:root {
  --accent: #16697A;
  --accent-dark: #0F4C5C;
  --accent-light: #8CC3CB;
  --tint: #EEF6F7;
  --ink: #1d2a30;
  --text: #33424a;
  --muted: #66737B;
  --rule: #dfe6e8;
  --bg: #ffffff;
  --bg-soft: #f7f9fa;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

.wrap { max-width: 820px; margin: 0 auto; padding: 0 20px; }
.wrap.wide { max-width: 1120px; }

/* ---------- Hero ---------- */
.hero {
  padding: 72px 0 36px;
  text-align: center;
  background: linear-gradient(180deg, var(--tint) 0%, var(--bg) 100%);
}
.title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(28px, 4.6vw, 44px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 28px;
}
.authors {
  font-size: 17px;
  margin: 0 auto 6px;
  max-width: 760px;
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 2px 20px;
  color: var(--ink);
}
.authors a { color: var(--accent); }
.authors sup, .affils sup, .notes sup { color: var(--accent); font-size: 0.68em; margin-left: 1px; }
.affils {
  font-size: 15px; color: var(--text);
  margin: 10px 0 2px;
  display: flex; flex-wrap: wrap; justify-content: center; gap: 2px 20px;
}
.notes { font-size: 13px; color: var(--muted); margin: 4px 0 0; }

.links { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 26px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 20px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 15px; font-weight: 500;
  transition: background .15s ease, transform .15s ease;
}
.btn:hover { background: var(--accent-dark); text-decoration: none; transform: translateY(-1px); }
.btn svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.btn svg.fill { fill: currentColor; stroke: none; }
.btn.is-pending { background: #8a979d; cursor: default; }
.btn.is-pending:hover { transform: none; background: #8a979d; }

/* ---------- Sections ---------- */
main > section.wrap { margin-top: 80px; }
main > section.wrap.wide { margin-top: 36px; }
main > section.wrap:not([id]) { margin-top: 32px; }
main > section.wrap.teaser { margin-top: 8px; }
main > section.wrap.stats { margin-top: 44px; }

h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 30px;
  line-height: 1.25;
  color: var(--ink);
  text-align: center;
  margin: 0 0 22px;
}
h2::after {
  content: "";
  display: block;
  width: 44px; height: 3px;
  background: var(--accent);
  border-radius: 2px;
  margin: 14px auto 0;
}
h3 { font-family: var(--serif); color: var(--ink); font-weight: 600; }
h3.sub { font-size: 20px; margin: 34px 0 10px; }

p { margin: 0 0 14px; }
.abstract { text-align: justify; }

figure { margin: 0; }
figure + figure { margin-top: 36px; }
figcaption {
  font-size: 14px; line-height: 1.6;
  color: var(--muted);
  margin: 14px auto 0;
  max-width: 780px;
  text-align: justify;
}
figcaption b, .tcap b { color: var(--ink); font-weight: 600; }

/* ---------- Stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.stat { text-align: center; padding: 20px 8px; }
.stat + .stat { border-left: 1px solid var(--rule); }
.stat .num {
  display: block;
  font-family: var(--serif);
  font-size: 38px; font-weight: 600;
  color: var(--accent);
  line-height: 1.1;
}
.stat .lbl { display: block; font-size: 13px; color: var(--muted); margin-top: 6px; line-height: 1.45; }
.stat .lbl em { font-style: normal; color: var(--ink); font-weight: 500; }

/* ---------- Insights ---------- */
.insight {
  position: relative;
  margin-top: 26px;
  padding: 22px 26px 12px;
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
}
.insight-tag {
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent);
}
.insight h3 { font-size: 20px; line-height: 1.4; margin: 4px 0 10px; }
.takeaway {
  font-family: var(--serif);
  font-size: 19px; line-height: 1.6;
  color: var(--ink);
  text-align: center;
  padding: 6px 12px;
}
.takeaway em { color: var(--accent); }

/* ---------- Plots ---------- */
.plots { display: grid; gap: 12px; align-items: end; }
.plots.four { grid-template-columns: repeat(4, 1fr); }
.plots.three { grid-template-columns: repeat(3, 1fr); }
.plots img { width: 100%; }

.legend {
  list-style: none; padding: 0; margin: 12px 0 0;
  display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 26px;
  font-size: 14px; color: var(--ink);
}
.legend li { display: inline-flex; align-items: center; gap: 7px; }
.legend svg { width: 26px; height: 12px; }

/* ---------- Method ---------- */
.method-grid { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: 22px; margin-top: 30px; }
.method-item {
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 20px 22px 8px;
  font-size: 15px;
}
.method-item h3 { font-size: 19px; margin: 0 0 10px; display: flex; align-items: center; gap: 10px; }
.step {
  display: inline-grid; place-items: center;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--accent); color: #fff;
  font-family: var(--sans); font-size: 13px; font-weight: 600;
}
.eq { overflow-x: auto; overflow-y: hidden; margin: 4px 0 12px; padding: 2px 0; }
.eq .katex-display { margin: 6px 0; }

.split { display: grid; grid-template-columns: minmax(0,1.05fr) minmax(0,1fr); gap: 28px; align-items: center; margin-top: 12px; }
.split figcaption { margin-top: 10px; }

.algo {
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  font-size: 13.5px; line-height: 1.55;
  padding: 0 0 8px;
  overflow-x: auto;
}
.algo-head { padding: 7px 4px; border-bottom: 1px solid var(--ink); margin-bottom: 6px; }
.algo-in, .algo-kw { padding: 2px 4px; }
.algo ol { margin: 2px 0; padding-left: 34px; }
.algo li { padding: 1px 4px; }
.algo li::marker { color: #999; font-size: 12px; }
.algo li.hl { background: var(--tint); border-radius: 4px; }
.algo-foot { font-size: 12px; color: var(--muted); margin-top: 6px; padding: 0 4px; }
.note { font-size: 14px; color: var(--muted); text-align: center; margin-top: 22px; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin-top: 14px; }
.table-wrap.narrow { max-width: 720px; margin-left: auto; margin-right: auto; }
table.res {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  border-top: 1.5px solid var(--ink);
  border-bottom: 1.5px solid var(--ink);
}
table.res th, table.res td { padding: 6px 10px; text-align: center; }
table.res th { font-weight: 600; color: var(--ink); border-bottom: 1px solid var(--ink); }
table.res .l { text-align: left; }
table.res tr.grp td {
  text-align: left; font-style: italic; color: var(--muted);
  font-size: 13px; padding-top: 10px;
  border-bottom: 1px solid var(--rule);
}
table.res tbody tr:not(.grp):not(.ours):hover td { background: var(--bg-soft); }
table.res tr.ours td { background: var(--tint); font-weight: 600; color: var(--ink); }
table.res tr.grp + tr.ours td, table.res tr:not(.ours) + tr.ours td { border-top: 1px solid var(--accent-light); }
table.res tr.ours + tr.ours td { border-top: none; }
table.res tr.base td { border-bottom: 1px solid var(--rule); }
table.res b { font-weight: 700; color: var(--accent-dark); }
table.comp td.y { color: #2f8a5b; }
table.comp td.n { color: #c0533a; }
.tcap { font-size: 14px; color: var(--muted); margin-top: 10px; text-align: justify; }
.two-tables { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: 30px; }
.two-tables h3.sub { font-size: 17px; min-height: 2.9em; margin-bottom: 0; }

/* ---------- Gallery ---------- */
.tabs { display: flex; flex-wrap: wrap; gap: 6px; margin: 12px 0 16px; }
.tabs button {
  font: inherit; font-size: 13px;
  font-family: var(--mono);
  padding: 5px 12px;
  border: 1px solid var(--rule);
  background: #fff; color: var(--text);
  border-radius: 999px;
  cursor: pointer;
  transition: all .15s ease;
}
.tabs button:hover { border-color: var(--accent-light); color: var(--accent); }
.tabs button[aria-selected="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }

.gallery-in { max-width: 620px; margin: 0 auto; }
.gallery-in img { border-radius: 8px; width: 100%; transition: opacity .2s ease; }
.gallery-in figcaption { text-align: center; }

.t2i-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.t2i-item { margin: 0; }
.t2i-item img { width: 100%; aspect-ratio: 1; object-fit: cover; border-radius: 8px; background: var(--bg-soft); }
.t2i-item figcaption { font-size: 13px; font-style: italic; text-align: center; margin-top: 6px; color: var(--muted); }

/* ---------- BibTeX ---------- */
.bib { position: relative; }
.bib code { font-family: inherit; }
.bib pre {
  margin: 0;
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 18px 20px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13px; line-height: 1.6;
  color: var(--ink);
}
.copy {
  position: absolute; top: 10px; right: 10px;
  font: 500 12px var(--sans);
  padding: 4px 10px;
  border: 1px solid var(--rule); border-radius: 6px;
  background: #fff; color: var(--text);
  cursor: pointer;
}
.copy:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Footer ---------- */
.footer {
  margin-top: 72px;
  padding: 26px 0 34px;
  border-top: 1px solid var(--rule);
  text-align: center;
  font-size: 13px; color: var(--muted);
}
.footer p { margin: 0; }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .plots.four { grid-template-columns: repeat(2, 1fr); }
  .method-grid, .split, .two-tables { grid-template-columns: minmax(0,1fr); }
  .two-tables h3.sub { min-height: 0; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(3) { border-left: none; }
  .stat:nth-child(n+3) { border-top: 1px solid var(--rule); }
}
@media (max-width: 560px) {
  .wrap { padding: 0 16px; }
  .hero { padding-top: 48px; }
  .authors { font-size: 15.5px; gap: 0 14px; }
  .affils { font-size: 13.5px; gap: 0 12px; }
  h2 { font-size: 25px; }
  .plots.three { grid-template-columns: 1fr; max-width: 380px; margin: 0 auto; }
  .t2i-grid { grid-template-columns: repeat(2, 1fr); }
  .stat .num { font-size: 32px; }
  .insight { padding: 18px 18px 8px; }
  .takeaway { font-size: 17px; }
  .abstract, figcaption, .tcap { text-align: left; }
}

/* ---------- Compact layout ---------- */
main > section.wrap:not([id]) { margin-top: 32px; }
.stat .lbl { font-size: 13.5px; }
.insight-title {
  font-size: 18px; line-height: 1.45;
  display: flex; gap: 12px; align-items: flex-start;
  margin: 28px 0 16px;
}
.insight-title .step { flex: none; margin-top: 1px; }
#insights figure + .insight-title { margin-top: 44px; }
.lead-p { text-align: center; font-family: var(--serif); font-size: 18px; color: var(--ink); margin-bottom: 22px; }
.lead-p em { color: var(--accent); }
#method .eq { text-align: center; margin-top: 18px; font-size: 15px; }
#method .note { margin-top: 6px; }
#results .two-tables { margin-top: 12px; }
#results .two-tables h3.sub { min-height: 0; }
figcaption { text-align: left; }
.plots.four { gap: 8px; }

.takeaways {
  margin: 48px auto 0;
  padding: 22px 28px 10px;
  max-width: 720px;
  text-align: center;
  background: var(--tint);
  border-radius: 12px;
}
.takeaways-tag {
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent);
}
.takeaways p { font-family: var(--serif); font-size: 18px; line-height: 1.6; color: var(--ink); margin: 6px 0 12px; }
.takeaways em { color: var(--accent); }
.takeaways p + p { font-size: 17px; }

.method-list { list-style: none; padding: 0; margin: 22px 0 0; }
.method-list li { position: relative; padding-left: 18px; margin-bottom: 10px; }
.method-list li::before {
  content: ""; position: absolute; left: 0; top: .72em;
  width: 7px; height: 7px; border-radius: 50%; background: var(--accent);
}
.method-list b { color: var(--ink); }
.ssl {
  margin-top: 26px;
  padding: 16px 22px 4px;
  border-left: 3px solid var(--accent);
  background: var(--bg-soft);
  border-radius: 0 10px 10px 0;
}
.ssl p { margin: 6px 0 12px; }

/* ---------- Plain-Transformer emphasis & motivation ---------- */
.hl { color: var(--accent); font-weight: 600; }
figcaption.tagline {
  font-family: var(--serif);
  font-size: clamp(20px, 2.6vw, 27px);
  line-height: 1.35;
  color: var(--ink);
  text-align: center;
  margin-top: 22px;
  max-width: none;
}
.tagline-sub { text-align: center; font-size: 14px; color: var(--muted); margin: 6px 0 0; }
.why-grid { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: 18px; margin-top: 6px; }
.why {
  border: 1px solid var(--rule);
  border-top: 3px solid var(--accent);
  border-radius: 10px;
  padding: 16px 20px 4px;
  font-size: 15px;
}
.why-tag {
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent);
}
.why p { margin: 6px 0 12px; }
.why b { color: var(--ink); font-weight: 600; }
.motivation-fig { margin-top: 30px; }
.result-line {
  margin: 22px auto 0;
  max-width: 720px;
  text-align: center;
  font-family: var(--serif);
  font-size: 18px; line-height: 1.6;
  color: var(--ink);
}
#insights .lead-p { margin-top: -4px; }
@media (max-width: 860px) { .why-grid { grid-template-columns: minmax(0,1fr); } }

/* ---------- Motivation body text & core goal ---------- */
.fig-text { margin-top: 18px; font-size: 16.5px; color: var(--text); }
.fig-text p { margin: 0 0 8px; }
.fig-text b { color: var(--ink); }
.goal {
  margin: 40px auto 0;
  max-width: 740px;
  padding: 22px 30px 14px;
  text-align: center;
  background: var(--tint);
  border-radius: 12px;
}
.goal p { font-family: var(--serif); font-size: 20px; line-height: 1.55; color: var(--ink); margin: 8px 0 6px; }
.goal em { color: var(--accent); }
#results .lead-p { font-size: 17.5px; }

.why-para { font-size: 16.5px; line-height: 1.75; margin-top: 4px; }
.why-para b { color: var(--ink); font-weight: 600; }

.why-list { list-style: none; padding: 0; margin: 6px 0 0; font-size: 16.5px; }
.why-list li { position: relative; padding-left: 20px; margin-bottom: 10px; }
.why-list li::before {
  content: ""; position: absolute; left: 0; top: .72em;
  width: 8px; height: 8px; border-radius: 50%; background: var(--accent);
}
.why-list b { color: var(--ink); font-weight: 600; }
.why-summary {
  margin: 20px 0 0;
  padding: 12px 18px;
  border-left: 3px solid var(--accent);
  background: var(--tint);
  border-radius: 0 8px 8px 0;
  font-family: var(--serif); font-size: 18px; line-height: 1.55; color: var(--ink);
}
.why-summary em { color: var(--accent); }