/* ===== Design tokens ===== */
:root{
  --bg:#ffffff;
  --bg-alt:#f5f8f8;
  --bg-card:#ffffff;
  --bg-code:#f2f5f6;
  --fg:#12201e;
  --fg-muted:#556764;
  --fg-faint:#879794;
  --border:#e3e9e8;
  --border-strong:#c9d5d3;
  --accent:#0e7c6b;
  --accent-soft:#e4f3f0;
  --accent-2:#1f6feb;
  --accent-2-soft:#e8f0fe;
  --gold:#a9760b;
  --hf:#ffd21e;
  --red:#c0392b;
  --green:#2e7d32;
  --amber:#b7791f;
  --grid-line:rgba(14,124,107,.07);
  --shadow-sm:0 1px 2px rgba(16,32,30,.05);
  --shadow:0 1px 2px rgba(16,32,30,.04), 0 8px 24px -8px rgba(16,32,30,.10);
  --shadow-lg:0 2px 4px rgba(16,32,30,.05), 0 18px 40px -12px rgba(16,32,30,.18);
  --radius:16px;
  --radius-sm:11px;
  --maxw:1180px;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0c1211;
    --bg-alt:#111918;
    --bg-card:#141e1c;
    --bg-code:#0e1817;
    --fg:#e9f0ee;
    --fg-muted:#9fb0ad;
    --fg-faint:#788a87;
    --border:#22302d;
    --border-strong:#2f403c;
    --accent:#4fd1b5;
    --accent-soft:#10302a;
    --accent-2:#7cb2ff;
    --accent-2-soft:#132337;
    --gold:#e0b64a;
    --red:#f08b7e;
    --green:#6bcf74;
    --amber:#e0b64a;
    --grid-line:rgba(79,209,181,.06);
    --shadow-sm:0 1px 2px rgba(0,0,0,.35);
    --shadow:0 1px 2px rgba(0,0,0,.3), 0 10px 28px -10px rgba(0,0,0,.6);
    --shadow-lg:0 2px 6px rgba(0,0,0,.4), 0 22px 48px -14px rgba(0,0,0,.7);
  }
}
:root[data-theme="dark"]{
  --bg:#0c1211;
  --bg-alt:#111918;
  --bg-card:#141e1c;
  --bg-code:#0e1817;
  --fg:#e9f0ee;
  --fg-muted:#9fb0ad;
  --fg-faint:#788a87;
  --border:#22302d;
  --border-strong:#2f403c;
  --accent:#4fd1b5;
  --accent-soft:#10302a;
  --accent-2:#7cb2ff;
  --accent-2-soft:#132337;
  --gold:#e0b64a;
  --red:#f08b7e;
  --green:#6bcf74;
  --amber:#e0b64a;
  --grid-line:rgba(79,209,181,.06);
  --shadow-sm:0 1px 2px rgba(0,0,0,.35);
  --shadow:0 1px 2px rgba(0,0,0,.3), 0 10px 28px -10px rgba(0,0,0,.6);
  --shadow-lg:0 2px 6px rgba(0,0,0,.4), 0 22px 48px -14px rgba(0,0,0,.7);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth; scroll-padding-top:78px; -webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--bg);
  color:var(--fg);
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
  font-size:16px;
  line-height:1.65;
  font-feature-settings:"cv05","ss01";
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent-2); text-decoration:none}
a:hover{text-decoration:underline}
::selection{background:color-mix(in srgb,var(--accent) 26%,transparent)}
.container{max-width:var(--maxw); margin:0 auto; padding:0 20px}
.container.narrow{max-width:820px}
.mono{font-family:'JetBrains Mono',ui-monospace,Menlo,monospace; font-size:.92em}

/* ===== Nav ===== */
.nav{
  position:sticky; top:0; z-index:60;
  background:color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter:saturate(180%) blur(14px);
  -webkit-backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--border);
}
.nav-inner{max-width:var(--maxw); margin:0 auto; padding:9px 20px; display:flex; align-items:center; gap:18px}
.nav-brand{display:flex; align-items:center; gap:9px; font-weight:700; color:var(--fg); font-size:15px; white-space:nowrap; letter-spacing:-.01em}
.nav-brand:hover{text-decoration:none}
.brand-mark{
  display:inline-grid; place-items:center; width:27px; height:27px; border-radius:8px;
  background:linear-gradient(135deg,var(--accent),var(--accent-2)); color:#fff; font-size:10px; font-weight:800; letter-spacing:.4px;
  box-shadow:0 2px 8px -2px color-mix(in srgb,var(--accent) 60%,transparent);
}
.nav-links{display:flex; gap:4px; margin-left:auto; font-size:14px}
.nav-links a{
  color:var(--fg-muted); white-space:nowrap; font-weight:500; padding:5px 11px; border-radius:8px; transition:.16s;
}
.nav-links a:hover{color:var(--accent); background:var(--accent-soft); text-decoration:none}
.nav-links a.active{color:var(--accent); background:var(--accent-soft)}
.nav-icons{display:flex; gap:6px; margin-left:8px}
.icon-btn{
  display:grid; place-items:center; width:32px; height:32px; border-radius:9px; flex-shrink:0;
  background:none; border:1px solid var(--border); color:var(--fg-muted);
  font-size:13px; font-family:inherit; cursor:pointer; transition:.16s;
}
.icon-btn:hover{color:var(--accent); border-color:var(--accent); background:var(--accent-soft); text-decoration:none}

/* ===== Hero ===== */
.hero{position:relative; padding:60px 0 44px; text-align:center; overflow:hidden; border-bottom:1px solid var(--border)}
.hero-grid{
  position:absolute; inset:0; pointer-events:none;
  background-image:linear-gradient(var(--grid-line) 1px,transparent 1px),linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:44px 44px;
  mask-image:radial-gradient(70% 60% at 50% 25%,#000 30%,transparent 100%);
  -webkit-mask-image:radial-gradient(70% 60% at 50% 25%,#000 30%,transparent 100%);
}
.hero-glow{
  position:absolute; inset:-45% 0 auto 0; height:560px; pointer-events:none;
  background:radial-gradient(55% 55% at 50% 42%, color-mix(in srgb, var(--accent) 15%, transparent), transparent 72%);
}
.hero .container{position:relative}
.venue-badge{
  display:inline-flex; align-items:center; gap:8px; font-size:12.5px; font-weight:600;
  color:var(--accent); background:var(--accent-soft); border:1px solid color-mix(in srgb,var(--accent) 24%, transparent);
  padding:6px 15px; border-radius:999px; margin-bottom:22px; letter-spacing:.01em;
}
.title{margin:0 0 24px; line-height:1.14}
.title-name{
  display:block; font-size:clamp(40px,7.2vw,66px); font-weight:800; letter-spacing:-.03em;
  background:linear-gradient(105deg,var(--accent) 5%,var(--accent-2) 95%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
  padding-bottom:2px;
}
.title-sub{display:block; margin-top:6px; font-size:clamp(17px,2.6vw,25px); font-weight:600; color:var(--fg); letter-spacing:-.015em}
.authors{display:flex; flex-direction:column; gap:3px; font-size:16px; margin-bottom:15px}
.author-row{display:flex; flex-wrap:wrap; justify-content:center; gap:2px 15px}
.author{color:var(--fg); font-weight:500}
.author sup{color:var(--accent); font-size:.68em; margin-left:1px; font-weight:600}
.affiliations{display:flex; flex-wrap:wrap; justify-content:center; gap:4px 22px; color:var(--fg-muted); font-size:14.5px}
.affiliations sup{color:var(--accent); font-weight:600}
.author-notes{display:flex; flex-wrap:wrap; justify-content:center; gap:4px 16px; color:var(--fg-faint); font-size:12.5px; margin-top:8px}
.author-notes sup{color:var(--accent)}

.buttons{display:flex; flex-wrap:wrap; justify-content:center; gap:10px; margin:30px 0 6px}
.btn{
  display:inline-flex; align-items:center; gap:8px; padding:10px 19px; border-radius:999px;
  background:var(--bg-card); border:1px solid var(--border-strong); color:var(--fg);
  font-size:14.5px; font-weight:600; transition:.18s cubic-bezier(.2,.7,.3,1); box-shadow:var(--shadow-sm);
}
.btn:hover{text-decoration:none; transform:translateY(-2px); border-color:var(--accent); color:var(--accent); box-shadow:var(--shadow)}
.btn-primary{
  background:linear-gradient(105deg,var(--accent),var(--accent-2)); border-color:transparent; color:#fff;
  box-shadow:0 4px 16px -4px color-mix(in srgb,var(--accent) 55%,transparent);
}
.btn-primary:hover{color:#fff; filter:brightness(1.07); border-color:transparent}
.btn-hf{border-color:color-mix(in srgb,var(--hf) 65%,var(--border-strong))}
.btn-hf:hover{border-color:var(--hf); color:var(--fg)}
.btn-disabled{opacity:.5; cursor:not-allowed; box-shadow:none}
.btn-disabled:hover{transform:none; border-color:var(--border-strong); color:var(--fg)}
.btn em{
  font-style:normal; font-weight:600; font-size:10.5px; letter-spacing:.05em; text-transform:uppercase;
  color:var(--fg-faint); border:1px solid var(--border); border-radius:5px; padding:1px 5px;
}

.stat-strip{display:flex; flex-wrap:wrap; justify-content:center; gap:10px; margin-top:32px}
.stat{
  min-width:120px; padding:13px 17px; border-radius:var(--radius-sm); background:var(--bg-card);
  border:1px solid var(--border); box-shadow:var(--shadow-sm); transition:.18s;
}
.stat:hover{border-color:color-mix(in srgb,var(--accent) 40%,var(--border)); transform:translateY(-2px)}
.stat b{display:block; font-size:21px; font-weight:750; color:var(--accent); letter-spacing:-.02em; font-variant-numeric:tabular-nums}
.stat span{display:block; font-size:12.5px; color:var(--fg-muted)}

/* ===== Sections ===== */
.section{padding:70px 0}
.section-tight{padding:40px 0 14px}
.section-alt{background:var(--bg-alt); border-top:1px solid var(--border); border-bottom:1px solid var(--border)}
.eyebrow{
  text-align:center; font-size:11.5px; font-weight:700; letter-spacing:.14em; text-transform:uppercase;
  color:var(--accent); margin-bottom:8px;
}
.section-title{font-size:31px; font-weight:750; letter-spacing:-.025em; text-align:center; margin:0 0 10px}
.section-title::after{
  content:""; display:block; width:48px; height:3px; border-radius:2px; margin:13px auto 28px;
  background:linear-gradient(90deg,var(--accent),var(--accent-2));
}
.sub-title{
  font-size:19px; font-weight:700; margin:46px 0 14px; letter-spacing:-.015em;
  padding-left:13px; border-left:3px solid color-mix(in srgb,var(--accent) 60%,transparent);
}
.lead{color:var(--fg-muted); text-align:center; max-width:840px; margin:0 auto 28px; font-size:16.5px}
.lead.small{font-size:14.5px}
.abstract{font-size:17px; line-height:1.82; text-align:justify; hyphens:auto}
.abstract b{font-weight:650; color:var(--fg)}
.mark-b1{color:var(--accent)}

/* ===== Reveal ===== */
.reveal{opacity:0; transform:translateY(14px); transition:opacity .55s ease, transform .55s cubic-bezier(.2,.7,.3,1)}
.reveal.in{opacity:1; transform:none}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1; transform:none; transition:none}
}

/* ===== Figures ===== */
.figure{margin:0 0 8px; text-align:center}
.figure img{
  max-width:100%; height:auto; border-radius:var(--radius);
  border:1px solid var(--border); background:#fff; box-shadow:var(--shadow);
}
.figure figcaption, .caption{
  margin:16px auto 0; max-width:960px; font-size:14px; line-height:1.72; color:var(--fg-muted); text-align:left;
}
.figure figcaption b, .caption b{color:var(--fg)}
.figure.ring img{border:none; background:transparent; box-shadow:none}

/* ===== Cards ===== */
.cards{display:grid; gap:18px}
.cards.three{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.card{
  background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius);
  padding:24px; box-shadow:var(--shadow-sm); transition:.2s cubic-bezier(.2,.7,.3,1);
}
.card:hover{box-shadow:var(--shadow); transform:translateY(-3px); border-color:color-mix(in srgb,var(--accent) 30%,var(--border))}
.card h3{margin:0 0 8px; font-size:17px; font-weight:700; letter-spacing:-.015em}
.card p{margin:0; color:var(--fg-muted); font-size:14.5px}
.card-icon{
  width:40px; height:40px; border-radius:11px; display:grid; place-items:center; margin-bottom:15px;
  background:linear-gradient(135deg,var(--accent-soft),color-mix(in srgb,var(--accent-2-soft) 70%,transparent));
  color:var(--accent); font-size:16px; border:1px solid color-mix(in srgb,var(--accent) 16%,transparent);
}
.tracks .card{border-top:3px solid var(--border)}
.track-r{border-top-color:#e0574f !important}
.track-e{border-top-color:#3d7fd6 !important}
.track-h{border-top-color:#2fb3aa !important}
.track-tag{font-size:11.5px; font-weight:700; letter-spacing:.09em; text-transform:uppercase; color:var(--fg-faint); margin-bottom:7px}
.chips{display:flex; flex-wrap:wrap; gap:6px; margin-top:15px}
.chips span{
  font-size:12px; padding:3px 11px; border-radius:999px;
  background:var(--bg-alt); border:1px solid var(--border); color:var(--fg-muted);
}

/* ===== Pipeline steps ===== */
.pipeline-steps{display:grid; gap:18px; grid-template-columns:repeat(auto-fit,minmax(270px,1fr))}
.step{
  position:relative; background:var(--bg-card); border:1px solid var(--border);
  border-radius:var(--radius); padding:24px 21px 20px; box-shadow:var(--shadow-sm); transition:.2s;
}
.step:hover{box-shadow:var(--shadow); transform:translateY(-3px)}
.step-num{
  position:absolute; top:-14px; left:21px; width:30px; height:30px; border-radius:9px;
  display:grid; place-items:center; font-size:13px; font-weight:750; color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));
  box-shadow:0 3px 10px -3px color-mix(in srgb,var(--accent) 65%,transparent);
}
.step h4{margin:9px 0 8px; font-size:16px; font-weight:700}
.step p{margin:0; font-size:14.5px; color:var(--fg-muted)}

.metric-grid{display:grid; gap:18px; grid-template-columns:repeat(auto-fit,minmax(250px,1fr)); margin-top:28px}
.metric-group{background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius); padding:20px 22px}
.metric-group h4{margin:0 0 11px; font-size:15px; display:flex; align-items:center; gap:9px; color:var(--accent)}
.metric-group ul{margin:0; padding-left:18px; color:var(--fg-muted); font-size:14px}
.metric-group li{margin-bottom:6px}
.metric-group b{color:var(--fg); font-weight:600}

/* ===== Tables ===== */
.table-wrap{
  position:relative;
  background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius);
  overflow-x:auto; box-shadow:var(--shadow-sm);
  scrollbar-width:thin;
}
.table-wrap::-webkit-scrollbar{height:8px}
.table-wrap::-webkit-scrollbar-thumb{background:var(--border-strong); border-radius:4px}
.table{width:100%; border-collapse:collapse; font-size:14px}
.table th,.table td{padding:10px 13px; text-align:left; border-bottom:1px solid var(--border); white-space:nowrap}
.table thead th{
  background:var(--bg-alt); font-weight:650; font-size:12px; color:var(--fg-muted);
  letter-spacing:.02em; border-bottom:1px solid var(--border-strong); vertical-align:bottom;
}
.table td.num,.table th.num{text-align:right; font-variant-numeric:tabular-nums}
.table tbody tr:last-child td{border-bottom:none}
.table tbody tr{transition:background .12s}
.table tbody tr:hover{background:color-mix(in srgb,var(--accent) 6%, transparent)}
.table tr.group td{
  background:var(--bg-alt); font-weight:700; font-size:11.5px; letter-spacing:.09em;
  text-transform:uppercase; color:var(--fg-muted); text-align:center; padding:7px 13px;
}
.table tr.group.prop td{background:color-mix(in srgb,var(--accent) 13%, var(--bg-alt)); color:var(--accent)}
.table tr.group.open td{background:color-mix(in srgb,var(--accent-2) 13%, var(--bg-alt)); color:var(--accent-2)}
.table tr.ours td{background:var(--accent-soft)}
.table tr.total td{border-top:1px solid var(--border-strong); font-weight:600}
.table td.indent{padding-left:28px}
.table .model{font-weight:600}
.table .sticky-col{position:sticky; left:0; background:var(--bg-card); z-index:2}
.table .sticky-col::after{
  content:""; position:absolute; top:0; right:0; bottom:0; width:1px; background:var(--border);
}
.table tr.group .sticky-col{background:var(--bg-alt)}
.table thead .sticky-col{background:var(--bg-alt); z-index:3}
.table tbody tr:hover .sticky-col{background:color-mix(in srgb,var(--accent) 6%, var(--bg-card))}
.table th.grp{text-align:center; border-bottom:1px solid var(--border); font-size:11.5px; letter-spacing:.09em; text-transform:uppercase}
.table th.grp-v{color:var(--accent)}
.table th.grp-a{color:var(--accent-2)}
.table th.grp-av{color:var(--gold)}
.table th.grp-sub{text-align:center; font-weight:650}
.table .b1{
  font-weight:750; color:var(--accent);
  background:color-mix(in srgb,var(--accent) 12%, transparent);
  box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--accent) 22%, transparent);
}
.table .b2{text-decoration:underline; text-decoration-thickness:1.5px; text-underline-offset:3px; text-decoration-color:color-mix(in srgb,var(--accent) 55%,transparent)}
.table .yes{color:var(--green); font-weight:700}
.table .no{color:var(--red); font-weight:700}
.table .partial{color:var(--fg-faint); font-weight:700}
.table .good{color:var(--green); font-weight:700}
.table .warn{color:var(--amber); font-weight:700}
.table .bad{color:var(--red); font-weight:700}
.table-wrap.compact .table td,.table-wrap.compact .table th{padding:7.5px 13px}
.table .tag{
  font-size:10px; font-weight:700; padding:1px 7px; border-radius:999px; margin-left:7px;
  background:var(--bg-alt); border:1px solid var(--border); color:var(--fg-faint); letter-spacing:.04em;
  vertical-align:1px;
}
.table .tag.v{color:var(--accent); border-color:color-mix(in srgb,var(--accent) 32%,transparent); background:var(--accent-soft)}
.table .tag.a{color:var(--accent-2); border-color:color-mix(in srgb,var(--accent-2) 32%,transparent); background:var(--accent-2-soft)}
.table .tag.av{color:var(--gold); border-color:color-mix(in srgb,var(--gold) 32%,transparent)}
.table.wide-text td:nth-child(3){white-space:normal; min-width:260px}
.table.lb{font-size:13px}
.table.lb th,.table.lb td{padding:8.5px 9px}
.table.lb thead th{font-size:11px; line-height:1.35}
.table.lb .sticky-col{padding-left:15px; padding-right:14px}
.legend{margin-left:14px; white-space:nowrap}
.legend .yes{color:var(--green); font-weight:700}
.legend .no{color:var(--red); font-weight:700}
.legend .partial{color:var(--fg-faint); font-weight:700}

.stats-layout{display:grid; gap:26px; grid-template-columns:minmax(0,0.9fr) minmax(0,1.1fr); align-items:start}
.two-col{display:grid; gap:30px; grid-template-columns:repeat(auto-fit,minmax(340px,1fr)); align-items:start}
.two-col .sub-title{margin-top:0}
.two-col .table th,.two-col .table td{padding:8.5px 11px; white-space:normal}
.two-col .table th.num,.two-col .table td.num{white-space:nowrap}
.two-col .table td:first-child{min-width:150px}

/* ===== Tabs ===== */
.tabs{display:flex; gap:8px; justify-content:center; margin-bottom:22px; flex-wrap:wrap}
.tab{
  display:inline-flex; align-items:center; gap:8px; padding:9px 19px; border-radius:999px;
  border:1px solid var(--border-strong); background:var(--bg-card); color:var(--fg-muted);
  font-family:inherit; font-size:14px; font-weight:600; cursor:pointer; transition:.18s;
}
.tab:hover{color:var(--accent); border-color:var(--accent)}
.tab.active{
  background:linear-gradient(105deg,var(--accent),var(--accent-2)); border-color:transparent; color:#fff;
  box-shadow:0 4px 14px -4px color-mix(in srgb,var(--accent) 55%,transparent);
}
.tab-panel{display:none}
.tab-panel.active{display:block; animation:fade .28s ease}
@keyframes fade{from{opacity:0; transform:translateY(5px)} to{opacity:1; transform:none}}
.submit-note{
  margin-top:22px; padding:15px 19px; border-radius:var(--radius-sm); font-size:14px; color:var(--fg-muted);
  background:var(--accent-soft); border:1px solid color-mix(in srgb,var(--accent) 20%,transparent);
}
.submit-note i{color:var(--accent); margin-right:7px}

/* ===== Findings ===== */
.findings{display:grid; gap:16px; grid-template-columns:repeat(auto-fit,minmax(400px,1fr)); margin-bottom:38px}
.finding{
  display:flex; gap:17px; padding:22px; border-radius:var(--radius);
  background:var(--bg-card); border:1px solid var(--border); box-shadow:var(--shadow-sm); transition:.2s;
}
.finding:hover{box-shadow:var(--shadow); transform:translateY(-3px)}
.finding-num{
  flex-shrink:0; font-size:15px; font-weight:800; letter-spacing:-.01em; font-variant-numeric:tabular-nums;
  width:32px; height:32px; border-radius:9px; display:grid; place-items:center;
  color:var(--accent); background:var(--accent-soft); border:1px solid color-mix(in srgb,var(--accent) 18%,transparent);
}
.finding h3{margin:2px 0 7px; font-size:16.5px; font-weight:700; letter-spacing:-.015em}
.finding p{margin:0; font-size:14.5px; color:var(--fg-muted)}
.finding p b{color:var(--fg)}

/* ===== BibTeX ===== */
.bibtex-wrap{position:relative}
.bibtex-wrap pre{
  margin:0; padding:24px; border-radius:var(--radius); overflow-x:auto;
  background:var(--bg-code); border:1px solid var(--border);
  font-family:'JetBrains Mono',ui-monospace,Menlo,monospace; font-size:12.5px; line-height:1.75; color:var(--fg);
}
.copy-btn{
  position:absolute; top:13px; right:13px; padding:6px 13px; border-radius:8px; cursor:pointer;
  background:var(--bg-card); border:1px solid var(--border-strong); color:var(--fg-muted);
  font-family:inherit; font-size:12.5px; font-weight:600; transition:.18s;
}
.copy-btn:hover{color:var(--accent); border-color:var(--accent)}

/* ===== Footer ===== */
.footer{padding:42px 0; border-top:1px solid var(--border); text-align:center; color:var(--fg-faint); font-size:13.5px}
.footer-links{display:flex; justify-content:center; gap:10px; margin-bottom:18px; flex-wrap:wrap}
.footer-links a{
  color:var(--fg-muted); font-weight:500; font-size:14px; padding:6px 14px; border-radius:999px;
  border:1px solid var(--border);
}
.footer-links a:hover{color:var(--accent); border-color:var(--accent); background:var(--accent-soft); text-decoration:none}
.footer p{max-width:620px; margin:0 auto; line-height:1.65}

/* ===== Back to top ===== */
.to-top{
  position:fixed; right:20px; bottom:20px; width:42px; height:42px; border-radius:50%; z-index:55;
  display:grid; place-items:center; cursor:pointer;
  background:var(--bg-card); border:1px solid var(--border-strong); color:var(--fg-muted);
  box-shadow:var(--shadow); opacity:0; pointer-events:none; transform:translateY(8px); transition:.22s;
}
.to-top.show{opacity:1; pointer-events:auto; transform:none}
.to-top:hover{color:var(--accent); border-color:var(--accent)}

/* ===== Responsive ===== */
@media (max-width:1000px){
  .nav-links a{padding:5px 8px; font-size:13.5px}
}
@media (max-width:900px){
  .stats-layout{grid-template-columns:1fr}
  .nav-links{display:none}
}
@media (max-width:640px){
  .section{padding:50px 0}
  .section-title{font-size:26px}
  .abstract{font-size:15.5px; text-align:left}
  .findings{grid-template-columns:1fr}
  .stat{min-width:calc(50% - 5px); flex:1}
  .figure figcaption,.caption{font-size:13px}
  .table th,.table td{padding:8px 10px; font-size:13px}
  .sub-title{font-size:17.5px}
  .to-top{right:14px; bottom:14px}
}