px;text-decoration:none;font-weight:700}
.btn:hover{opacity:.9}
.toc{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:.8rem 1.2rem;margin:1rem 0}
.toc ol{margin:.4rem 0 0;padding-left:1.2rem}
.note{background:var(--note);border-left:4px solid #f5b400;padding:.7rem 1rem;border-radius:6px;margin:1rem 0}
.cta{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:1rem 1.4rem;margin:2.2rem 0}
.cta h2{margin-top:.2rem}
.cards{list-style:none;padding:0;display:grid;gap:.8rem}
.cards a{display:block;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:.9rem 1.1rem;text-decoration:none;color:var(--fg)}
.cards a:hover{border-color:var(--brand)}
.cards span{display:block;color:var(--muted);font-size:.92rem;margin-top:.2rem}
.alist{padding-left:1.2rem}
.alist li{margin:.25rem 0}
.hsec{margin:1.5rem 0}
.hsec h2 a{text-decoration:none;color:var(--fg)}
.foot{border-top:1px solid var(--line);margin-top:3rem;padding:1.5rem 0;color:var(--muted)}
@media (min-width:700px){.top .wrap{flex-direction:row;align-items:center;justify-content:space-between;gap:1rem}.cards{grid-template-columns:1fr 1fr}h1{font-size:2.3rem}}