/* ZK-F shared site styles */
:root{--ink:#111;--muted:#5f6368;--line:#e6e6e2;--surface:#f7f7f5;--surface2:#efefec;--black:#090909;--green:#18a558;--green-soft:#e9f8ef;--amber:#a86510;--amber-soft:#fff7df;--violet:#6557d7;--violet-soft:#f0edff;--red:#b83838;--red-soft:#fff0f0;--max:1180px;--article:800px;--radius:18px;--shadow:0 18px 55px rgba(0,0,0,.07)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;color:var(--ink);background:#fff;font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;line-height:1.68;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}a{color:inherit}img{max-width:100%;height:auto}.container{width:min(var(--max),calc(100% - 40px));margin:0 auto}.article{width:min(var(--article),100%);margin:0 auto}
/* Shared header — identical markup on every page */
.header{position:sticky;top:0;z-index:1000;background:rgba(255,255,255,.96);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}.nav{min-height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;font-weight:760;letter-spacing:-.02em;min-width:0}.brand-logo{width:38px;height:38px;object-fit:contain;flex:0 0 38px}.brand-title{font-size:1rem;line-height:1.15;white-space:nowrap}.navlinks{display:flex;align-items:center;gap:4px;list-style:none;padding:0;margin:0}.navlinks a{display:block;padding:8px 10px;border-radius:8px;text-decoration:none;color:#454545;font-size:.86rem;font-weight:600;white-space:nowrap}.navlinks a:hover{background:var(--surface);color:#000}
.hero{padding:90px 0 62px;background:linear-gradient(145deg,#fff 25%,#f6f7f5 100%);border-bottom:1px solid var(--line)}.eyebrow{display:inline-flex;align-items:center;gap:8px;padding:5px 9px;border:1px solid #d9ddd9;border-radius:999px;background:#fff;font-size:.75rem;font-weight:760;letter-spacing:.06em;text-transform:uppercase;color:#3e4741}.eyebrow:before{content:"";width:7px;height:7px;border-radius:50%;background:var(--green)}h1,h2,h3{line-height:1.15;letter-spacing:-.025em;margin-top:0}h1{font-size:clamp(2.55rem,6vw,4.8rem);max-width:950px;margin:18px 0 22px}h2{font-size:clamp(1.9rem,4vw,3rem);margin-bottom:16px}h3{font-size:1.25rem;margin-bottom:9px}.dek{font-size:clamp(1.08rem,2vw,1.3rem);max-width:790px;color:#52575b;margin:0 0 22px}.meta{display:flex;gap:16px;flex-wrap:wrap;color:#73777a;font-size:.86rem}.answer{margin-top:34px;background:#0b0b0b;color:#fff;border-radius:var(--radius);padding:25px 28px;box-shadow:var(--shadow)}.answer strong{color:#5be59a}.answer p{margin:0;color:#ececec;font-size:1.06rem}
.toc{padding:26px 0;border-bottom:1px solid var(--line);background:#fff}.toc-inner{display:flex;gap:10px;flex-wrap:wrap}.toc a{font-size:.83rem;text-decoration:none;border:1px solid #d9d9d5;border-radius:999px;padding:6px 10px;color:#4d4d4b}.toc a:hover{border-color:#888;color:#000}section{padding:72px 0}.alt{background:var(--surface)}p{color:#444;margin:0 0 18px}.lead{font-size:1.15rem;color:#5d6265;margin-bottom:28px}.prose h3{margin-top:34px}.prose ul,.prose ol{color:#444;padding-left:24px}.prose li{margin:8px 0}.prose a{text-decoration-color:#b8b8b3;text-underline-offset:3px}.prose a:hover{text-decoration-color:#111}
.callout{border-left:4px solid var(--green);background:var(--green-soft);padding:18px 20px;border-radius:0 12px 12px 0;margin:28px 0}.callout.amber{border-color:var(--amber);background:var(--amber-soft)}.callout.violet{border-color:var(--violet);background:var(--violet-soft)}.callout.red{border-color:var(--red);background:var(--red-soft)}.callout p:last-child{margin-bottom:0}.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:28px 0}.card{border:1px solid var(--line);border-radius:var(--radius);padding:22px;background:#fff}.card p:last-child{margin-bottom:0}.tag{display:inline-block;font-size:.7rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;border-radius:999px;padding:4px 8px;background:var(--surface2);color:#555;margin-bottom:10px}.tag.confirmed{background:var(--green-soft);color:#12683a}.tag.inference{background:var(--amber-soft);color:#86580d}.tag.unknown{background:var(--violet-soft);color:#4d43a3}
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:14px;margin:26px 0}table{border-collapse:collapse;width:100%;min-width:700px;background:#fff}th,td{text-align:left;padding:14px 15px;border-bottom:1px solid var(--line);vertical-align:top;font-size:.9rem}th{background:var(--surface);font-size:.78rem;text-transform:uppercase;letter-spacing:.04em;color:#565b5e}tr:last-child td{border-bottom:0}.formula{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;background:#0d0d0d;color:#f4f4f4;border-radius:14px;padding:18px 20px;overflow:auto;margin:24px 0}
.sources{margin-top:30px;border-top:1px solid var(--line)}.source{display:grid;grid-template-columns:34px 1fr auto;gap:12px;align-items:start;padding:16px 0;border-bottom:1px solid var(--line);text-decoration:none}.source:hover .source-title{text-decoration:underline}.num{color:#929292;font-family:ui-monospace,monospace;font-size:.82rem}.source-title{font-weight:700}.source-meta{display:block;color:#74787b;font-size:.83rem;margin-top:2px}.arrow{color:#999}.related{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.related a{border:1px solid var(--line);border-radius:14px;padding:17px;text-decoration:none;background:#fff}.related a:hover{border-color:#aaa;box-shadow:0 8px 26px rgba(0,0,0,.05)}.related span{display:block;color:#6d7174;font-size:.82rem;margin-top:5px}.faq details{border-bottom:1px solid var(--line);padding:17px 0}.faq summary{font-weight:720;cursor:pointer}.faq p{margin:12px 0 3px}
/* Shared footer — identical markup on every page */
.footer{background:#0b0b0b;color:#fff;padding:56px 0 26px;margin-top:30px}.footer-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(360px,.85fr);gap:64px;align-items:start}.footer-brand-link{display:flex;align-items:center;gap:14px;color:#fff!important;text-decoration:none;font-weight:760;letter-spacing:-.02em;font-size:1.05rem;line-height:1.2}.footer-brand-link img{width:46px;height:46px;object-fit:contain;flex:0 0 46px}.footer-brand p{color:#a9aeaa;max-width:590px;margin:18px 0 0}.footer-brand p a{color:#fff;text-underline-offset:3px}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:11px 22px}.footer-links a{color:#d6d6d6;text-decoration:none;font-size:.88rem}.footer-links a:hover{color:#fff}.footer-bottom{border-top:1px solid #292929;margin-top:38px;padding-top:22px;color:#858a86;font-size:.78rem;display:flex;align-items:center;justify-content:space-between;gap:20px;flex-wrap:wrap}.footer-meta a{color:#aeb3af;text-decoration:none}.footer-meta a:hover{color:#fff}
@media(max-width:980px){.navlinks{gap:1px}.navlinks a{font-size:.8rem;padding:8px 7px}.brand-title{font-size:.92rem}}
@media(max-width:840px){.navlinks{display:none}.brand-title{white-space:normal}.hero{padding-top:62px}.grid,.related,.footer-grid{grid-template-columns:1fr}section{padding:55px 0}.footer-grid{gap:34px}.footer-links{max-width:560px}}
@media(max-width:560px){.container{width:min(var(--max),calc(100% - 28px))}.answer{padding:21px}.hero{padding-bottom:48px}.meta{gap:9px}h1{font-size:2.55rem}.brand-logo{width:34px;height:34px;flex-basis:34px}.brand-title{font-size:.82rem}.footer-brand-link{font-size:.96rem}.footer-brand-link img{width:42px;height:42px;flex-basis:42px}.footer-links{grid-template-columns:1fr}.footer-bottom{align-items:flex-start;flex-direction:column;gap:8px}}