/* ===== Theme tokens ===== */
:root{
  --bg:#ffffff;
  --bg-alt:#f6f8fb;
  --surface:#ffffff;
  --text:#1a2230;
  --text-soft:#52607a;
  --muted:#7a869e;
  --border:#e4e9f2;
  --pm:#2f7d8c;        /* Perlmutter teal */
  --pm-soft:#e6f3f5;
  --fr:#c2531f;        /* Frontier orange */
  --fr-soft:#fbede4;
  --accent:#35798b;
  --accent-2:#3b6ea5;
  --shadow:0 6px 24px rgba(28,42,71,.08);
  --shadow-lg:0 18px 48px rgba(28,42,71,.14);
  --radius:14px;
  --maxw:1080px;
  --serif:'Source Serif 4',Georgia,serif;
  --sans:'Inter',system-ui,sans-serif;
  --mono:'JetBrains Mono',ui-monospace,monospace;
}
html[data-theme="dark"]{
  --bg:#0e131c;
  --bg-alt:#131b27;
  --surface:#18212f;
  --text:#e8edf6;
  --text-soft:#aeb9cd;
  --muted:#7f8ca5;
  --border:#26303f;
  --pm:#5cc2d4;
  --pm-soft:#13313a;
  --fr:#f0824b;
  --fr-soft:#3a2417;
  --accent:#5cc2d4;
  --accent-2:#6ea6e0;
  --shadow:0 6px 24px rgba(0,0,0,.35);
  --shadow-lg:0 18px 48px rgba(0,0,0,.5);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:74px}
body{
  margin:0;background:var(--bg);color:var(--text);
  font-family:var(--sans);line-height:1.65;
  -webkit-font-smoothing:antialiased;
  transition:background .3s,color .3s;
}
a{color:var(--accent-2);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3{line-height:1.2;letter-spacing:-.02em}

/* ===== Progress bar ===== */
#progress-bar{
  position:fixed;top:0;left:0;height:3px;width:0;z-index:1000;
  background:linear-gradient(90deg,var(--pm),var(--fr));
}

/* ===== Navbar ===== */
#navbar{
  position:sticky;top:0;z-index:900;
  background:color-mix(in srgb,var(--bg) 86%,transparent);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;padding:.7rem 1.25rem;
  display:flex;align-items:center;gap:1rem;
}
.nav-brand{font-weight:800;color:var(--text);font-size:1.02rem;letter-spacing:-.02em}
.nav-brand:hover{text-decoration:none;color:var(--accent)}
.nav-links{display:flex;gap:1.1rem;margin-left:auto;flex-wrap:wrap}
.nav-links a{color:var(--text-soft);font-size:.86rem;font-weight:500}
.nav-links a:hover{color:var(--accent);text-decoration:none}
#theme-toggle{
  background:var(--surface);border:1px solid var(--border);color:var(--text);
  width:38px;height:38px;border-radius:10px;cursor:pointer;
  display:grid;place-items:center;flex-shrink:0;transition:.2s;
}
#theme-toggle:hover{border-color:var(--accent);color:var(--accent)}
.icon-moon{display:none}
html[data-theme="dark"] .icon-sun{display:none}
html[data-theme="dark"] .icon-moon{display:block}

/* ===== Hero ===== */
.hero{position:relative;overflow:hidden;padding:4.5rem 1.25rem 0;text-align:center}
.hero-bg{
  position:absolute;inset:0;z-index:0;
  background:
    radial-gradient(60% 60% at 20% 0%,var(--pm-soft) 0%,transparent 60%),
    radial-gradient(60% 60% at 85% 10%,var(--fr-soft) 0%,transparent 55%);
  opacity:.9;
}
.hero-content{position:relative;z-index:1;max-width:880px;margin:0 auto}
.venue-chip{
  display:inline-block;font-size:.78rem;font-weight:600;letter-spacing:.04em;
  text-transform:uppercase;color:var(--accent);
  background:var(--surface);border:1px solid var(--border);
  padding:.35rem .85rem;border-radius:999px;margin-bottom:1.4rem;box-shadow:var(--shadow)
}
.hero-title{
  font-family:var(--serif);font-weight:600;
  font-size:clamp(1.9rem,4.6vw,3.1rem);margin:.2rem 0 1rem;
}
.hero-sub{font-size:clamp(1.02rem,2vw,1.22rem);color:var(--text-soft);max-width:680px;margin:0 auto 1.8rem}
.authors{display:flex;gap:.4rem 1.3rem;justify-content:center;flex-wrap:wrap;font-weight:600;font-size:1.05rem}
.author{position:relative}
.affil{color:var(--muted);font-size:.92rem;margin-top:.5rem}
.hero-links{display:flex;gap:.7rem;justify-content:center;flex-wrap:wrap;margin-top:1.8rem}
.btn{
  display:inline-flex;align-items:center;gap:.5rem;
  padding:.62rem 1.15rem;border-radius:10px;font-weight:600;font-size:.92rem;
  background:var(--surface);color:var(--text);border:1px solid var(--border);
  transition:.2s;box-shadow:var(--shadow)
}
.btn:hover{text-decoration:none;transform:translateY(-2px);box-shadow:var(--shadow-lg);border-color:var(--accent)}
.btn-primary{background:linear-gradient(135deg,var(--pm),var(--accent-2));color:#fff;border:none}
.btn svg{flex-shrink:0}

/* ===== Stats strip ===== */
.stats-strip{
  position:relative;z-index:1;max-width:var(--maxw);margin:3.2rem auto 0;
  display:grid;grid-template-columns:repeat(4,1fr);gap:1px;
  background:var(--border);border:1px solid var(--border);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow)
}
.stat{background:var(--surface);padding:1.4rem 1rem;text-align:center}
.stat-num{font-size:clamp(1.6rem,3.5vw,2.3rem);font-weight:800;color:var(--accent);font-family:var(--sans);line-height:1}
.stat-label{font-size:.8rem;color:var(--muted);margin-top:.45rem}

/* ===== Sections ===== */
.section{max-width:var(--maxw);margin:0 auto;padding:4.2rem 1.25rem}
.section.alt{max-width:none;background:var(--bg-alt);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.section.alt>*{max-width:var(--maxw);margin-left:auto;margin-right:auto}
.section-head{margin-bottom:1.6rem}
.kicker{
  display:block;font-size:.78rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;
  color:var(--accent);margin-bottom:.4rem
}
.section-head h2{font-size:clamp(1.5rem,3.2vw,2.1rem);margin:0}
.sub{font-size:1.2rem;margin:2.4rem 0 .8rem;color:var(--text)}

/* ===== Prose ===== */
.prose{color:var(--text-soft);font-size:1.02rem;max-width:760px}
.prose.lead{font-size:1.14rem;color:var(--text);max-width:800px}
.prose.small{font-size:.9rem}
.prose p{margin:0 0 1rem}
.abstract-body{font-family:var(--serif);font-size:1.1rem;color:var(--text);max-width:820px}
.muted{color:var(--muted)}
.mono{font-family:var(--mono);font-size:.86em;background:var(--bg-alt);padding:.08em .4em;border-radius:5px;border:1px solid var(--border)}
.section.alt .mono{background:var(--bg)}

.keywords{display:flex;gap:.5rem;flex-wrap:wrap;margin-top:1.6rem}
.keywords span{
  font-size:.82rem;color:var(--accent);background:var(--pm-soft);
  padding:.3rem .8rem;border-radius:999px;border:1px solid color-mix(in srgb,var(--accent) 25%,transparent)
}

/* ===== Cards ===== */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:1.1rem;margin-bottom:2.6rem}
.card{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  padding:1.5rem;box-shadow:var(--shadow);transition:.25s
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.card-icon{font-size:1.7rem;margin-bottom:.6rem}
.card h3{font-size:1.08rem;margin:0 0 .5rem}
.card p{margin:0;font-size:.92rem;color:var(--text-soft)}

/* ===== Machine cards ===== */
.machine-grid{display:grid;grid-template-columns:1fr 1fr;gap:1.2rem;margin:1.6rem 0 1rem}
.machine-card{
  position:relative;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:1.6rem;box-shadow:var(--shadow);
  border-top:4px solid var(--accent)
}
.machine-card.pm{border-top-color:var(--pm)}
.machine-card.fr{border-top-color:var(--fr)}
.machine-tag{
  position:absolute;top:1.2rem;right:1.2rem;font-size:.72rem;font-weight:700;
  letter-spacing:.06em;color:var(--muted);text-transform:uppercase
}
.machine-card h3{font-size:1.4rem;margin:0 0 .8rem}
.machine-card.pm h3{color:var(--pm)}
.machine-card.fr h3{color:var(--fr)}
.machine-card ul{margin:0;padding-left:1.1rem;color:var(--text-soft);font-size:.93rem}
.machine-card li{margin-bottom:.35rem}

/* ===== Table ===== */
.table-wrap{overflow-x:auto;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);margin:.6rem 0 1rem}
table{border-collapse:collapse;width:100%;font-size:.9rem;background:var(--surface)}
thead th{
  background:var(--bg-alt);text-align:left;padding:.8rem 1rem;font-weight:700;
  color:var(--text);border-bottom:2px solid var(--border);white-space:nowrap
}
td{padding:.7rem 1rem;border-bottom:1px solid var(--border);color:var(--text-soft);vertical-align:top}
tbody tr:last-child td{border-bottom:none}
td b{color:var(--text)}
.num{text-align:right;font-variant-numeric:tabular-nums;font-weight:600;color:var(--text)}
td.mono{font-family:var(--mono);font-size:.8rem;background:none;border:none;padding:.7rem 1rem;color:var(--text-soft)}
.pill{display:inline-block;font-size:.74rem;font-weight:600;padding:.18rem .55rem;border-radius:6px;white-space:nowrap}
.pill.mpi{background:var(--pm-soft);color:var(--pm)}
.pill.ai{background:var(--fr-soft);color:var(--fr)}

/* ===== Figures ===== */
.figure{
  margin:1.6rem 0;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:1.2rem;box-shadow:var(--shadow);
  display:flex;flex-wrap:wrap;gap:.7rem;align-items:center;justify-content:center
}
.figure img{
  flex:1 1 280px;min-width:0;max-width:100%;height:auto;cursor:zoom-in;border-radius:6px;
  background:#fff;transition:transform .2s
}
.figure figcaption{
  flex-basis:100%;font-size:.86rem;color:var(--muted);margin-top:.6rem;line-height:1.5
}
.figure figcaption strong{color:var(--text)}
.figure-row{display:grid;grid-template-columns:1fr 1fr;gap:1.2rem}
.figure.wide{padding:1.4rem}

/* ===== Observe / takeaway boxes ===== */
.observe{
  position:relative;margin:2rem 0;padding:1.4rem 1.5rem 1.4rem 1.5rem;
  background:var(--pm-soft);border:1px solid color-mix(in srgb,var(--accent) 35%,transparent);
  border-left:5px solid var(--accent);border-radius:12px
}
.observe-badge{
  display:inline-block;font-size:.74rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase;
  color:#fff;background:var(--accent);padding:.25rem .7rem;border-radius:6px;margin-bottom:.6rem
}
.observe p{margin:0;color:var(--text);font-size:1rem}
.observe .mono{background:color-mix(in srgb,var(--accent) 12%,var(--surface))}

/* ===== Insights ===== */
.insight-grid{display:grid;grid-template-columns:1fr 1fr;gap:1.2rem;margin-bottom:2rem}
.insight-col{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  padding:1.6rem;box-shadow:var(--shadow)
}
.insight-col h3{display:flex;align-items:center;gap:.5rem;margin:0 0 .8rem;font-size:1.15rem}
.role-icon{font-size:1.3rem}
.insight-col ul{margin:0;padding-left:1.1rem;color:var(--text-soft)}
.insight-col li{margin-bottom:.6rem}
.conclusion-box{
  background:linear-gradient(135deg,var(--pm-soft),var(--fr-soft));
  border:1px solid var(--border);border-radius:var(--radius);padding:1.8rem 2rem;box-shadow:var(--shadow)
}
.conclusion-box h3{margin:0 0 .6rem;font-size:1.25rem}
.conclusion-box p{margin:0;color:var(--text);font-size:1.05rem}

/* ===== BibTeX ===== */
.bibtex-wrap{position:relative;background:#0d1320;border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden;border:1px solid var(--border)}
#bib-text{
  margin:0;padding:1.5rem;color:#cdd9ee;font-family:var(--mono);font-size:.84rem;
  overflow-x:auto;line-height:1.6
}
.copy-btn{
  position:absolute;top:.8rem;right:.8rem;background:#1e2a40;color:#cdd9ee;
  border:1px solid #33415a;border-radius:8px;padding:.35rem .8rem;cursor:pointer;font-size:.8rem;font-weight:600;transition:.2s
}
.copy-btn:hover{background:#2a3a57}
.copy-btn.copied{background:var(--accent);color:#fff;border-color:var(--accent)}
.ack{margin-top:1.4rem}

/* ===== Footer ===== */
footer{border-top:1px solid var(--border);background:var(--bg-alt);padding:2.4rem 1.25rem}
.footer-inner{max-width:var(--maxw);margin:0 auto;display:flex;justify-content:space-between;gap:1.5rem;flex-wrap:wrap;align-items:center}
.footer-inner strong{font-size:.98rem}
.footer-inner .muted{margin:.3rem 0 0;font-size:.88rem}
.footer-links{display:flex;gap:1.3rem}
.footer-links a{color:var(--text-soft);font-weight:600;font-size:.9rem}

/* ===== Lightbox ===== */
.lightbox{
  position:fixed;inset:0;z-index:2000;display:none;
  background:rgba(8,12,20,.92);backdrop-filter:blur(4px);
  align-items:center;justify-content:center;padding:2rem;cursor:zoom-out
}
.lightbox.open{display:flex}
#lightbox-img{max-width:95%;max-height:92%;border-radius:8px;background:#fff;box-shadow:0 20px 60px rgba(0,0,0,.6)}
.lightbox-close{
  position:absolute;top:1rem;right:1.4rem;background:none;border:none;color:#fff;
  font-size:2.6rem;line-height:1;cursor:pointer;opacity:.8
}
.lightbox-close:hover{opacity:1}

/* ===== Reveal animation (only when JS is active) ===== */
html.js .section, html.js .stats-strip{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease}
html.js .section.visible,html.js .stats-strip.visible{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){
  .section,.stats-strip{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}

/* ===== Responsive ===== */
@media(max-width:820px){
  .nav-links{display:none}
  .stats-strip{grid-template-columns:1fr 1fr}
  .machine-grid,.figure-row,.insight-grid{grid-template-columns:1fr}
  .footer-inner{flex-direction:column;align-items:flex-start}
}
@media(max-width:480px){
  .stats-strip{grid-template-columns:1fr 1fr}
  .hero{padding-top:3rem}
}