/* =========================================================
   EliasSultan.pro — stylesheet
   Palette: white / black / light grey / dark navy
   Type:    Spectral (display) · IBM Plex Sans (body) · IBM Plex Mono (index)
   ========================================================= */

:root{
  --paper:#FFFFFF;
  --mist:#F4F6F9;
  --rule:#DCE2EB;
  --ink:#0B0F17;
  --slate:#55627A;
  --navy:#16305A;
  --navy-deep:#0F2444;

  --display:"Spectral",Georgia,"Times New Roman",serif;
  --body:"IBM Plex Sans",system-ui,-apple-system,Segoe UI,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;

  --shell:1180px;
  --prose:66ch;
  --gap:clamp(3.5rem,7vw,7rem);
}

*,*::before,*::after{box-sizing:border-box}

html{-webkit-text-size-adjust:100%}

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--body);
  font-size:clamp(1rem,.96rem + .18vw,1.0625rem);
  line-height:1.65;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;display:block}

a{color:var(--navy);text-decoration:none}
a:hover{text-decoration:underline;text-underline-offset:3px}

:focus-visible{outline:2px solid var(--navy);outline-offset:3px}

.shell{width:min(100% - 2.5rem,var(--shell));margin-inline:auto}

/* ---------- type ---------- */

h1,h2,h3,h4{font-family:var(--display);font-weight:600;color:var(--ink);letter-spacing:-.01em;margin:0}
h1{font-size:clamp(2.6rem,1.7rem + 3.6vw,4.5rem);line-height:1.03}
h2{font-size:clamp(1.9rem,1.5rem + 1.5vw,2.75rem);line-height:1.15}
h3{font-size:clamp(1.25rem,1.15rem + .5vw,1.5rem);line-height:1.25}
h4{font-family:var(--body);font-size:1rem;font-weight:600;letter-spacing:.01em}

p{margin:0 0 1.15em}
p:last-child{margin-bottom:0}

.lead{font-size:clamp(1.125rem,1.05rem + .45vw,1.375rem);line-height:1.55;color:var(--slate)}
.prose{max-width:var(--prose)}
.prose p + p{margin-top:0}

/* index labels — the running head of the site */
.index{
  font-family:var(--mono);
  font-size:.75rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--navy);
  margin:0 0 1.25rem;
  display:flex;
  align-items:center;
  gap:.75rem;
}
.index::after{content:"";flex:1;height:1px;background:var(--rule)}
.index--plain::after{display:none}

.meta{font-family:var(--mono);font-size:.75rem;letter-spacing:.1em;text-transform:uppercase;color:var(--slate)}

/* ---------- header ---------- */

.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--rule);
}
.site-header .shell{display:flex;align-items:center;justify-content:space-between;gap:1.5rem;min-height:72px}
.brand{font-family:var(--display);font-size:1.15rem;font-weight:600;color:var(--ink);letter-spacing:-.01em}
.brand:hover{text-decoration:none;color:var(--navy)}
.brand small{display:block;font-family:var(--mono);font-size:.625rem;letter-spacing:.18em;text-transform:uppercase;color:var(--slate);font-weight:400;margin-top:2px}

.site-nav{display:flex;align-items:center;gap:1.75rem}
.site-nav a{font-size:.9375rem;color:var(--slate)}
.site-nav a:hover,.site-nav a[aria-current="page"]{color:var(--ink);text-decoration:none}
.site-nav a[aria-current="page"]{box-shadow:inset 0 -1px 0 var(--navy)}
.site-nav .btn{color:var(--paper)}

.nav-toggle{display:none;border:1px solid var(--rule);background:var(--paper);border-radius:2px;padding:.5rem .75rem;font-family:var(--mono);font-size:.75rem;letter-spacing:.12em;text-transform:uppercase;cursor:pointer;color:var(--ink)}

@media (max-width:900px){
  .nav-toggle{display:block}
  .site-nav{
    position:absolute;top:100%;left:0;right:0;
    flex-direction:column;align-items:flex-start;gap:0;
    background:var(--paper);border-bottom:1px solid var(--rule);
    padding:.5rem 1.25rem 1.25rem;display:none;
  }
  .site-nav.open{display:flex}
  .site-nav a{padding:.7rem 0;width:100%;border-bottom:1px solid var(--rule)}
  .site-nav .btn{margin-top:1rem;border-bottom:0}
}

/* ---------- buttons ---------- */

.btn{
  display:inline-block;
  font-family:var(--body);font-size:.9375rem;font-weight:500;
  padding:.8rem 1.5rem;border-radius:2px;border:1px solid var(--navy);
  background:var(--navy);color:var(--paper);transition:background .18s ease,color .18s ease;
}
.btn:hover{background:var(--navy-deep);border-color:var(--navy-deep);text-decoration:none;color:var(--paper)}
.btn--ghost{background:transparent;color:var(--navy);border-color:var(--rule)}
.btn--ghost:hover{background:var(--mist);color:var(--navy);border-color:var(--navy)}

/* ---------- sections ---------- */

.section{padding-block:var(--gap)}
.section--mist{background:var(--mist);border-block:1px solid var(--rule)}
.section-head{max-width:var(--prose);margin-bottom:clamp(2.5rem,4vw,3.5rem)}
.section-head p{color:var(--slate);margin-top:1rem}

/* ---------- hero ---------- */

.hero{padding-block:clamp(3.5rem,7vw,6.5rem) clamp(3rem,5vw,5rem)}
.hero-grid{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,.9fr);gap:clamp(2.5rem,5vw,5rem);align-items:center}
.hero h1{margin-bottom:1rem}
.hero .role{font-family:var(--display);font-size:clamp(1.25rem,1.1rem + .7vw,1.65rem);color:var(--navy);line-height:1.3;margin-bottom:.35rem}
.hero .role span{display:block;font-family:var(--body);font-size:1rem;color:var(--slate);margin-top:.4rem;font-weight:400}
.hero .lead{margin:1.75rem 0 2.25rem;max-width:52ch}
.hero-actions{display:flex;flex-wrap:wrap;gap:.85rem}

.portrait{position:relative;border:1px solid var(--rule);background:var(--mist);aspect-ratio:4/5;overflow:hidden}
.portrait img{width:100%;height:100%;object-fit:cover}
.portrait-note{position:absolute;inset:auto 0 0 0;display:none;margin:0;padding:1rem;font-family:var(--mono);font-size:.7rem;line-height:1.5;letter-spacing:.06em;text-transform:uppercase;color:var(--slate);text-align:center}
.portrait--empty{display:grid;place-items:center}
.portrait--empty .portrait-note{display:block;position:static}

@media (max-width:860px){
  .hero-grid{grid-template-columns:1fr}
  .portrait{max-width:340px;aspect-ratio:1/1}
}

/* ---------- signature: the decision path ---------- */

.path{background:var(--navy);color:var(--paper);padding-block:clamp(2rem,3.5vw,2.75rem)}
.path-line{display:flex;align-items:center;flex-wrap:wrap;gap:0}
.path-node{
  font-family:var(--mono);font-size:.8125rem;letter-spacing:.14em;text-transform:uppercase;
  padding:.35rem .25rem;white-space:nowrap;
}
.path-node b{display:block;font-family:var(--body);font-size:.8125rem;font-weight:400;letter-spacing:0;text-transform:none;color:rgba(255,255,255,.62);margin-top:.35rem}
.path-arrow{flex:1;min-width:2rem;height:1px;background:rgba(255,255,255,.3);margin:0 1.25rem;position:relative}
.path-arrow::after{content:"";position:absolute;right:0;top:-3px;border:3.5px solid transparent;border-left-color:rgba(255,255,255,.55)}
@media (max-width:760px){
  .path-line{flex-direction:column;align-items:flex-start;gap:.25rem}
  .path-arrow{width:1px;height:1.5rem;flex:none;margin:.15rem 0 .15rem .5rem}
  .path-arrow::after{right:auto;left:-3px;top:auto;bottom:0;border-color:transparent;border-top-color:rgba(255,255,255,.55)}
}

/* ---------- generic grids ---------- */

.cols-2{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:clamp(2rem,4vw,3.5rem)}
.cols-3{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:clamp(1.75rem,3vw,2.75rem)}
.split{display:grid;grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);gap:clamp(2rem,5vw,4.5rem);align-items:start}
@media (max-width:860px){.split{grid-template-columns:1fr}}

.stack > * + *{margin-top:1.25rem}

/* ---------- research entries ---------- */

.entry{border-top:1px solid var(--rule);padding-top:2rem;margin-top:2.5rem}
.entry:first-of-type{margin-top:0}
.entry-head{display:flex;flex-wrap:wrap;align-items:baseline;gap:.75rem 1.25rem;margin-bottom:1.25rem}
.entry-ref{font-family:var(--mono);font-size:.8125rem;letter-spacing:.12em;color:var(--navy)}
.entry-date{font-family:var(--mono);font-size:.75rem;letter-spacing:.1em;text-transform:uppercase;color:var(--slate);margin-left:auto}
.entry h3{width:100%;max-width:34ch}
.entry-body{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:clamp(1.5rem,3vw,3rem)}
@media (max-width:820px){.entry-body{grid-template-columns:1fr}}
.field{margin-bottom:1.5rem}
.field:last-child{margin-bottom:0}
.field h4{color:var(--slate);text-transform:uppercase;font-family:var(--mono);font-size:.7rem;letter-spacing:.16em;font-weight:500;margin-bottom:.5rem}
.field p{margin:0}
.field ul{margin:0;padding-left:1.15rem}
.field li{margin-bottom:.5rem}
.field li:last-child{margin-bottom:0}

/* ---------- cards ---------- */

.card{border:1px solid var(--rule);background:var(--paper);padding:clamp(1.5rem,2.5vw,2rem)}
.card h3{margin-bottom:.75rem;font-size:1.25rem}
.card p{color:var(--slate);font-size:.9375rem}
.card .meta{display:block;margin-bottom:.9rem}
.card-link{display:inline-block;margin-top:1.1rem;font-size:.9375rem}

.status{display:inline-block;font-family:var(--mono);font-size:.6875rem;letter-spacing:.12em;text-transform:uppercase;padding:.25rem .55rem;border:1px solid var(--rule);color:var(--slate);background:var(--mist)}

/* ---------- timeline ---------- */

.timeline{border-top:1px solid var(--rule)}
.tl-row{display:grid;grid-template-columns:7rem minmax(0,1fr);gap:clamp(1rem,3vw,3rem);padding:1.4rem 0;border-bottom:1px solid var(--rule);align-items:baseline}
.tl-year{font-family:var(--mono);font-size:1rem;letter-spacing:.08em;color:var(--navy)}
.tl-row p{margin:0;color:var(--slate)}
.tl-row strong{color:var(--ink);font-weight:600;display:block;font-family:var(--display);font-size:1.125rem;margin-bottom:.2rem}
@media (max-width:600px){.tl-row{grid-template-columns:1fr;gap:.4rem}}

/* ---------- empty states ---------- */

.empty{border:1px dashed var(--rule);background:var(--mist);padding:clamp(2rem,4vw,3rem);text-align:center}
.empty p{color:var(--slate);max-width:52ch;margin-inline:auto}
.empty .index{justify-content:center}
.empty .index::after{display:none}

.slot{border:1px dashed var(--rule);background:var(--mist);min-height:180px;display:grid;place-items:center;padding:1.5rem;text-align:center}
.slot span{font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;text-transform:uppercase;color:var(--slate);line-height:1.7}

/* ---------- definition list (media kit facts) ---------- */

.facts{margin:0;border-top:1px solid var(--rule)}
.facts div{display:grid;grid-template-columns:12rem minmax(0,1fr);gap:1.5rem;padding:1rem 0;border-bottom:1px solid var(--rule)}
.facts dt{font-family:var(--mono);font-size:.75rem;letter-spacing:.1em;text-transform:uppercase;color:var(--slate)}
.facts dd{margin:0}
@media (max-width:600px){.facts div{grid-template-columns:1fr;gap:.25rem}}

/* ---------- CTA strip ---------- */

.cta{background:var(--navy);color:var(--paper);padding-block:clamp(3rem,5vw,4.5rem)}
.cta h2{color:var(--paper);max-width:20ch}
.cta p{color:rgba(255,255,255,.72);max-width:52ch;margin-top:1rem}
.cta .btn{background:var(--paper);color:var(--navy);border-color:var(--paper);margin-top:1.75rem}
.cta .btn:hover{background:var(--mist);color:var(--navy-deep);border-color:var(--mist)}
.cta .index{color:rgba(255,255,255,.72)}
.cta .index::after{background:rgba(255,255,255,.25)}

/* ---------- footer ---------- */

.site-footer{border-top:1px solid var(--rule);padding-block:clamp(3rem,5vw,4rem) 2rem;background:var(--paper)}
.footer-grid{display:grid;grid-template-columns:minmax(0,1.4fr) repeat(2,minmax(0,1fr));gap:2.5rem}
@media (max-width:760px){.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}}
.footer-brand p{color:var(--slate);font-size:.9375rem;max-width:34ch;margin-top:.9rem}
.site-footer h4{font-family:var(--mono);font-size:.7rem;letter-spacing:.16em;text-transform:uppercase;color:var(--slate);font-weight:500;margin-bottom:1rem}
.site-footer ul{list-style:none;margin:0;padding:0}
.site-footer li{margin-bottom:.6rem}
.site-footer li a{color:var(--ink);font-size:.9375rem}
.site-footer li a:hover{color:var(--navy)}
.footer-base{margin-top:3rem;padding-top:1.5rem;border-top:1px solid var(--rule);display:flex;flex-wrap:wrap;gap:.75rem 2rem;justify-content:space-between}
.footer-base p{margin:0;font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;color:var(--slate);text-transform:uppercase}

/* ---------- motion ---------- */

.reveal{opacity:0;transform:translateY(14px)}
.reveal.in{opacity:1;transform:none;transition:opacity .6s ease,transform .6s ease}

@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
  html{scroll-behavior:auto}
}

/* ---------- anchor offset under the sticky header ---------- */
html{scroll-behavior:smooth}
:target{scroll-margin-top:100px}
.entry{scroll-margin-top:100px}

/* ---------- figures ---------- */
.figure{margin:0}
.figure img{width:100%;height:auto;border:1px solid var(--rule)}
.figure figcaption{margin-top:.85rem;font-family:var(--mono);font-size:.7rem;line-height:1.7;letter-spacing:.08em;text-transform:uppercase;color:var(--slate)}
.figure--kit img{aspect-ratio:4/5;object-fit:cover}

/* ---------- featured paper ---------- */
.paper{display:grid;grid-template-columns:minmax(0,.62fr) minmax(0,1.38fr);gap:clamp(2rem,4vw,3.5rem);align-items:start}
.paper-cover img{width:100%;height:auto;border:1px solid var(--rule);box-shadow:0 1px 0 var(--rule)}
.paper-body .lead{color:var(--navy)}
@media (max-width:820px){.paper{grid-template-columns:1fr}.paper-cover{max-width:280px}}
.paper-toc{margin:0;padding-left:1.4rem;font-size:.9375rem;color:var(--slate)}
.paper-toc li{margin-bottom:.55rem}
.paper-toc li::marker{font-family:var(--mono);font-size:.75rem;color:var(--navy)}
.citation{background:var(--paper);border-left:2px solid var(--navy);padding:1rem 1.25rem;font-size:.9375rem;color:var(--slate)}
.citation i{color:var(--ink)}

/* ---------- hero subline + diagrams ---------- */
.lead-sub{font-size:1rem;color:var(--slate);max-width:52ch;margin:-1.25rem 0 2.25rem}
.diagram{margin:0}
.diagram svg{width:100%;height:auto;display:block}
.diagram figcaption{margin-top:1.25rem;font-family:var(--mono);font-size:.7rem;line-height:1.7;letter-spacing:.08em;text-transform:uppercase;color:var(--slate);max-width:70ch}
.diagram figcaption b{color:var(--navy);font-weight:500}
.card--paper{border-color:var(--navy);border-width:1px}
.card--paper .meta{color:var(--navy)}

/* ---------- series structure + cross references ---------- */
.series{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:1.5rem;border-top:1px solid var(--rule);padding-top:1.75rem}
.series > div{border-left:2px solid var(--navy);padding-left:1rem}
.series-code{display:block;font-family:var(--mono);font-size:.75rem;letter-spacing:.14em;color:var(--navy);margin-bottom:.5rem}
.series b{display:block;font-family:var(--display);font-size:1.0625rem;font-weight:600;margin-bottom:.35rem}
.series p{margin:0;font-size:.875rem;color:var(--slate);line-height:1.55}

.cross-refs{list-style:none;margin:0;padding:0;border-top:1px solid var(--rule)}
.cross-refs li{display:flex;flex-wrap:wrap;gap:.25rem 1rem;justify-content:space-between;padding:.7rem 0;border-bottom:1px solid var(--rule);font-size:.9375rem}
.cross-refs span{font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--slate)}

.entry-rel{border-top:1px solid var(--rule);padding-top:1rem;margin-top:1.5rem}
.entry-rel p{font-size:.9375rem}