:root{--ink:#102033;--muted:#607086;--bg:#f7f9fc;--card:#fff;--brand:#635bff;--brand2:#2a235f;--accent:#f2b84b;--line:#dfe5ee;--max:1120px}
*{box-sizing:border-box}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--bg);line-height:1.65}
a{color:var(--brand2)}.wrap{max-width:var(--max);margin:auto;padding:0 22px}.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.header-row{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:72px}.brand{text-decoration:none;font-weight:900;letter-spacing:-.03em;font-size:1.25rem;color:var(--ink)}.brand span{color:var(--brand)}
nav{display:flex;gap:16px;flex-wrap:wrap}nav a{text-decoration:none;font-weight:650;font-size:.9rem;color:#334155}.hero{padding:72px 0 48px;background:linear-gradient(145deg,#fff,#f0efff)}
.eyebrow{text-transform:uppercase;letter-spacing:.12em;font-weight:800;font-size:.78rem;color:var(--brand)}h1{font-size:clamp(2.25rem,5vw,4.5rem);line-height:1.02;letter-spacing:-.055em;margin:.25em 0}.lede{font-size:1.2rem;max-width:760px;color:#46566b}
.btn{display:inline-block;background:var(--brand);color:#fff;text-decoration:none;padding:14px 20px;border-radius:12px;font-weight:800;box-shadow:0 8px 20px rgba(99,91,255,.2)}.btn:hover{filter:brightness(.95)}
.btn.secondary{background:#fff;color:var(--brand2);border:1px solid var(--line);box-shadow:none}.cta-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}
main.article{max-width:820px;margin:0 auto;padding:42px 22px 72px}.crumbs{font-size:.86rem;color:var(--muted);margin-bottom:24px}.crumbs a{color:var(--muted)}
h2{font-size:1.8rem;line-height:1.2;letter-spacing:-.025em;margin-top:2em}h3{font-size:1.25rem;margin-top:1.6em}.note,.cta-box,.disclosure{border:1px solid var(--line);background:#fff;border-radius:16px;padding:20px;margin:28px 0}.cta-box{background:var(--brand2);color:#fff}.cta-box a{color:#fff}.cta-box .btn{background:#fff;color:var(--brand2)}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:22px}.card h3{margin-top:0}.card a{text-decoration:none}.section{padding:54px 0}.section h2{margin-top:0}.kicker{font-weight:800;color:var(--brand)}
footer{background:#0f172a;color:#cbd5e1;padding:44px 0}footer a{color:#e2e8f0}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:30px}
.small{font-size:.86rem;color:var(--muted)}footer .small{color:#94a3b8}.checklist li{margin:.55em 0}.toc{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px 22px}.toc a{text-decoration:none}
@media(max-width:850px){nav{display:none}.grid,.footer-grid{grid-template-columns:1fr}.hero{padding-top:48px}.site-header{position:static}}

/* Responsive reading layout and optional contextual sidebar */
.reading-layout{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:36px;align-items:start;max-width:1160px;margin:auto;padding:0 22px}
.reading-layout main.article{max-width:none;width:100%;min-width:0;padding-left:0;padding-right:0}
.article-sidebar{position:sticky;top:92px;margin-top:48px}
.side-panel{background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px;margin-bottom:18px}
.side-panel h2{font-size:1.18rem;margin:0 0 12px}.side-panel p{font-size:.93rem}
.side-panel .btn{display:block;text-align:center;font-size:.9rem;padding:12px}
.header-cta{white-space:nowrap;font-size:.85rem;padding:10px 14px}
@media(max-width:1000px){.reading-layout{grid-template-columns:minmax(0,1fr)}.article-sidebar{position:static;margin:0 0 35px}.header-row{flex-wrap:wrap;padding-top:12px;padding-bottom:12px}nav{order:3;width:100%;justify-content:center}.header-cta{margin-left:auto}}
@media(max-width:850px){nav{display:flex;gap:10px;overflow-x:auto;flex-wrap:nowrap;justify-content:flex-start}nav a{white-space:nowrap;font-size:.8rem}.header-cta{font-size:.78rem;padding:9px 11px}}

/* Header: single-row desktop, accessible collapsible menu on compact screens. */
.site-header .header-row{display:flex;flex-wrap:nowrap;align-items:center;gap:clamp(10px,1.3vw,20px);min-height:72px;padding-top:0;padding-bottom:0}
.site-header .brand{white-space:nowrap;flex:0 0 auto;font-size:clamp(1rem,1.55vw,1.25rem)}
.site-header .header-nav{display:flex;flex:1 1 auto;min-width:0;align-items:center;justify-content:center;gap:clamp(8px,1vw,16px);flex-wrap:nowrap;width:auto;order:initial}
.site-header .header-nav a{white-space:nowrap;font-size:clamp(.73rem,.82vw,.9rem)}
.site-header .header-cta{flex:0 0 auto;white-space:nowrap;margin-left:0}
.site-header .mobile-menu{display:none}
@media(max-width:1250px){
 .site-header .header-row{min-height:68px}
 .site-header .header-nav{display:none}
 .site-header .header-cta{margin-left:auto}
 .site-header .mobile-menu{display:block;position:relative;flex:0 0 auto}
 .site-header .mobile-menu summary{cursor:pointer;list-style:none;border:1px solid var(--line);border-radius:10px;padding:9px 12px;font-weight:750;background:#fff}
 .site-header .mobile-menu summary::-webkit-details-marker{display:none}
 .site-header .mobile-menu summary::after{content:" ▾"}
 .site-header .mobile-menu[open] summary::after{content:" ▴"}
 .site-header .mobile-nav{display:flex;flex-direction:column;position:absolute;right:0;top:calc(100% + 8px);width:min(300px,calc(100vw - 32px));padding:10px;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 15px 40px rgba(16,32,51,.15);z-index:30;gap:0}
 .site-header .mobile-nav a{display:block;padding:9px 12px;text-decoration:none;color:var(--ink);font-weight:650;border-radius:8px}
 .site-header .mobile-nav a:hover,.site-header .mobile-nav a:focus-visible{background:var(--bg)}
}
@media(max-width:480px){
 .site-header .header-row{gap:7px}
 .site-header .brand{font-size:clamp(.83rem,3.4vw,1rem);letter-spacing:-.04em}
 .site-header .header-cta{font-size:.7rem;padding:8px 9px;border-radius:9px}
 .site-header .mobile-menu summary{font-size:.75rem;padding:8px}
}
@media(max-width:350px){
 .site-header .header-row{gap:5px}
 .site-header .brand{font-size:.76rem}
 .site-header .header-cta{font-size:.64rem;padding:7px}
 .site-header .mobile-menu summary{font-size:.7rem;padding:7px}
}