:root{--navy:#0b2545;--blue:#1f5fa8;--soft:#eaf1f9;--grey:#f3f5f8;--line:#d9dfe7;--text:#1d2733;--muted:#5a6675;--gold:#b08a3e}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font:400 1rem/1.7 Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;color:var(--text);background:#fff}
a{color:var(--blue)}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--gold);outline-offset:2px}
.wrap{max-width:1120px;margin:0 auto;padding:0 20px}.narrow{max-width:760px}
.skip{position:absolute;left:-999px}.skip:focus{left:10px;top:10px;background:#fff;padding:8px;z-index:99}.sr{position:absolute;left:-999px}
h1,h2,h3{color:var(--navy);line-height:1.25;margin:0 0 .6em}h1{font-size:clamp(1.8rem,4vw,2.6rem);font-weight:700}h2{font-size:1.5rem;font-weight:600;margin-top:1.6em}h3{font-size:1.1rem}
.site-header{position:sticky;top:0;background:#fff;border-bottom:1px solid var(--line);z-index:20}
.bar{display:flex;align-items:center;justify-content:space-between;min-height:68px}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none}.logo-mark{width:34px;height:34px;border-radius:6px;background:var(--navy);color:#fff;display:grid;place-items:center;font-weight:700}
.logo-text{font-size:1.4rem;font-weight:700;color:var(--navy);letter-spacing:-.01em;margin:0}.logo-text.light{color:#fff}
.main-nav ul{display:flex;gap:2px;list-style:none;margin:0;padding:0}.main-nav a{display:block;padding:8px 11px;color:var(--text);text-decoration:none;font-size:.93rem;font-weight:500;border-radius:4px}
.main-nav a:hover{background:var(--grey)}.main-nav a[aria-current]{color:var(--navy);box-shadow:inset 0 -2px var(--gold)}
.menu-btn{display:none;background:none;border:1px solid var(--line);border-radius:6px;padding:10px;cursor:pointer}.menu-btn i{display:block;width:22px;height:2px;background:var(--navy);margin:4px 0}
.hero{background:var(--navy);color:#fff;padding:64px 0}.hero h1{color:#fff}.hero-in{display:grid;grid-template-columns:1.4fr 1fr;gap:40px;align-items:center}
.lead{font-size:1.1rem;color:var(--muted)}.hero .lead{color:#d4deec}
.hero-box{background:rgba(255,255,255,.08);border-left:3px solid var(--gold);padding:22px}.hero-box h2{color:#fff;font-size:1.15rem;margin-top:0}.hero-box p{margin:0;color:#d4deec}
.btn{display:inline-block;background:var(--blue);color:#fff;border:0;padding:11px 20px;border-radius:6px;font:600 .95rem Inter,sans-serif;text-decoration:none;cursor:pointer}.hero .btn{background:#fff;color:var(--navy)}.btn.ghost,.hero .btn.ghost{background:transparent;color:#fff;border:1px solid #8fa5c2}
.sec{padding:56px 0}.alt{background:var(--grey)}.sec h2:first-child{margin-top:0}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.card{display:block;background:#fff;border:1px solid var(--line);border-top:3px solid var(--navy);padding:22px;border-radius:4px;text-decoration:none;color:var(--text)}.card p{color:var(--muted);margin:0 0 10px}.card span{color:var(--blue);font-weight:600;font-size:.9rem}.card:hover{border-top-color:var(--gold)}.card.plain{border-top-color:var(--line)}
.two{display:grid;grid-template-columns:1fr 1fr;gap:40px}.ticks{padding-left:1.1em}
.tw{overflow-x:auto;margin:1em 0}table{border-collapse:collapse;width:100%;font-size:.95rem}th,td{text-align:left;padding:10px 12px;border:1px solid var(--line);vertical-align:top}th{background:var(--soft);color:var(--navy)}
.crumbs{font-size:.88rem;color:var(--muted);padding:16px 0 0}.crumbs a{text-decoration:none}
.article-wrap{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:48px;padding-top:16px;padding-bottom:56px}
.article-wrap section{scroll-margin-top:84px}article p,article li,.page-wrap p,.page-wrap li{max-width:72ch}
.meta{font-size:.88rem;color:var(--muted)}.info{background:var(--soft);border-left:4px solid var(--blue);padding:14px 18px;margin:1.2em 0;border-radius:0 4px 4px 0}.info.warn{background:#fff7e6;border-color:var(--gold)}
.toc{border:1px solid var(--line);padding:6px 22px 14px;margin:1.5em 0;background:var(--grey)}.toc h2{font-size:1.05rem;margin:.8em 0 .4em}.toc ol{margin:0;padding-left:1.2em}
.formula{background:var(--grey);padding:12px 16px;font-weight:600;color:var(--navy);overflow-x:auto}
details{border:1px solid var(--line);border-radius:4px;margin:8px 0}summary{padding:12px 16px;cursor:pointer;font-weight:600;color:var(--navy)}details p{margin:0;padding:0 16px 14px}
.disclaimer{border:1px solid var(--line);background:var(--grey);padding:6px 20px 14px;margin-top:2.5em;font-size:.9rem;color:var(--muted)}.disclaimer h2{font-size:1rem;margin-top:.8em}
.side{align-self:start;position:sticky;top:88px}.box{border:1px solid var(--line);padding:6px 20px 16px;border-radius:4px;margin-top:1.2em}.box h2{font-size:1.05rem}.box ul{padding-left:1.1em;margin:0}.box li{margin-bottom:8px}
.page-wrap{padding-top:32px;padding-bottom:56px}
form label{display:block;font-weight:600;margin:14px 0 4px;color:var(--navy)}input,textarea{width:100%;padding:11px 12px;border:1px solid #b5bfcc;border-radius:4px;font:inherit}.form-msg{min-height:1.5em;font-weight:500}.form-msg.err{color:#a12c2c}.form-msg.ok{color:#1c6b3a}
.site-footer{background:var(--navy);color:#c9d5e6;padding:44px 0 24px;font-size:.93rem}.site-footer h2{color:#fff;font-size:1rem;margin:0 0 10px}.site-footer ul{list-style:none;padding:0;margin:0}.site-footer li{margin-bottom:6px}.site-footer a{color:#c9d5e6}
.grid4{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:32px}.disc{border-top:1px solid #2c4568;margin-top:28px;padding-top:18px;font-size:.82rem;color:#aebbd0}.copy{font-size:.85rem}
@media(max-width:900px){.article-wrap,.two,.hero-in{grid-template-columns:1fr}.side{position:static}.cards{grid-template-columns:1fr 1fr}.grid4{grid-template-columns:1fr 1fr}}
@media(max-width:820px){.menu-btn{display:block}.main-nav{display:none;position:absolute;left:0;right:0;top:100%;background:#fff;border-bottom:1px solid var(--line);padding:8px 20px 14px}.main-nav.open{display:block}.main-nav ul{flex-direction:column}}
@media(max-width:560px){.cards,.grid4{grid-template-columns:1fr}.hero{padding:44px 0}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}