:root{--bg:#fbfcfb;--paper:#fff;--ink:#1d2621;--muted:#5b6660;--line:#e1e7e3;--soft:#f1f5f2;--accent:#2f7d4f;--accent-d:#22603b;--accent-l:#e5f2ea;--warn:#fdf4e3;--warn-l:#e9c46a;--hh:64px;--r:10px}
*{box-sizing:border-box}html{scroll-padding-top:calc(var(--hh) + 16px);-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.7 system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif}
img{max-width:100%;height:auto}a{color:var(--accent-d)}a:hover{color:var(--accent)}
.wrap{max-width:1140px;margin:0 auto;padding:0 20px}.wrap.narrow{max-width:780px}
.skip{position:absolute;left:-999px;top:0;background:#000;color:#fff;padding:8px 12px;z-index:100}.skip:focus{left:8px}
/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line);backdrop-filter:saturate(1.4) blur(6px)}
.hdr{display:flex;align-items:center;gap:20px;min-height:var(--hh)}
.brand{display:flex;align-items:center;gap:9px;font-weight:800;font-size:1.15rem;color:var(--ink);text-decoration:none;letter-spacing:-.01em;white-space:nowrap}
.main-nav ul{display:flex;gap:4px;list-style:none;margin:0;padding:0}
.main-nav a{display:block;padding:8px 11px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:.95rem;font-weight:500}
.main-nav a:hover,.main-nav a[aria-current]{background:var(--accent-l);color:var(--accent-d)}
.hdr-right{margin-left:auto;display:flex;align-items:center;gap:8px}
.btn{display:inline-block;border-radius:999px;padding:9px 18px;font-weight:700;text-decoration:none;font-size:.93rem;line-height:1.2;text-align:center}
.btn-cta{background:var(--accent);color:#fff}.btn-cta:hover{background:var(--accent-d);color:#fff}
.nav-toggle{display:none;width:42px;height:42px;border:1px solid var(--line);background:#fff;border-radius:8px;padding:10px 9px;cursor:pointer}
.nav-toggle span{display:block;height:2px;background:var(--ink);margin:4px 0;border-radius:2px}
@media (max-width:960px){
 .nav-toggle{display:block}
 .main-nav{position:absolute;left:0;right:0;top:100%;background:#fff;border-bottom:1px solid var(--line);display:none;box-shadow:0 8px 20px rgba(0,0,0,.06)}
 .main-nav.open{display:block}.main-nav ul{flex-direction:column;padding:8px 14px 14px}.main-nav a{padding:12px}
}
.btn-cta{white-space:nowrap}
@media (max-width:420px){.wrap.hdr{padding:0 12px}.brand{gap:6px}.brand span{font-size:.98rem}.brand img{width:24px;height:24px}.btn-cta{padding:8px 11px;font-size:.8rem}.hdr{gap:8px}.hdr-right{gap:6px}.nav-toggle{width:38px;height:38px;padding:9px 8px}}
@media (max-width:350px){.brand span{display:none}}
/* crumbs + heads */
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;padding:0;margin:20px 0 0;font-size:.86rem;color:var(--muted)}
.crumbs li+li::before{content:"›";margin-right:6px;color:#9aa59f}.crumbs a{color:var(--muted)}
.page-head{text-align:center;margin:26px 0 22px}
h1{font-size:clamp(1.85rem,4.4vw,2.6rem);line-height:1.2;letter-spacing:-.02em;margin:0 0 10px}
.sub{color:var(--muted);font-size:1.08rem;max-width:680px;margin:0 auto}.byline{color:var(--muted);font-size:.9rem;margin:0}
/* toc */
.toc{background:var(--soft);border:1px solid var(--line);border-radius:var(--r);padding:16px 22px;margin:0 0 30px}
.toc-h{font-weight:700;margin:0 0 6px}.toc ol{margin:0;padding-left:20px;columns:2;column-gap:28px;font-size:.94rem}.toc li{break-inside:avoid;margin:3px 0}
@media (max-width:640px){.toc ol{columns:1}}
/* prose */
.prose h2{font-size:1.6rem;line-height:1.3;margin:2.2em 0 .6em;letter-spacing:-.01em}
.prose h3{font-size:1.24rem;line-height:1.35;margin:1.6em 0 .5em}.prose h4{font-size:1.06rem;margin:1.3em 0 .4em}
.prose p,.prose ul,.prose ol{margin:0 0 1.1em}.prose li{margin:.3em 0}
.prose table{width:100%;border-collapse:collapse;margin:1.2em 0 1.6em;font-size:.95rem;background:#fff;display:block;overflow-x:auto}
.prose th,.prose td{border:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
.prose thead th{background:var(--accent-l);color:var(--accent-d)}.prose tbody tr:nth-child(even){background:#f8faf9}
.keybox{background:var(--accent-l);border-left:4px solid var(--accent);border-radius:var(--r);padding:16px 20px;margin:0 0 1.6em}
.keybox p:first-child{font-weight:700;margin-bottom:.4em}.keybox ul{margin:0;padding-left:20px}
.note{background:var(--warn);border-left:4px solid var(--warn-l);border-radius:var(--r);padding:14px 18px;margin:1.2em 0 1.5em}
.note p:last-child{margin:0}
.faq-item{border:1px solid var(--line);border-radius:var(--r);padding:4px 18px;margin:0 0 12px;background:#fff}
.faq-item h3{font-size:1.08rem;margin:.9em 0 .3em}
.sources{font-size:.9rem;color:var(--muted)}
/* cards */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px;margin:10px 0 30px}
.card{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px 20px;text-decoration:none;color:var(--ink);transition:border-color .15s,box-shadow .15s}
.card:hover{border-color:#b9d6c4;box-shadow:0 6px 18px rgba(30,70,45,.08);color:var(--ink)}
.card h3{font-size:1.08rem;line-height:1.35;margin:0 0 6px}.card p{color:var(--muted);font-size:.93rem;margin:0 0 10px;flex:1}
.card .more{color:var(--accent-d);font-weight:600;font-size:.9rem}
.related{margin-top:40px;border-top:1px solid var(--line);padding-top:10px}.related h2{font-size:1.4rem}
/* home */
.hero{background:linear-gradient(180deg,#eef6f1,#fbfcfb);border-bottom:1px solid var(--line);padding:56px 0 40px;text-align:center}
.hero-links{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-top:22px}
.hero-links a{background:#fff;border:1px solid var(--line);border-radius:999px;padding:7px 15px;text-decoration:none;font-weight:600;font-size:.93rem}
.home-intro{max-width:780px;margin:34px auto 10px}
.hub-block{margin:26px 0}.hub-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap}
.hub-head h2{margin:0;font-size:1.5rem}.hub-lede{color:var(--muted);margin:4px 0 4px}
.hub-body{max-width:780px;margin:10px auto 0}
/* footer */
.site-footer{margin-top:60px;background:#f2f5f3;border-top:1px solid var(--line);padding:36px 0 26px;font-size:.92rem}
.f-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:22px}
.f-h{font-size:.98rem;margin:0 0 8px}.site-footer ul{list-style:none;padding:0;margin:0}.site-footer li{margin:5px 0}
.site-footer a{color:var(--ink);text-decoration:none}.site-footer a:hover{text-decoration:underline}
.f-note{color:var(--muted);margin:26px 0 8px}.f-util,.f-copy{color:var(--muted);margin:4px 0}
/* images */
figure{margin:0}
.hero-fig,.hub-fig{margin:0 0 28px}
.hero-fig img,.hub-fig img{display:block;width:100%;height:auto;max-height:440px;object-fit:cover;border-radius:14px;background:var(--soft)}
.hub-fig{max-width:900px;margin:0 auto 26px}.hub-fig img{max-height:380px}
figcaption{font-size:.78rem;color:var(--muted);margin-top:6px;text-align:right}figcaption a{color:var(--muted)}
.card img{display:block;max-width:none;width:calc(100% + 40px);margin:-18px -20px 14px;height:150px;object-fit:cover;border-radius:12px 12px 0 0;background:var(--soft)}
.card{overflow:hidden}
.hero{text-align:left;padding:44px 0 36px}
.hero-grid{display:grid;grid-template-columns:1.05fr 1fr;gap:36px;align-items:center}
.hero-grid .sub{margin:0}.hero-grid .hero-links{justify-content:flex-start}
.hero .hero-fig{margin:0}.hero .hero-fig img{max-height:380px}
@media (max-width:820px){.hero-grid{grid-template-columns:1fr;gap:22px}.hero{padding:30px 0 26px}}

/* series nav */
.series{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:36px 0 0}
.series a{display:block;border:1px solid var(--line);border-radius:12px;padding:14px 18px;text-decoration:none;color:var(--ink);background:#fff;font-weight:600;line-height:1.35}
.series a:hover{border-color:#b9d6c4;box-shadow:0 6px 18px rgba(30,70,45,.08)}
.series a span{display:block;font-size:.8rem;font-weight:600;color:var(--accent-d);text-transform:uppercase;letter-spacing:.04em;margin-bottom:4px}
.series .next{text-align:right}
@media (max-width:560px){.series{grid-template-columns:1fr}.series .next{text-align:left}}

.dyk{background:var(--soft);border:1px solid var(--line);border-left:4px solid var(--accent-d);border-radius:var(--r);padding:14px 18px;margin:0 0 1.6em}.dyk-h{font-weight:700;color:var(--accent);margin:0 0 .3em!important}.dyk p:last-child{margin:0}
.mid-fig{margin:1.6em 0}.mid-fig img{width:100%;height:auto;max-height:440px;object-fit:cover;background:var(--soft);border-radius:var(--r);display:block}