/* Layout: a research-institute reading room. Narrow reading column, wide index grids, a ruled masthead. */
/* Layout: Airo brand — warm paper ground, navy ink, teal accent, Newsreader headlines, dark navy footer. Light-only by design. */
:root{
  --bg:#FFFFFF;
  --surface:#FFFFFF;
  --alt:#F4F4F2;       /* alternating band */
  --ink:#111111;       /* headlines */
  --text:#1C1C1C;
  --muted:#5E5E5E;
  --rule:#E3E3E0;
  --accent:#D71920;    /* signal red */
  --accent-ink:#B0141A;
  --accent-soft:#FCEDEE;
  --accent-mid:#BDBDBD;
  --navy:#111111;      /* footer black */
  --logo:#111111;
  --display:"Archivo", "Helvetica Neue", Arial, sans-serif;
  --body:"Source Sans 3", "Helvetica Neue", Arial, sans-serif;
  --mono:"Archivo", "Helvetica Neue", Arial, sans-serif;
  --measure:68ch;
  --wrap:1200px;
  color-scheme:light;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--body);font-size:1.0625rem;line-height:1.65}
img{max-width:100%;height:auto}
a{color:var(--accent);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:2px}
h1,h2,h3{font-family:var(--display);font-weight:400;line-height:1.15;text-wrap:balance;margin:0;letter-spacing:-.005em;color:var(--ink)}
h1{font-size:clamp(2.1rem,4.6vw,3.5rem)}
h2{font-size:clamp(1.55rem,2.6vw,2.1rem)}
h3{font-size:1.25rem}
p{margin:0}
.wrap{max-width:var(--wrap);margin-inline:auto;padding-inline:clamp(16px,4vw,40px)}
.skip{position:absolute;left:-999px}.skip:focus{left:16px;top:16px;background:var(--surface);padding:8px 12px;z-index:10}
.eyebrow{font-family:var(--body);font-weight:600;font-size:.75rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.eyebrow.accent{color:var(--accent)}

/* Masthead */
.masthead{border-bottom:1px solid var(--rule);box-shadow:0 1px 6px rgba(31,42,55,.06);background:var(--bg);position:sticky;top:env(safe-area-inset-top,0px);z-index:5}
.masthead .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-block:14px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none}
.logo{display:block;height:36px;aspect-ratio:1200/423;background:var(--logo);-webkit-mask:url(logo-mask.png) left center/contain no-repeat;mask:url(logo-mask.png) left center/contain no-repeat}
.foot .logo{background:#FFFFFF;height:34px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.nav{display:flex;gap:4px;flex-wrap:wrap}
.nav a{color:var(--ink);text-decoration:none;font-size:.95rem;padding:6px 10px;border-radius:4px}
.nav a:hover,.nav a[aria-current="page"]{background:var(--accent-soft);color:var(--accent)}
.menu-btn{display:none;background:none;border:1px solid var(--rule);color:var(--ink);border-radius:4px;padding:6px 10px;font:inherit;font-size:.9rem}
@media (max-width:820px){
  .menu-btn{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:100%;background:var(--bg);border-bottom:1px solid var(--rule);flex-direction:column;padding:8px 16px 16px}
  .nav.open{display:flex}
}

/* Hero */
.hero{padding-block:clamp(48px,8vw,96px) clamp(36px,5vw,56px);border-bottom:1px solid var(--rule)}
.hero .wrap{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,1fr);gap:clamp(28px,5vw,64px);align-items:end}
.hero h1 em{font-style:italic;color:var(--accent)}
.hero .lede{font-size:1.2rem;color:var(--muted);max-width:52ch;margin-top:20px}
.btns{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}
.btn{display:inline-block;padding:11px 18px;border-radius:4px;font-weight:500;text-decoration:none;font-size:.98rem}
.btn.primary{background:var(--accent);color:#fff}.btn.primary:hover{background:var(--accent-ink)}
.btn.ghost{border:1px solid var(--accent);color:var(--accent)}
@media (max-width:820px){.hero .wrap{grid-template-columns:1fr}}

/* Answer box (AEO short answer) */
.answer{background:var(--surface);border:1px solid var(--rule);border-left:4px solid var(--accent);padding:20px 22px;border-radius:2px}
.answer .eyebrow{display:block;margin-bottom:8px;color:var(--accent)}
.eyebrow.accent,.crumbs a{color:var(--accent)}
.answer p{font-size:1.06rem}

/* Sections */
.section{padding-block:clamp(48px,7vw,80px);border-bottom:1px solid var(--rule)}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:16px;flex-wrap:wrap;margin-bottom:28px}
.section-head p{color:var(--muted);max-width:56ch;margin-top:8px}
.section-head a{font-size:.95rem;white-space:nowrap}

/* Validity chart */
.scale{background:var(--surface);border:1px solid var(--rule);padding:24px;border-radius:2px}
.scale-row{display:grid;grid-template-columns:minmax(0,11rem) minmax(0,1fr) 3.2rem;gap:14px;align-items:center;padding-block:9px;border-bottom:1px dashed var(--rule)}
.scale-row:last-of-type{border-bottom:0}
.scale-row .lbl{font-size:.95rem}
.bar{height:12px;background:var(--accent-soft);border-radius:1px;position:relative}
.bar i{position:absolute;inset:0 auto 0 0;background:var(--accent);border-radius:1px}
.scale-row .bar i{background:var(--accent-mid)}.scale-row.top .bar i{background:var(--accent)}
.scale-row .val{font-family:var(--mono);font-variant-numeric:tabular-nums;font-size:.92rem;text-align:right}
.axis{display:grid;grid-template-columns:minmax(0,11rem) minmax(0,1fr) 3.2rem;gap:14px;margin-top:6px}
.axis div{display:flex;justify-content:space-between;font-family:var(--mono);font-size:.72rem;color:var(--muted)}
.scale figcaption{font-size:.85rem;color:var(--muted);margin-top:14px}
@media (max-width:560px){.scale-row,.axis{grid-template-columns:minmax(0,7.5rem) minmax(0,1fr) 2.8rem;gap:10px}}

/* Grids & cards */
.grid{display:grid;gap:20px}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
@media (max-width:960px){.g3,.g4{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:620px){.g3,.g4,.g2{grid-template-columns:1fr}}
.card{background:var(--surface);border:1px solid var(--rule);border-top:4px solid var(--accent);border-radius:2px;padding:22px;display:flex;flex-direction:column;gap:10px;min-width:0}
.card h3 a{color:var(--ink);text-decoration:none}
.card h3 a:hover{color:var(--accent)}
.card p{color:var(--muted);font-size:.95rem}
.card .meta{margin-top:auto;padding-top:8px;font-family:var(--mono);font-size:.74rem;color:var(--muted);letter-spacing:.04em}
.finding{font-family:var(--display);font-style:italic;font-size:1.05rem;color:var(--muted);border-top:1px solid var(--rule);padding-top:10px}
.tag{display:inline-block;font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;padding:3px 8px;border-radius:2px;background:var(--accent-soft);color:var(--accent);align-self:flex-start}
.tag.soon{background:#F1ECE3;color:#8A6D3B}
.list{display:flex;flex-direction:column}
.list a.row{display:grid;grid-template-columns:7.5rem minmax(0,1fr);gap:18px;padding-block:16px;border-top:1px solid var(--rule);color:var(--ink);text-decoration:none}
.list a.row:hover h3{color:var(--accent)}
.list .row .eyebrow{padding-top:4px}
.list .row p{color:var(--muted);font-size:.97rem;margin-top:4px}
@media (max-width:560px){.list a.row{grid-template-columns:1fr;gap:4px}}

/* Featured method band */
.method{background:var(--surface);border:1px solid var(--rule);border-radius:2px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.3fr)}
.method > div{padding:clamp(22px,4vw,40px)}
.method > div + div{border-left:1px solid var(--rule)}
.steps{list-style:none;margin:0;padding:0;counter-reset:s}
.steps li{counter-increment:s;display:grid;grid-template-columns:2.2rem minmax(0,1fr);gap:10px;padding-block:12px;border-top:1px solid var(--rule)}
.steps li:first-child{border-top:0}
.steps li::before{content:counter(s,decimal-leading-zero);font-family:var(--mono);font-size:.8rem;color:var(--accent);padding-top:3px}
.steps b{display:block;font-weight:600}
.steps span{color:var(--muted);font-size:.96rem}
@media (max-width:820px){.method{grid-template-columns:1fr}.method > div + div{border-left:0;border-top:1px solid var(--rule)}}

/* FAQ */
.faq details{border-top:1px solid var(--rule);padding-block:14px}
.faq details:last-child{border-bottom:1px solid var(--rule)}
.faq summary{cursor:pointer;font-family:var(--display);font-size:1.2rem;font-weight:400;color:var(--ink);list-style:none;display:flex;justify-content:space-between;gap:16px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-family:var(--mono);color:var(--accent)}
.faq details[open] summary::after{content:"–"}
.faq details p{margin-top:10px;color:var(--ink);max-width:var(--measure)}

/* Newsletter */
.brief{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:28px;align-items:center}
.brief form{display:flex;gap:10px;flex-wrap:wrap}
.brief input{flex:1 1 14rem;min-width:0;padding:11px 12px;border:1px solid var(--rule);border-radius:4px;background:var(--surface);color:var(--ink);font:inherit}
.brief button{padding:11px 18px;border:0;border-radius:4px;background:var(--accent);color:#fff;font:inherit;font-weight:500;cursor:pointer}
.brief .note{font-size:.88rem;color:var(--muted);flex-basis:100%}
@media (max-width:820px){.brief{grid-template-columns:1fr}}

/* Article */
.crumbs{font-size:.86rem;color:var(--muted);padding-top:24px}
.crumbs a{color:var(--muted)}
.article-head{padding-block:28px 32px;border-bottom:1px solid var(--rule)}
.article-head .wrap > *{max-width:860px}
.article-head h1{margin-top:12px}
.article-head .dek{font-size:1.18rem;color:var(--muted);margin-top:16px;max-width:60ch}
.byline{display:flex;flex-wrap:wrap;gap:6px 18px;margin-top:20px;font-family:var(--mono);font-size:.76rem;color:var(--muted);letter-spacing:.03em}
.article{display:grid;grid-template-columns:minmax(0,15rem) minmax(0,1fr);gap:clamp(24px,5vw,64px);padding-block:40px 72px}
.toc{position:sticky;top:90px;align-self:start;font-size:.9rem}
.toc ol{list-style:none;margin:10px 0 0;padding:0;display:flex;flex-direction:column;gap:6px}
.toc a{color:var(--muted);text-decoration:none}
.toc a:hover{color:var(--accent)}
@media (max-width:900px){.article{grid-template-columns:1fr}.toc{position:static;border:1px solid var(--rule);padding:16px;background:var(--surface)}}
.prose{max-width:var(--measure);display:flex;flex-direction:column;gap:18px;min-width:0}
.prose h2{margin-top:22px;scroll-margin-top:90px}
.prose h3{margin-top:8px}
.prose ul,.prose ol{margin:0;padding-left:1.3em;display:flex;flex-direction:column;gap:6px}
.prose blockquote{margin:0;padding:4px 0 4px 18px;border-left:3px solid var(--accent);font-style:italic;font-family:var(--display);font-size:1.15rem}
.prose .keyfindings{background:var(--accent-soft);border-radius:2px;padding:20px 22px}
.prose .keyfindings .eyebrow{color:var(--accent);display:block;margin-bottom:8px}
.table-wrap{overflow-x:auto;border:1px solid var(--rule);border-radius:2px;background:var(--surface)}
table{border-collapse:collapse;width:100%;font-size:.95rem;min-width:520px}
th,td{text-align:left;padding:10px 14px;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-family:var(--mono);font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:500}
td.num{font-family:var(--mono);font-variant-numeric:tabular-nums}
tr:last-child td{border-bottom:0}
.sources{font-size:.9rem;color:var(--muted)}
.sources li{word-break:break-word}
.callout{border:1px solid var(--rule);background:var(--surface);padding:18px 20px;border-radius:2px}
.callout .eyebrow{display:block;margin-bottom:6px;color:var(--accent)}

/* Glossary */
.az{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:24px}
.az a{font-family:var(--mono);font-size:.85rem;padding:4px 9px;border:1px solid var(--rule);border-radius:2px;text-decoration:none}
.gfilter{width:100%;max-width:28rem;padding:11px 12px;border:1px solid var(--rule);border-radius:4px;background:var(--surface);color:var(--ink);font:inherit;margin-bottom:16px}
.terms{display:flex;flex-direction:column}
.term{display:grid;grid-template-columns:minmax(0,15rem) minmax(0,1fr);gap:24px;padding-block:20px;border-top:1px solid var(--rule);scroll-margin-top:90px}
.term dt{font-family:var(--display);font-size:1.3rem;font-weight:400;color:var(--ink)}
.term dd{margin:0;display:flex;flex-direction:column;gap:8px;max-width:var(--measure)}
.term dd b{font-weight:600}
.term dd .more{color:var(--muted);font-size:.97rem}
@media (max-width:700px){.term{grid-template-columns:1fr;gap:6px}}

/* Footer */
.foot{background:var(--navy);color:#C9D1DB;padding-block:56px 40px;font-size:.92rem}
.foot .cols{display:grid;grid-template-columns:minmax(0,1.6fr) repeat(3,minmax(0,1fr));gap:28px}
.foot h4{font-family:var(--body);font-size:.75rem;letter-spacing:.1em;text-transform:uppercase;font-weight:600;margin:0 0 12px;color:#FFFFFF}
.foot ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.foot a{color:#E6EAEF;text-decoration:none}
.foot a:hover{color:#FFFFFF;text-decoration:underline}
.foot .base{margin-top:40px;padding-top:20px;border-top:1px solid rgba(255,255,255,.12);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;font-size:.84rem;color:#AEB7C2}
@media (max-width:820px){.foot .cols{grid-template-columns:1fr 1fr}}
/* Newsletter band (dark, sits above footer) */
.brief-band{background:var(--navy);color:#C9D1DB;padding-block:64px 48px;border-bottom:1px solid rgba(255,255,255,.12);text-align:center}
.brief-band h2{color:#FFFFFF}
.brief-band p.sub{max-width:46ch;margin:12px auto 0}
.brief-band form{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;max-width:520px;margin:28px auto 0}
.brief-band input{flex:1 1 16rem;min-width:0;padding:12px 14px;border:1px solid rgba(255,255,255,.18);border-radius:4px;background:rgba(255,255,255,.08);color:#FFFFFF;font:inherit}
.brief-band input::placeholder{color:#9AA5B1}
.brief-band button{padding:12px 20px;border:0;border-radius:4px;background:var(--accent);color:#FFFFFF;font:inherit;font-weight:600;cursor:pointer}
.brief-band .note{flex-basis:100%;font-size:.84rem;color:#9AA5B1;margin-top:4px}
.brief-band label{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* What is behavior hiring */
.explain-head{margin-bottom:24px}
.explain-cols{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:clamp(24px,4vw,48px);align-items:start}
.explain-cols .prose{max-width:none}
.lead-p{font-size:1.15rem;color:var(--ink)}
.callout.ai{border-top:4px solid var(--accent);display:flex;flex-direction:column;gap:12px;padding:22px 24px}
@media (max-width:860px){.explain-cols{grid-template-columns:1fr}}

/* Topic filter */
.filterbar{border-bottom:1px solid var(--rule);padding-block:16px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{font:inherit;font-size:.85rem;padding:7px 14px;border:1px solid var(--rule);border-radius:3px;background:var(--surface);color:var(--text);cursor:pointer}
.chip:hover{border-color:var(--accent);color:var(--accent)}
.chip[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:#FFFFFF}
.fitem{display:flex;min-width:0}.fitem>.card{flex:1}
.fempty{text-align:center;color:var(--muted);padding-block:24px}
[hidden]{display:none!important}

.filters{display:flex;flex-direction:column;gap:10px}
.tags{display:flex;gap:6px;flex-wrap:wrap}
.tag.stage{background:#F1ECE3;color:#6B5A3E}
.ritem{display:flex;min-width:0}.ritem>.card{flex:1}
.rcount{color:var(--muted);font-size:.9rem;margin-bottom:16px}

/* ===== Red / white / black rebrand overrides ===== */
body{font-size:1.09rem}
h1,h2,h3{font-family:var(--display);font-weight:800;letter-spacing:-.02em;color:var(--ink)}
h1{font-size:clamp(2.3rem,5vw,3.9rem);line-height:1.04}
h2{font-size:clamp(1.6rem,2.8vw,2.3rem)}
h3{font-weight:700;letter-spacing:-.01em}
.eyebrow{font-family:var(--display);font-weight:700;letter-spacing:.1em;color:var(--accent)}
.hero h1 em{font-style:normal;color:var(--accent)}
.masthead{background:#FFFFFF;box-shadow:none;border-bottom:1px solid var(--rule)}
.nav a{font-family:var(--display);font-weight:600;font-size:.95rem;border-radius:0}
.nav a:hover,.nav a[aria-current="page"]{background:transparent;color:var(--accent);box-shadow:inset 0 -3px 0 var(--accent)}
.logo{display:flex;align-items:center;gap:7px;height:auto;aspect-ratio:auto;background:none;-webkit-mask:none;mask:none}
.logo i{display:block;height:38px}
.logo .lg-icon{aspect-ratio:99/120;background:var(--accent);-webkit-mask:url(icon-mask.png) center/contain no-repeat;mask:url(icon-mask.png) center/contain no-repeat}
.logo .lg-word{height:36px;margin-top:1px;aspect-ratio:194/100;background:var(--ink);-webkit-mask:url(word-mask.png) center/contain no-repeat;mask:url(word-mask.png) center/contain no-repeat}
.foot .logo{background:none}
.foot .logo .lg-word{background:#FFFFFF}
.btn{font-family:var(--display);font-weight:700;border-radius:2px}
.btn.primary{background:var(--accent);color:#FFFFFF}.btn.primary:hover{background:var(--accent-ink)}
.btn.ghost{border:2px solid var(--ink);color:var(--ink)}
.hero{background:#FFFFFF;border-bottom:0}
.section{border-bottom:0}
main > .section:nth-of-type(even){background:var(--alt)}
.card{border:1px solid var(--rule);border-top:3px solid var(--accent);border-radius:0}
.card h3{font-size:1.2rem}
.finding{font-family:var(--body);font-style:normal;color:var(--text);border-top:1px solid var(--rule)}
.tag{font-family:var(--display);font-weight:700;background:var(--accent-soft);color:var(--accent);border-radius:0}
.tag.stage,.tag.soon{background:#EFEFED;color:#3A3A3A}
.answer{border-left:4px solid var(--accent);border-radius:0}
.answer .eyebrow{color:var(--accent)}
.lead-p{font-size:1.2rem;color:var(--ink)}
.callout.ai{border-top:4px solid var(--accent);background:#FFFFFF}
.scale{border-radius:0}
.scale-row .bar{background:#EDEDEB}
.scale-row .bar i{background:#9A9A9A}
.scale-row.top .bar i{background:var(--accent)}
.chip{font-family:var(--display);font-weight:600;border-radius:999px;border:1px solid #CFCFCB}
.chip:hover{border-color:var(--ink);color:var(--ink)}
.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:#FFFFFF}
.faq summary{font-family:var(--display);font-weight:700;font-size:1.12rem}
.faq summary::after{color:var(--accent);font-weight:700}
.term dt{font-family:var(--display);font-weight:700;font-size:1.15rem}
.prose blockquote{border-left:4px solid var(--accent);font-family:var(--display);font-weight:700;font-style:normal;font-size:1.3rem;line-height:1.3}
.prose .keyfindings{background:var(--alt);border-left:4px solid var(--accent);border-radius:0}
.prose .keyfindings .eyebrow{color:var(--accent)}
.article-head{background:var(--alt);border-bottom:0}
.crumbs{padding-block:0;background:var(--alt);padding-top:20px}
.byline{font-family:var(--body)}
.brief-band{background:var(--accent);color:#FFFFFF;border-bottom:0}
.brief-band h2{color:#FFFFFF}
.brief-band p.sub{color:#FFE9EA}
.brief-band input{background:#FFFFFF;color:var(--ink);border:0}
.brief-band input::placeholder{color:#7A7A7A}
.brief-band button{background:var(--ink);color:#FFFFFF;font-family:var(--display);font-weight:700}
.brief-band .note{color:#FFE9EA}
.foot{background:#111111}
.foot .base{border-top-color:rgba(255,255,255,.14)}
a{color:var(--accent)}
.card h3 a:hover,.list a.row:hover h3{color:var(--accent)}

.lede-p{font-size:1.2rem;line-height:1.6;color:var(--ink);font-family:var(--body)}
.crumbs{box-shadow:0 0 0 100vmax var(--alt);clip-path:inset(0 -100vmax)}