/* Quantum Arbor Learn. Shared stylesheet for every page. */
@font-face{font-family:Inter;font-style:normal;font-weight:400;font-display:swap;src:url(../fonts/inter-latin-400-normal.woff2) format("woff2")}
@font-face{font-family:Inter;font-style:normal;font-weight:600;font-display:swap;src:url(../fonts/inter-latin-600-normal.woff2) format("woff2")}
@font-face{font-family:Inter;font-style:normal;font-weight:700;font-display:swap;src:url(../fonts/inter-latin-700-normal.woff2) format("woff2")}
@font-face{font-family:Sora;font-style:normal;font-weight:600;font-display:swap;src:url(../fonts/sora-latin-600-normal.woff2) format("woff2")}
@font-face{font-family:Sora;font-style:normal;font-weight:700;font-display:swap;src:url(../fonts/sora-latin-700-normal.woff2) format("woff2")}

:root{
  --bg:#FFFFFF;--ink:#11252B;--line:#DCE6EA;--muted:#4F636C;--teal:#12707F;--teal-dark:#0C5561;--tint:#EEF8FB;--soft:#F4F7F8;--light:#4F97A3;
  --focus:#0B57D0;--err:#B3261E;--ok:#146C2E;
  --max:1120px;--read:720px;--r:12px;
}
*,*:before,*:after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:88px}
body{margin:0;background:var(--bg);color:var(--ink);font:400 1.0625rem/1.65 Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
img,svg{max-width:100%;height:auto}
a{color:var(--teal);text-underline-offset:3px}
a:hover{color:var(--teal-dark)}
:focus-visible{outline:3px solid var(--focus);outline-offset:3px;border-radius:4px}
h1,h2,h3{font-family:Sora,Inter,sans-serif;line-height:1.2;letter-spacing:-.01em;margin:0 0 .5em}
h1{font-size:clamp(2rem,5vw,3.1rem)}
h2{font-size:clamp(1.5rem,3.2vw,2rem);margin-top:0}
h3{font-size:1.15rem}
p{margin:0 0 1em}
.sr-only{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip{position:absolute;left:12px;top:-60px;background:var(--ink);color:#fff;padding:10px 16px;border-radius:8px;z-index:100;font-weight:600}
.skip:focus{top:12px;color:#fff}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}
.read{max-width:var(--read)}
.muted{color:var(--muted)}
.small{font-size:.9rem}
.eyebrow{font-size:.78rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--teal);margin:0 0 .6em}

/* header */
.site-header{position:sticky;top:0;z-index:40;background:rgba(255,255,255,.96);border-bottom:1px solid var(--line)}
@supports (backdrop-filter:blur(6px)){.site-header{background:rgba(255,255,255,.88);backdrop-filter:blur(6px)}}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:68px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand img{height:20px;width:auto;display:block}
.brand span{font-size:.8rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--teal);border-left:1px solid var(--line);padding-left:10px}
.nav{display:flex;align-items:center;gap:6px;flex-wrap:wrap}
.nav a{text-decoration:none;color:var(--ink);font-weight:600;font-size:.95rem;padding:8px 12px;border-radius:999px}
.nav a:hover{background:var(--soft)}
.nav a[aria-current="page"]{background:var(--tint);color:var(--teal-dark)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 20px;border-radius:999px;border:2px solid var(--teal);background:var(--teal);color:#fff;font:600 1rem/1.2 Inter,sans-serif;text-decoration:none;cursor:pointer}
.btn:hover{background:var(--teal-dark);border-color:var(--teal-dark);color:#fff}
.btn.ghost{background:transparent;color:var(--teal-dark)}
.btn.ghost:hover{background:var(--tint);color:var(--teal-dark)}
.btn[disabled]{opacity:.6;cursor:wait}
.nav .btn{padding:8px 16px;min-height:40px;font-size:.95rem;color:#fff}
@media (max-width:760px){.nav a.hide-sm{display:none}.brand span{display:none}}

/* hero */
.hero{padding:56px 0 40px;border-bottom:1px solid var(--line)}
.hero .lead{font-size:1.2rem;color:var(--muted);max-width:680px}
.hero .actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}
.byline{display:flex;align-items:center;gap:12px;margin-top:26px;font-size:.95rem}
.byline img{width:48px;height:48px;border-radius:50%}
.byline b{display:block}

/* layout */
.section{padding:56px 0;border-bottom:1px solid var(--line)}
.section:last-of-type{border-bottom:0}
.grid2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}
.grid3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
@media (max-width:860px){.grid3{grid-template-columns:1fr 1fr}}
@media (max-width:640px){.grid2,.grid3{grid-template-columns:1fr}}
.card{border:1px solid var(--line);border-radius:var(--r);padding:20px;background:#fff}
.card.tint{background:var(--tint);border-color:transparent}
.card h3{margin-bottom:.35em}
.card p:last-child{margin-bottom:0}

/* takeaways + toc */
.takeaways{background:var(--tint);border-radius:var(--r);padding:22px 24px;margin:0}
.takeaways h2{font-size:1.2rem}
.takeaways ul{margin:0;padding-left:1.2em}
.takeaways li{margin-bottom:.4em}
.toc{border:1px solid var(--line);border-radius:var(--r);padding:18px 22px}
.toc h2{font-size:1.05rem;margin-bottom:.6em}
.toc ol{margin:0;padding-left:1.3em;columns:2;column-gap:28px}
.toc li{margin-bottom:.35em;break-inside:avoid}
@media (max-width:640px){.toc ol{columns:1}}

/* glossary */
.gloss{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 28px;margin:0}
@media (max-width:700px){.gloss{grid-template-columns:1fr}}
.gloss div{border-top:2px solid var(--teal);padding:14px 0 10px}
.gloss dt{font-family:Sora,sans-serif;font-weight:600;font-size:1.1rem}
.gloss dt small{display:block;font-family:Inter,sans-serif;font-size:.85rem;color:var(--teal-dark);font-weight:600;margin-top:2px}
.gloss dd{margin:6px 0 0}
.gloss dd .why{display:block;color:var(--muted);font-size:.95rem;margin-top:6px}

/* figures */
.shots{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;align-items:start}
@media (max-width:760px){.shots{grid-template-columns:1fr 1fr}}
@media (max-width:480px){.shots{grid-template-columns:1fr}}
figure{margin:0}
.shots img{display:block;width:100%;border:1px solid var(--line);border-radius:14px}
figcaption{font-size:.9rem;color:var(--muted);margin-top:8px}

blockquote{margin:0 0 18px;border:1px solid var(--line);border-left:4px solid var(--teal);border-radius:var(--r);padding:18px 20px}
blockquote p{font-size:1.1rem;margin-bottom:.5em}
blockquote footer{font-size:.88rem;color:var(--muted)}
.why-box{margin-top:8px;font-size:.98rem}

/* stats + chart */
.big{font-family:Sora,sans-serif;font-weight:700;font-size:2.4rem;color:var(--teal-dark);line-height:1.05;display:block;margin-bottom:6px}
.chart{border:1px solid var(--line);border-radius:var(--r);padding:18px}
.chart svg{display:block;width:100%;height:auto}
.bars{display:grid;gap:8px;margin:6px 0 10px}
.barrow{display:grid;grid-template-columns:70px 1fr 44px;align-items:center;gap:10px;font-size:.95rem}
.bartrack{background:var(--tint);border-radius:5px;height:18px;overflow:hidden}
.barfill{display:block;height:100%;background:var(--teal);border-radius:5px}
.barfill.lite{background:var(--light)}
.w43{width:43%}.w7{width:7%}
details.data{margin-top:10px}
details.data summary{cursor:pointer;font-weight:600;color:var(--teal-dark)}
table{border-collapse:collapse;width:100%;font-size:.95rem}
th,td{text-align:left;padding:9px 10px;border-bottom:1px solid var(--line);vertical-align:top}
th{font-family:Sora,sans-serif;font-weight:600;border-bottom:2px solid var(--ink)}
.table-scroll{overflow-x:auto}

/* stack */
.stack{list-style:none;padding:0;margin:0;display:grid;gap:10px;counter-reset:s}
.stack li{display:flex;gap:14px;align-items:flex-start;border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;counter-increment:s}
.stack li:before{content:counter(s);flex:none;width:30px;height:30px;border-radius:50%;background:var(--teal);color:#fff;font:700 .95rem/30px Sora,sans-serif;text-align:center}
.stack b{font-family:Sora,sans-serif;font-weight:600;display:block}
.chips{list-style:none;padding:0;margin:10px 0 0;display:flex;flex-wrap:wrap;gap:8px}
.chips li{background:var(--tint);color:var(--teal-dark);font-weight:600;font-size:.88rem;border-radius:999px;padding:5px 12px}
.verdict{border:2px solid var(--teal);border-radius:var(--r);padding:20px 24px;margin-top:22px}

/* check list */
.check{list-style:none;padding:0;margin:0}
.check li{display:flex;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}
.check li:before{content:"";flex:none;width:18px;height:18px;border:2px solid var(--teal);border-radius:5px;margin-top:4px}

/* forms */
.formcard{background:var(--tint);border-radius:18px;padding:28px}
.field{margin-bottom:14px}
.field label{display:block;font-weight:600;margin-bottom:6px}
.field .opt{font-weight:400;color:var(--muted)}
.field input{width:100%;min-height:46px;padding:10px 12px;border:1.5px solid #7D9098;border-radius:10px;font:inherit;background:#fff;color:var(--ink)}
.field input:focus-visible{outline:3px solid var(--focus);outline-offset:1px;border-color:var(--focus)}
.field input[aria-invalid="true"]{border-color:var(--err)}
.err{display:block;color:var(--err);font-size:.9rem;margin-top:4px}
.consent{display:flex;gap:10px;align-items:flex-start;margin:10px 0;font-size:.95rem}
.consent input{width:20px;height:20px;margin:3px 0 0;flex:none;accent-color:var(--teal)}
.notice{font-size:.88rem;color:var(--muted);margin-top:10px}
.status{min-height:1.4em;font-weight:600;margin-top:10px}
.hp{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
.success{display:none}
.success.show{display:block}

/* author */
.author{display:flex;gap:18px;align-items:flex-start}
.author img{width:84px;height:84px;border-radius:50%;flex:none}

/* sources */
.sources{padding-left:1.3em}
.sources li{margin-bottom:.6em}
.sources small{display:block;color:var(--muted)}

/* guide cards on hub */
.gcard{display:flex;flex-direction:column;gap:6px;text-decoration:none;color:var(--ink);border:1px solid var(--line);border-radius:var(--r);padding:22px;height:100%}
.gcard:hover{border-color:var(--teal);box-shadow:0 2px 0 var(--teal)}
.gcard .tag{font-size:.8rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--teal-dark)}
.gcard.soon{background:var(--soft);border-style:dashed}

/* footer */
.site-footer{background:var(--ink);color:#E6EEF1;padding:48px 0 28px;margin-top:0}
.site-footer a{color:#fff}
.site-footer h2{font-size:.95rem;color:#fff;letter-spacing:.04em;margin-bottom:.8em}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-bottom:.45em}
.fgrid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:28px}
@media (max-width:860px){.fgrid{grid-template-columns:1fr 1fr}}
.fbase{border-top:1px solid #2E4750;margin-top:32px;padding-top:18px;display:flex;flex-wrap:wrap;gap:10px 22px;font-size:.9rem;color:#C9D6DB}
.linkbtn{text-align:left;background:none;border:0;padding:0;font:inherit;color:#fff;text-decoration:underline;text-underline-offset:3px;cursor:pointer}

/* cookie banner */
.cookie{position:fixed;left:16px;right:16px;bottom:16px;z-index:60;max-width:760px;margin:0 auto;background:#fff;border:1px solid var(--line);border-radius:16px;box-shadow:0 10px 30px rgba(17,37,43,.18);padding:18px 20px}
.cookie[hidden]{display:none}
.cookie h2{font-size:1.05rem;margin-bottom:.4em}
.cookie p{font-size:.95rem;margin-bottom:.8em}
.cookie .row{display:flex;flex-wrap:wrap;gap:10px}
.cookie .btn{min-height:44px;font-size:.95rem}
dialog.prefs{border:0;border-radius:18px;padding:0;max-width:560px;width:calc(100% - 32px);color:var(--ink)}
dialog.prefs::backdrop{background:rgba(17,37,43,.55)}
.prefs .in{padding:24px}
.prefs .opt{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;border-top:1px solid var(--line);padding:14px 0}
.prefs .opt p{margin:4px 0 0;font-size:.92rem;color:var(--muted)}
.prefs .opt label{font-weight:600}
.switch{appearance:none;-webkit-appearance:none;flex:none;width:48px;height:28px;border-radius:999px;background:#7D9098;position:relative;cursor:pointer;margin:0}
.switch:before{content:"";position:absolute;top:3px;left:3px;width:22px;height:22px;border-radius:50%;background:#fff;transition:left .15s}
.switch:checked{background:var(--teal)}
.switch:checked:before{left:23px}
.switch:disabled{opacity:.7;cursor:not-allowed}
.always{font-size:.85rem;font-weight:700;color:var(--ok);white-space:nowrap}

/* legal pages */
.legal h2{font-size:1.3rem;margin-top:1.6em}
.legal ul{padding-left:1.2em}
.legal li{margin-bottom:.4em}

@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
@media print{.site-header,.cookie,.site-footer,.nav{display:none}}
.plain{list-style:none;padding:0;margin:0}
.h3like{font-size:1.2rem}
.prefs .row{display:flex;flex-wrap:wrap;gap:10px;margin-top:12px}
.meta-line{font-size:.92rem;color:var(--muted);margin-top:14px}
.stat-note{font-size:.9rem;color:var(--muted)}
.mt{margin-top:22px}
.center{text-align:center}
.wrap.read{max-width:var(--max)}
.wrap.read>*{max-width:var(--read)}
@media (max-width:520px){
  .nav a:not(.btn){display:none}
  .nav .btn{font-size:.9rem;padding:8px 14px;white-space:nowrap}
  .site-header .wrap{min-height:60px}
  .cookie{left:8px;right:8px;bottom:8px;padding:14px 16px;max-height:70vh;overflow:auto}
  .cookie h2{font-size:1rem}
  .cookie p{font-size:.88rem;line-height:1.5}
  .cookie .row{gap:8px}
  .cookie .btn{flex:1 1 auto;padding:8px 12px;font-size:.9rem}
}
.optins{border:0;padding:0;margin:14px 0 6px}
.optins legend{font-weight:600;padding:0;margin-bottom:4px}
.optins .opt{font-weight:400;color:var(--muted)}