/* =========================================================================
   Linear or Bilinear — project page
   Bespoke stylesheet (no external dependencies)
   ========================================================================= */

:root{
  --bg:#ffffff;
  --bg-soft:#f5f7fb;
  --bg-ink:#0e1120;
  --ink:#141824;
  --body:#3c4356;
  --muted:#767d8f;
  --line:#e7e9f0;
  --line-soft:#eef0f6;

  --brand:#2f6df6;
  --brand-deep:#1b4fd0;
  --brand-tint:#eef3ff;
  --violet:#7c5cf6;

  --ours:#2f6df6;
  --oracle:#12a150;
  --linear:#e5484d;
  --amber:#d9910a;

  --radius:16px;
  --radius-sm:10px;
  --shadow-sm:0 1px 2px rgba(20,24,36,.05), 0 2px 8px rgba(20,24,36,.04);
  --shadow-md:0 6px 24px rgba(20,24,36,.08), 0 2px 8px rgba(20,24,36,.05);
  --maxw:1080px;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans KR",sans-serif;
  --serif:"Iowan Old Style","Palatino Linotype",Palatino,Georgia,"Times New Roman",serif;
  --mono:"SFMono-Regular",ui-monospace,"JetBrains Mono","Cascadia Code",Menlo,Consolas,monospace;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--sans);color:var(--body);background:var(--bg);
  font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%;display:block}
a{color:var(--brand-deep);text-decoration:none;transition:color .15s}
a:hover{color:var(--brand)}
h1,h2,h3,h4{color:var(--ink);line-height:1.2;letter-spacing:-.01em;margin:0}
::selection{background:rgba(47,109,246,.18)}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.section{padding:76px 0}
.section--soft{background:var(--bg-soft);border-top:1px solid var(--line-soft);border-bottom:1px solid var(--line-soft)}
#abstract{border-bottom:1px solid var(--line)}
.eyebrow{
  display:inline-block;font-size:12.5px;font-weight:700;letter-spacing:.14em;
  text-transform:uppercase;color:var(--brand);margin-bottom:14px;
}
.section h2{font-size:32px;font-weight:800;margin-bottom:10px}
.section .lead{font-size:18px;color:var(--muted);max-width:760px;margin:0 0 40px}

/* ---------- nav ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.82);backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--line-soft);
}
.nav__inner{max-width:1180px;margin:0 auto;padding:12px 24px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.nav__brand{font-weight:800;color:var(--ink);font-size:15.5px;letter-spacing:-.01em;white-space:nowrap}
.nav__brand span{color:var(--brand)}
.nav__links{display:flex;gap:26px}
.nav__links a{color:var(--muted);font-size:14.5px;font-weight:600}
.nav__links a:hover{color:var(--ink)}
.nav__gh{display:inline-flex;align-items:center;gap:8px;color:var(--ink);font-weight:600;font-size:15px;transition:color .15s}
.nav__gh:hover{color:var(--brand)}
.nav__gh svg{width:20px;height:20px}
@media(max-width:820px){.nav__links{display:none}}

/* ---------- hero ---------- */
.hero{
  position:relative;overflow:hidden;padding:72px 0 60px;text-align:center;
  background:
    radial-gradient(820px 460px at 12% -12%, rgba(47,109,246,.15), transparent 58%),
    radial-gradient(760px 480px at 92% -6%, rgba(124,92,246,.13), transparent 55%),
    var(--bg);
}
.hero::before{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:
    linear-gradient(rgba(20,24,36,.025) 1px,transparent 1px),
    linear-gradient(90deg,rgba(20,24,36,.025) 1px,transparent 1px);
  background-size:44px 44px;
  -webkit-mask-image:radial-gradient(680px 380px at 50% 8%,#000,transparent 80%);
          mask-image:radial-gradient(680px 380px at 50% 8%,#000,transparent 80%);
}
.hero>*{position:relative}
.hero__venue{
  display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;
  color:var(--brand-deep);background:var(--brand-tint);border:1px solid rgba(47,109,246,.22);
  padding:6px 14px;border-radius:999px;margin-bottom:24px;letter-spacing:.02em;
}
.hero h1{
  font-family:var(--serif);font-weight:700;letter-spacing:-.02em;
  font-size:clamp(25px,4vw,43px);line-height:1.12;color:var(--ink);
  max-width:1000px;margin:0 auto 8px;white-space:nowrap;
}
@media(max-width:720px){.hero h1{white-space:normal}}
.hero h1 .accent{
  background:linear-gradient(100deg,var(--brand),var(--violet));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero__sub{font-size:19px;color:var(--body);max-width:660px;margin:18px auto 0;font-weight:450}
.authors{margin:30px auto 6px;display:flex;flex-wrap:wrap;gap:6px 26px;justify-content:center}
.author{font-size:18px;font-weight:650;color:var(--ink)}
.author a{color:var(--ink);border-bottom:1.5px solid transparent}
.author a:hover{color:var(--brand);border-color:var(--brand)}
.author sup{color:var(--brand);font-weight:800}
.affil{color:var(--muted);font-size:15.5px;margin-top:8px}
.affil .corr{font-size:13.5px;margin-top:2px}

.btns{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:34px}
.btn{
  display:inline-flex;align-items:center;gap:9px;font-weight:650;font-size:15px;
  padding:11px 20px;border-radius:999px;border:1px solid transparent;cursor:pointer;
  transition:transform .12s ease, box-shadow .15s ease, background .15s;
}
.btn svg{width:17px;height:17px}
.btn:hover{transform:translateY(-2px)}
.btn--primary{background:var(--ink);color:#fff;box-shadow:var(--shadow-sm)}
.btn--primary:hover{background:#000;color:#fff;box-shadow:var(--shadow-md)}
.btn--ghost{background:#fff;color:var(--ink);border-color:var(--line)}
.btn--ghost:hover{border-color:var(--brand);color:var(--brand-deep)}
.btn--soon{background:#fff;color:var(--muted);border-color:var(--line);cursor:default}
.btn--soon:hover{transform:none}
.btn--soon em{font-style:normal;font-weight:600;font-size:12.5px;color:#a2a8b6}

/* ---------- headline stats ---------- */
.statgrid{
  display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:52px;
}
.stat{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:22px 20px;text-align:left;box-shadow:var(--shadow-sm);
}
.stat__num{font-size:30px;font-weight:800;color:var(--ink);letter-spacing:-.02em;line-height:1}
.stat__num small{font-size:16px;font-weight:700;color:var(--muted)}
.stat__lab{font-size:13.5px;color:var(--muted);margin-top:9px;font-weight:550}
@media(max-width:820px){.statgrid{grid-template-columns:repeat(2,1fr)}}

/* ---------- demo (gifs) ---------- */
.demo{display:grid;grid-template-columns:1fr;gap:34px}
.figcard{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow-md);
}
.figcard__media{background:#fff;padding:8px}
.figcard__media img{width:100%;border-radius:8px}
.figcard__body{padding:18px 22px 22px;border-top:1px solid var(--line-soft)}
.figcard__title{font-size:17px;font-weight:750;color:var(--ink);margin-bottom:6px;display:flex;align-items:center;gap:10px}
.figcard__title .pill{font-size:11.5px;font-weight:700;padding:3px 10px;border-radius:999px;background:var(--brand-tint);color:var(--brand-deep)}
.figcard__desc{font-size:15px;color:var(--muted);margin:0}

/* legend chips */
.legend{display:flex;flex-wrap:wrap;gap:16px;margin-top:14px}
.chip{display:inline-flex;align-items:center;gap:8px;font-size:13.5px;font-weight:600;color:var(--body)}
.chip::before{content:"";width:14px;height:4px;border-radius:2px;background:var(--c,#999)}
.chip.dot::before{width:12px;height:12px;border-radius:50%}
.chip.ours{--c:var(--ours)} .chip.oracle{--c:var(--oracle)}
.chip.linear{--c:var(--linear)} .chip.ref{--c:#9aa1b2}

/* ---------- prose / abstract ---------- */
.prose{max-width:760px}
.prose p{margin:0 0 18px;font-size:17.5px;line-height:1.72}
.prose strong{color:var(--ink);font-weight:700}

/* ---------- criterion cards ---------- */
.crit{display:grid;grid-template-columns:1fr 1fr;gap:22px;margin-top:8px}
.critcard{
  border:1px solid var(--line);border-radius:var(--radius);padding:26px;background:#fff;
  box-shadow:var(--shadow-sm);position:relative;overflow:hidden;
}
.critcard--lin{border-top:4px solid var(--amber)}
.critcard--bi{border-top:4px solid var(--brand)}
.critcard h3{font-size:19px;margin-bottom:6px}
.critcard .tag{font-size:12.5px;font-weight:800;letter-spacing:.08em;text-transform:uppercase}
.critcard--lin .tag{color:var(--amber)} .critcard--bi .tag{color:var(--brand)}
.critcard p{font-size:15.5px;color:var(--body);margin:12px 0 0}
.critcard img{margin:16px 0 6px;background:#fff;border-radius:8px}
.formula{
  font-family:var(--mono);font-size:14px;background:var(--bg-soft);border:1px solid var(--line);
  border-radius:var(--radius-sm);padding:14px 16px;color:var(--ink);margin:26px 0 0;overflow-x:auto;
}
.formula b{color:var(--brand-deep)}
@media(max-width:760px){.crit{grid-template-columns:1fr}}

/* ---------- tables ---------- */
.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm);background:#fff}
table.tbl{width:100%;border-collapse:collapse;font-size:15px;min-width:560px}
table.tbl thead th{
  background:var(--bg-soft);color:var(--muted);font-weight:700;font-size:12.5px;
  text-transform:uppercase;letter-spacing:.05em;text-align:left;padding:14px 18px;
  border-bottom:1px solid var(--line);white-space:nowrap;
}
table.tbl td{padding:14px 18px;border-bottom:1px solid var(--line-soft);color:var(--body)}
table.tbl tbody tr:last-child td{border-bottom:none}
table.tbl tbody tr:hover{background:#fafbff}
table.tbl td.sys{font-weight:700;color:var(--ink)}
.syssub{display:block;font-size:11.5px;font-weight:600;color:var(--muted);margin-top:2px;letter-spacing:.01em}
table.tbl td .mono{font-family:var(--mono);font-size:13.5px}
.val{font-family:var(--mono);font-size:13.5px}
.val.o,.val.l,.val.b{color:var(--ink);font-weight:700}
.tblnote{font-size:13.5px;color:var(--muted);margin-top:14px}
.badge{display:inline-block;font-size:12px;font-weight:700;padding:2px 9px;border-radius:999px}
.badge.need{background:#fdecec;color:#c13636}
.badge.ok{background:#e9f7ef;color:#0f8a43}

/* ---------- plots grid ---------- */
.plots{display:grid;grid-template-columns:1fr 1fr;gap:22px;margin-top:8px}
.plotcard{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px 16px;box-shadow:var(--shadow-sm)}
.plotcard h4{font-size:16px;margin-bottom:2px}
.plotcard p{font-size:14px;color:var(--muted);margin:2px 0 12px}
.plotcard img{width:100%}
@media(max-width:760px){.plots{grid-template-columns:1fr}}

/* ---------- params ---------- */
.paramnote{display:flex;flex-direction:column;align-items:flex-start;gap:8px;margin-top:22px}
.pn{background:none;border:none;border-radius:0;box-shadow:none;padding:0;font-size:14.5px;color:var(--body)}
.pn b{color:var(--ink)}

/* ---------- bibtex ---------- */
.bibbox{position:relative;background:var(--bg-ink);border-radius:var(--radius);padding:24px 22px;box-shadow:var(--shadow-md)}
.bibbox pre{margin:0;font-family:var(--mono);font-size:13.5px;line-height:1.7;color:#c8d0e0;overflow-x:auto;white-space:pre}
.bibbox .k{color:#7fa8ff}.bibbox .s{color:#9fe0b0}
.copybtn{
  position:absolute;top:14px;right:14px;display:inline-flex;align-items:center;gap:7px;
  background:rgba(255,255,255,.08);color:#dfe5f0;border:1px solid rgba(255,255,255,.16);
  font-size:12.5px;font-weight:600;padding:7px 13px;border-radius:8px;cursor:pointer;transition:.15s;
}
.copybtn:hover{background:rgba(255,255,255,.16)}
.copybtn svg{width:14px;height:14px}

/* ---------- footer ---------- */
.footer{background:var(--bg-ink);color:#aeb6c6;padding:52px 0 40px;text-align:center}
.footer a{color:#cdd5e6}
.footer__lab{font-size:16px;font-weight:700;color:#fff;margin-bottom:6px}
.footer__meta{font-size:14px;line-height:1.7}
.footer__cc{font-size:12.5px;margin-top:22px;color:#7a8296}

/* math variable — renders Greek + combining accents (ν̂) like the paper */
.mv{font-family:"STIX Two Math","Cambria Math","Latin Modern Math","DejaVu Serif",Georgia,serif;font-style:italic;font-weight:500;text-transform:none}

/* demo blocks (paper-matching triptychs) */
.demoblock{margin-top:40px;padding-top:36px;border-top:1px solid var(--line)}
.demoblock:first-of-type{border-top:none;padding-top:8px;margin-top:16px}
.demoblock__head{margin-bottom:20px}
.demoblock h3{font-size:21px;font-weight:750;display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:8px}
.demoblock__head p{font-size:16px;color:var(--body);margin:0;max-width:760px}
.tagpill{font-size:12px;font-weight:800;letter-spacing:.04em;text-transform:uppercase;padding:4px 11px;border-radius:999px}
.tagpill.need{background:#eef3ff;color:var(--brand-deep)}
.tagpill.ok{background:#e9f7ef;color:#0f8a43}
.triptych{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.tri{background:none;border:none;border-radius:0;box-shadow:none}
.tri img{width:100%;display:block;background:#fff;border-radius:6px}
.tri__lab{font-size:14.5px;font-weight:700;text-align:center;padding:11px 4px 0;border-top:none;display:flex;align-items:center;justify-content:center;gap:8px}
.tri__lab::before{content:"";width:11px;height:11px;border-radius:50%;background:var(--c,#999)}
.tri__lab.oracle{--c:#4d4d4d;color:#4d4d4d}
.tri__lab.linear{--c:#EFB118;color:#EFB118}
.tri__lab.ours{--c:#4C8BF5;color:#4C8BF5}
.soloimg{border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow-sm);background:#fff}
.soloimg img{width:100%;display:block}
.structnote{margin-top:38px;background:var(--brand-tint);border:1px solid rgba(47,109,246,.18);border-radius:var(--radius);padding:20px 24px;font-size:15.5px;color:var(--ink)}
.structnote b{color:var(--brand-deep)}
@media(max-width:560px){.triptych{gap:6px}.tri__lab{font-size:11px;padding:6px 3px;gap:5px}}

/* justified body paragraphs */
.prose p,.lead,.demoblock__head p,.critcard p,.structnote,.contriblist li,.tblnote,.figcard__desc{text-align:justify;text-justify:inter-word;-webkit-hyphens:auto;hyphens:auto}
.hero__sub{text-align:justify;text-align-last:center;max-width:640px;-webkit-hyphens:auto;hyphens:auto}

/* contributions */
.contrib{margin-top:40px;padding-top:32px;border-top:1px solid var(--line)}
.contrib__title{font-size:14px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--brand);margin-bottom:20px}
.contriblist{margin:0;padding:0;list-style:none;counter-reset:c;display:grid;gap:15px;max-width:820px}
.contriblist li{position:relative;padding-left:46px;font-size:16.5px;color:var(--body);line-height:1.6}
.contriblist li::before{counter-increment:c;content:counter(c);position:absolute;left:0;top:1px;width:29px;height:29px;border-radius:9px;background:var(--brand-tint);color:var(--brand-deep);font-weight:800;font-size:14px;display:flex;align-items:center;justify-content:center}
.contriblist li b{color:var(--ink)}

/* demo group labels */
.demogroup{margin:46px 0 2px}
.demogroup:first-of-type{margin-top:26px}
.grouplabel{display:inline-flex;align-items:center;gap:9px;font-size:14px;font-weight:800;letter-spacing:.01em;padding:8px 16px;border-radius:999px}
.grouplabel::before{content:"";width:9px;height:9px;border-radius:50%;background:var(--c,#999)}
.grouplabel.need{background:#eef3ff;color:var(--brand-deep);--c:var(--brand)}
.grouplabel.ok{background:#e9f7ef;color:#0f8a43;--c:var(--oracle)}
.demogroup + .demoblock{border-top:none;padding-top:12px}

/* command class on demo headings */
.cmd{font-size:12.5px;font-weight:700;letter-spacing:.01em;padding:4px 12px;border-radius:999px;background:var(--bg-soft);color:var(--muted);border:1px solid var(--line);text-transform:none;white-space:nowrap}

/* ---- centered blocks, justified text ---- */
.section .eyebrow{display:block;text-align:center}
.section h2{text-align:center}
.section .lead{margin-left:auto;margin-right:auto;text-align:justify}
.prose{margin-left:auto;margin-right:auto}
.prose p{text-align:justify}
.demoblock__head{text-align:center}
.demoblock__head h3{justify-content:center}
.demoblock__head p{margin-left:auto;margin-right:auto;text-align:justify}
.demogroup{text-align:center}
.contrib__title{text-align:center}
.contriblist{margin-left:auto;margin-right:auto}
.critcard{text-align:center}
.critcard .tag{display:block}
.critcard p{text-align:justify}
.structnote{text-align:justify}
.tblnote{text-align:center}
.paramnote{justify-content:flex-start}

/* method: equations + algorithm */
.eqrow{display:grid;grid-template-columns:1fr 1fr;gap:22px;margin-top:8px}
.eqcard{border:1px solid var(--line);border-radius:var(--radius);padding:24px 22px;background:#fff;box-shadow:var(--shadow-sm);text-align:center}
.eqcard--lin{border-top:4px solid var(--amber)}
.eqcard--bi{border-top:4px solid var(--brand)}
.eqlabel{font-size:12.5px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;margin-bottom:16px}
.eqcard--lin .eqlabel{color:var(--amber)}
.eqcard--bi .eqlabel{color:var(--brand)}
.eq{font-family:"STIX Two Math","Cambria Math","Latin Modern Math",Georgia,serif;font-style:italic;font-size:22px;color:var(--ink);margin:4px 0 16px;line-height:1.4}
.eq b{font-weight:700}
.eqcard p{font-size:14.5px;color:var(--muted);margin:0;text-align:center}
.methodnote{max-width:760px;margin:28px auto 0;font-size:16px;color:var(--body);text-align:justify;line-height:1.7}
.methodnote b{color:var(--ink)}
.algo{max-width:720px;margin:34px auto 0;border:1px solid var(--line);border-radius:var(--radius);background:#fff;padding:22px 26px;text-align:left;box-shadow:var(--shadow-sm)}
.algo__title{font-size:13px;font-weight:800;letter-spacing:.05em;text-transform:uppercase;color:var(--brand-deep);margin-bottom:16px;text-align:center}
.algo ol{margin:0;padding-left:22px;display:grid;gap:10px}
.algo li{font-size:15px;color:var(--body);line-height:1.6}
.algo i{font-family:"STIX Two Math",Georgia,serif}
@media(max-width:760px){.eqrow{grid-template-columns:1fr}}

/* reveal-on-scroll — content is always visible; .in only adds a gentle entrance */
.reveal{opacity:1}
.reveal.in{animation:rise .6s cubic-bezier(.2,.7,.3,1) both}
@keyframes rise{from{opacity:.35;transform:translateY(16px)}to{opacity:1;transform:none}}
@media(prefers-reduced-motion:reduce){.reveal.in{animation:none}.btn:hover{transform:none}}