:root{
  --lavender:#EAF1F2; --lavender-2:#F6FAFB;
  --ink:#0E1622; --ink-read:#23313C; --ink-2:#38465A; --muted:#71808F;
  --line:#D4E0E5; --blue:#1257E6; --blue-deep:#0E3FAE; --green:#0FB39C;
  --blue-soft:#DCE9FD; --white:#FFFFFF;
  --shadow-sm:0 1px 3px rgba(14,22,34,.07);
  --shadow-md:0 12px 40px rgba(14,22,34,.10);
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;color:var(--ink);
  font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
  background:
    radial-gradient(1100px 600px at 50% -8%, #FFFFFF 0%, rgba(255,255,255,0) 58%),
    linear-gradient(180deg, var(--lavender) 0%, var(--lavender-2) 100%);
  background-attachment:fixed;
}
h1,h2,h3,.display{font-family:"Space Grotesk","Inter",sans-serif;letter-spacing:-.015em;}
a{color:inherit;text-decoration:none;}

/* ---- reading progress ---- */
#progress{position:fixed;top:0;left:0;height:3px;width:0;z-index:60;
  background:linear-gradient(90deg,var(--green),var(--blue));transition:width .08s linear;}

/* ---- nav ---- */
nav{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:22px;
  padding:15px 32px;backdrop-filter:saturate(160%) blur(10px);
  background:rgba(246,250,251,.78);border-bottom:1px solid var(--line);}
.brand{display:flex;align-items:center;gap:11px;}
.brand .mark{width:28px;height:28px;flex:none;}
.brand b{font-family:"Space Grotesk";font-weight:700;font-size:15px;letter-spacing:-.01em;}
.nav-spacer{flex:1;}
.nav-back{font-size:14px;font-weight:500;color:var(--ink-2);padding:8px 15px;border-radius:20px;
  border:1px solid var(--line);transition:all .15s;background:var(--white);}
.nav-back:hover{border-color:var(--blue);color:var(--blue);}
.nav-pn{display:flex;align-items:center;gap:8px;}
.nav-arrow{display:flex;align-items:center;gap:7px;height:34px;padding:0 13px;border-radius:20px;
  border:1px solid var(--line);background:var(--white);color:var(--ink-2);font-size:13.5px;
  font-weight:500;line-height:1;transition:all .15s;max-width:200px;}
.nav-arrow .ar{font-size:15px;flex:none;}
.nav-arrow .lbl{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.nav-arrow:hover{border-color:var(--blue);color:var(--blue);}
.nav-arrow.disabled{opacity:.32;pointer-events:none;}
@media(max-width:720px){.nav-arrow .lbl{display:none;}.nav-arrow{padding:0 11px;}}

/* ---- article ---- */
article{max-width:720px;margin:0 auto;padding:60px 28px 12px;}
.art-head{margin-bottom:36px;}
.eyebrow{font-size:12.5px;font-weight:600;letter-spacing:.2em;text-transform:uppercase;
  color:var(--blue);margin-bottom:16px;}
.art-head h1{font-size:clamp(30px,5vw,46px);font-weight:700;line-height:1.1;margin:0;color:var(--ink);}
.rule{width:64px;height:4px;border-radius:3px;margin-top:24px;
  background:linear-gradient(90deg,var(--blue),var(--green));}

.prose{font-family:"Newsreader",Georgia,"Times New Roman",serif;
  font-size:20px;line-height:1.74;color:var(--ink-read);}
.prose p{margin:0 0 24px;}
.prose em{font-style:italic;}
.prose .lead{font-size:21px;}
.prose .lead::first-letter{
  font-family:"Space Grotesk";font-weight:700;font-size:3.5em;line-height:.82;
  float:left;margin:6px 12px 0 0;color:var(--blue);}
.prose h3{font-family:"Space Grotesk";font-weight:600;font-size:23px;color:var(--ink);
  margin:46px 0 16px;letter-spacing:-.01em;}
.prose figure{margin:36px 0;text-align:center;scroll-margin-top:120px;}
.prose figure img{max-width:100%;height:auto;background:var(--white);border:1px solid var(--line);
  border-radius:14px;padding:18px;box-shadow:var(--shadow-sm);}
.prose figcaption{font-family:"Inter";font-size:13px;color:var(--muted);line-height:1.5;
  margin-top:12px;max-width:560px;margin-left:auto;margin-right:auto;}

/* inline concept diagrams — placed next to the prose they illustrate, sized to the
   reading column, clickable to enlarge (the SVGs carry their own card chrome, so no
   extra frame). */
.prose figure.cfig{margin:32px 0;text-align:center;scroll-margin-top:120px;}
.prose figure.cfig img{display:block;width:100%;max-width:100%;height:auto;
  background:transparent;border:none;border-radius:14px;padding:0;box-shadow:none;}
.prose figure.cfig figcaption{font-family:"Inter";font-weight:600;font-size:13px;
  color:var(--muted);letter-spacing:.02em;margin-top:11px;}

/* ---- pull-quote call-outs ---- */
.callout{position:relative;margin:40px 0;padding:26px 30px 26px 34px;border-radius:16px;
  background:linear-gradient(135deg,#EEFBFE 0%,#F1FAFC 55%,#EAF7F5 100%);
  border:1px solid var(--line);box-shadow:var(--shadow-sm);overflow:hidden;}
.callout::before{content:"";position:absolute;left:0;top:0;bottom:0;width:5px;
  background:linear-gradient(180deg,var(--blue),var(--green));}
.callout .cmark{position:absolute;top:0;right:22px;font-family:"Newsreader",Georgia,serif;
  font-style:italic;font-size:96px;line-height:1;color:var(--blue);opacity:.12;pointer-events:none;}
.callout p{margin:0;position:relative;z-index:1;font-family:"Space Grotesk","Inter",sans-serif;
  font-weight:600;font-size:clamp(19px,2.5vw,23px);line-height:1.4;letter-spacing:-.012em;color:var(--ink);}
@media(max-width:560px){.callout{padding:22px 22px 22px 26px;}.callout .cmark{font-size:64px;right:14px;}}

/* ---- foot nav (prev/next) ---- */
.art-foot{max-width:720px;margin:48px auto 0;padding:0 28px;}
.pn-row{display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.pn{display:flex;flex-direction:column;gap:7px;padding:20px 22px;border:1px solid var(--line);
  border-radius:16px;background:var(--white);box-shadow:var(--shadow-sm);transition:transform .12s,border-color .15s;}
.pn:hover{transform:translateY(-2px);border-color:var(--blue);}
.pn.next{text-align:right;}
.pn-k{font-family:"Inter";font-size:12.5px;font-weight:600;color:var(--blue);
  letter-spacing:.03em;text-transform:uppercase;}
.pn-t{font-family:"Space Grotesk";font-weight:600;font-size:15.5px;color:var(--ink);line-height:1.3;}
.home-link{display:block;text-align:center;margin:30px auto 0;font-family:"Inter";font-weight:600;
  font-size:14.5px;color:var(--ink-2);padding:12px;border-radius:24px;transition:color .15s;}
.home-link:hover{color:var(--blue);}
@media(max-width:560px){.pn-row{grid-template-columns:1fr;}.pn.next{text-align:left;}}

/* ---- footer ---- */
footer{max-width:720px;margin:54px auto 0;padding:34px 28px 60px;border-top:1px solid var(--line);
  display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap;}
footer .f-brand{display:flex;align-items:center;gap:10px;color:var(--ink-2);font-size:14px;font-weight:500;
  font-family:"Space Grotesk";}
footer .f-brand .mark{width:20px;height:20px;}
footer .f-meta{font-size:13px;color:var(--muted);}

/* ---- inline concept-figure rail (links into the concept gallery) ---- */
.prose .concept-rail{margin:30px 0 10px;padding:20px 22px;background:var(--lavender-2);
  border:1px solid var(--line);border-radius:16px;}
.prose .concept-rail .crl-head{display:flex;align-items:baseline;gap:12px;flex-wrap:wrap;margin-bottom:14px;}
.crl-kick{font-family:"Space Grotesk";font-weight:700;font-size:11.5px;letter-spacing:1.4px;
  text-transform:uppercase;color:var(--blue);}
.crl-sub{font-size:13.5px;color:var(--muted);}
.crl-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(168px,1fr));gap:14px;}
.crl-card{display:block;text-decoration:none;border:1px solid var(--line);border-radius:11px;
  overflow:hidden;background:var(--white);transition:transform .15s,box-shadow .15s,border-color .15s;}
.crl-card:hover{transform:translateY(-3px);box-shadow:0 10px 26px rgba(14,22,34,.12);border-color:#C5D9F6;}
.crl-card img{display:block;width:100%;height:auto;border-bottom:1px solid var(--line);background:#fff;}
.crl-card .crl-t{display:block;padding:9px 11px 11px;font-family:"Space Grotesk";font-weight:600;
  font-size:13px;line-height:1.25;color:var(--ink);}