/* Palette and stroke language follow the MARS Lab mark:
   mint -> cyan forward strokes, blue -> indigo return strokes, charcoal wordmark. */
:root {
  --paper: #ffffff;
  --wash: #f4f7f9;
  --ink: #2c2d30;
  --ink-2: #55585f;
  --ink-3: #8a8e97;
  --rule: #dfe3e8;
  --mint: #00f6c6;
  --cyan: #0ac2ff;
  --blue: #1b9bff;
  --indigo: #4a26ff;
  --stroke: linear-gradient(90deg, var(--mint), var(--cyan) 45%, var(--indigo));
  --display: 'Outfit', 'IBM Plex Sans', system-ui, sans-serif;
  --body: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--indigo); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
b { font-weight: 600; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 28px; }

/* ---------- nav ---------- */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .9);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s;
}
.topnav.scrolled { border-bottom-color: var(--rule); }
.topnav-inner {
  max-width: 1120px; margin: 0 auto; padding: 0 28px;
  height: 60px; display: flex; align-items: center; justify-content: space-between; gap: 20px;
}
.brand {
  display: inline-flex; align-items: center; gap: 9px; flex: none;
  font-family: var(--display); font-weight: 600; font-size: 20px; letter-spacing: .01em; color: var(--ink);
}
.brand svg { width: 33px; height: 24px; }
.brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 22px; overflow-x: auto; scrollbar-width: none; }
.nav-links::-webkit-scrollbar { display: none; }
.nav-links a {
  position: relative; padding: 6px 0; white-space: nowrap;
  color: var(--ink-3); font-size: 14.5px;
}
.nav-links a:hover, .nav-links a.active { color: var(--ink); text-decoration: none; }
.nav-links a.active::after {
  content: ''; position: absolute; left: 0; right: 0; bottom: 0;
  height: 3px; border-radius: 3px; background: var(--stroke);
}

/* ---------- hero ---------- */
.hero { padding: 56px 0 8px; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: 40px; align-items: center; }
.venue {
  margin: 0 0 22px; font-family: var(--mono); font-size: 13.5px; letter-spacing: .06em; color: var(--ink-2);
  display: flex; align-items: center; gap: 12px;
}
.venue::before { content: ''; width: 34px; height: 8px; border-radius: 8px; background: var(--stroke); }
.title {
  margin: 0;
  font-family: var(--display); font-weight: 500;
  font-size: clamp(36px, 4.6vw, 60px); line-height: 1.05; letter-spacing: -.022em;
}
.title span { display: block; color: var(--indigo); }
.subtitle { margin: 22px 0 0; max-width: 30em; font-size: clamp(17px, 1.7vw, 20px); line-height: 1.5; color: var(--ink-2); }

.hero-art { min-width: 0; }
.mark { width: 100%; height: auto; display: block; overflow: visible; }
.mark .up { stroke: url(#g-up); }
.mark .dn { stroke: url(#g-down); }
.mark-notes text { font-family: var(--mono); font-size: 19px; fill: var(--ink-3); }

.byline { margin-top: 44px; padding-top: 26px; border-top: 1px solid var(--ink); }
.authors { display: flex; flex-wrap: wrap; gap: 4px 28px; font-family: var(--display); font-size: 21px; }
.authors a { color: var(--ink); }
.authors a:hover { color: var(--indigo); text-decoration: none; }
.authors sup, .affils sup { font-family: var(--mono); font-size: 11px; color: var(--ink-3); margin-left: 2px; }
.note { margin: 8px 0 0; font-size: 13.5px; color: var(--ink-3); }

.affils { list-style: none; margin: 26px 0 0; padding: 0; display: flex; flex-wrap: wrap; align-items: center; gap: 18px 36px; }
.affils li { display: flex; align-items: center; gap: 10px; font-size: 15px; color: var(--ink-2); }
.affils sup { margin: 0 -4px 22px 0; }
.affils img { height: 46px; width: auto; }
.affils img.wordmark { height: 26px; }
.affils .lab { margin-left: auto; padding-left: 36px; border-left: 1px solid var(--rule); }
.affils .lab img { height: 30px; }

.links { margin: 30px 0 0; display: flex; flex-wrap: wrap; gap: 10px; }
.btn {
  display: inline-flex; align-items: baseline; gap: 8px;
  padding: 9px 22px; border-radius: 999px;
  background: var(--ink); color: #fff; border: 1.5px solid var(--ink);
  font-size: 15px; font-weight: 500;
  transition: background .15s, border-color .15s;
}
.btn:hover { text-decoration: none; background: var(--indigo); border-color: var(--indigo); }
.btn small { font-family: var(--mono); font-size: 11.5px; }
.btn-ghost, .btn-ghost:hover { background: transparent; color: var(--ink-3); border-color: var(--rule); }

.showcase { margin-top: 52px; display: grid; gap: 26px; }
.showcase-item { margin: 0; }
.showcase-item img { border-radius: 6px; }
.showcase-item figcaption { margin-top: 10px; font-size: 15px; color: var(--ink-2); }
.tag { font-family: var(--mono); font-size: 12.5px; letter-spacing: .04em; color: var(--ink); margin-right: 14px; }

/* ---------- sections ---------- */
.section { padding: 44px 0; }
.section > .wrap::before { content: ''; display: block; border-top: 1px solid var(--ink); margin-bottom: 22px; }
.eyebrow { margin: 0 0 30px; font-family: var(--mono); font-size: 13px; letter-spacing: .05em; color: var(--ink-2); }
.eyebrow span { color: var(--indigo); margin-right: 14px; }
.h2 {
  margin: 0 0 26px; max-width: 21em;
  font-family: var(--display); font-weight: 500;
  font-size: clamp(28px, 3.5vw, 42px); line-height: 1.12; letter-spacing: -.018em;
}
.h3 { margin: 0 0 10px; font-family: var(--display); font-weight: 500; font-size: 21px; }
.prose { max-width: 46em; margin: 0 0 16px; color: var(--ink-2); }
.prose b { color: var(--ink); }
.small { font-size: 14.5px; color: var(--ink-2); margin: 12px 0; max-width: 52em; }

.tldr p {
  margin: 0; max-width: 28em;
  font-family: var(--display); font-weight: 400;
  font-size: clamp(22px, 2.6vw, 31px); line-height: 1.32; letter-spacing: -.01em;
}
.tldr b { font-weight: 500; color: var(--indigo); }

.stats { margin: 52px 0 56px; display: grid; grid-template-columns: repeat(5, 1fr); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.stat { padding: 22px 18px 22px 0; }
.stat + .stat { padding-left: 18px; border-left: 1px solid var(--rule); }
.stat-num { font-family: var(--display); font-weight: 500; font-size: 38px; line-height: 1; letter-spacing: -.02em; white-space: nowrap; }
.stat-num span { font-size: 20px; margin-left: 2px; }
.stat-num em { font-style: normal; color: var(--ink-3); font-weight: 400; }
.stat-num em::after {
  content: ''; display: inline-block; vertical-align: middle;
  width: 18px; height: 6px; margin: 0 7px 5px; border-radius: 6px; background: var(--stroke);
}
.stat-label { margin-top: 12px; font-size: 13px; line-height: 1.4; color: var(--ink-2); }

.figure { margin: 0 0 56px; }
.figure img { border-radius: 6px; }
.figure figcaption { margin-top: 14px; max-width: 62em; font-size: 14.5px; line-height: 1.6; color: var(--ink-2); }

.abstract { display: grid; grid-template-columns: 180px minmax(0, 1fr); gap: 24px; }
.abstract .prose { max-width: none; margin: 0; }

/* ---------- method ---------- */
.compare { display: grid; grid-template-columns: 1fr 1fr; }
.compare-card { padding: 4px 36px 4px 0; }
.compare-card + .compare-card { padding: 4px 0 4px 36px; border-left: 1px solid var(--rule); }
.kicker { margin: 0 0 4px; font-family: var(--mono); font-size: 12.5px; letter-spacing: .05em; color: var(--ink-3); }
.compare-card.good .kicker { color: var(--indigo); }
.compare-card h3 { margin: 0; font-family: var(--display); font-weight: 500; font-size: 22px; }
.compare-card.bad h3, .compare-card.bad .eq { color: var(--ink-2); }
.compare-card ul { list-style: none; margin: 0; padding: 0; font-size: 15.5px; color: var(--ink-2); }
.compare-card li { position: relative; padding: 7px 0 7px 22px; border-top: 1px solid var(--rule); }
.compare-card li::before { content: ''; position: absolute; left: 0; top: 17px; width: 10px; height: 4px; border-radius: 4px; background: var(--rule); }
.compare-card.good li::before { background: var(--stroke); }
.eq { overflow-x: auto; overflow-y: hidden; font-size: 16px; }

.steps { margin-top: 48px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; }
.step { border-top: 1px solid var(--ink); padding-top: 14px; }
.step-num { font-family: var(--mono); font-size: 13px; color: var(--indigo); }
.step h4 { margin: 8px 0 8px; font-family: var(--display); font-weight: 500; font-size: 20px; }
.step p { margin: 0; font-size: 15px; color: var(--ink-2); }

.callout {
  margin-top: 44px; padding: 18px 24px; max-width: 52em;
  background: var(--wash); border-radius: 6px; border-left: 6px solid var(--cyan);
  font-size: 15.5px; color: var(--ink-2);
}
.callout b { color: var(--ink); }

/* ---------- tabs ---------- */
.tabs { margin-top: 30px; }
.tab-bar { display: flex; gap: 28px; border-bottom: 1px solid var(--rule); overflow-x: auto; }
.tab {
  position: relative; border: 0; background: none; cursor: pointer; white-space: nowrap;
  font: inherit; font-family: var(--display); font-size: 17px; color: var(--ink-3);
  padding: 0 0 12px;
}
.tab:hover { color: var(--ink); }
.tab.active { color: var(--ink); }
.tab.active::after { content: ''; position: absolute; left: 0; right: 0; bottom: -1px; height: 4px; border-radius: 4px; background: var(--stroke); }
.tab-panel { display: none; margin-top: 26px; }
.tab-panel.active { display: block; }

/* ---------- real world ---------- */
.rw-grid { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 48px; align-items: start; }
.rw-media img { border-radius: 6px; }
.rw-media img + img { margin-top: 16px; }
.rw-media .plot { border: 1px solid var(--rule); padding: 6px; }
.metric, .ood-card { padding: 16px 0 18px; border-top: 1px solid var(--rule); }
.metric:first-child, .ood-card:first-child { border-top-color: var(--ink); }
.metric-head { display: flex; justify-content: space-between; font-family: var(--display); font-size: 17px; margin-bottom: 10px; }
.metric-head .up, .metric-head .down { font-family: var(--mono); font-size: 12px; color: var(--ink-3); }
.metric-head .up::after { content: ' higher is better'; }
.metric-head .down::after { content: ' lower is better'; }

.bar-row { display: grid; grid-template-columns: 78px 1fr 52px; align-items: center; gap: 12px; font-size: 13.5px; margin: 8px 0; }
.bar-row .who { color: var(--ink-3); }
.bar-row .val { text-align: right; font-family: var(--mono); font-size: 13px; color: var(--ink-2); }
.bar { height: 12px; border-radius: 12px; background: var(--wash); }
.bar i { display: block; height: 100%; border-radius: 12px; background: #c5cad2; width: 0; transition: width .9s cubic-bezier(.2, .8, .2, 1); }
.bar-row.ours .who { color: var(--ink); font-weight: 500; }
.bar-row.ours .val { color: var(--indigo); font-weight: 500; }
.bar-row.ours .bar i { background: var(--stroke); }
.pre-anim .bar i { width: 0 !important; }

/* ---------- adaptive ---------- */
.nfe-legend { display: flex; align-items: center; gap: 12px; font-family: var(--mono); font-size: 12.5px; color: var(--ink-3); margin: 22px 0 0; }
.jet {
  width: 220px; height: 8px; border-radius: 8px;
  background: linear-gradient(90deg, #00008f, #0050ff, #00d5ff, #7dff7a, #ffe600, #ff4e00, #800000);
}
.gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.gallery-row { margin-top: 18px; display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.gallery-group { margin: 0; }
.gallery-group figcaption { margin-top: 10px; font-size: 14px; color: var(--ink-3); }
.gallery-group figcaption b { font-weight: 500; color: var(--ink); }
.gallery img { border-radius: 4px; aspect-ratio: 1 / 1; object-fit: cover; }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14.5px; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
th, td { padding: 10px 12px; text-align: right; white-space: nowrap; }
td { font-family: var(--mono); font-size: 13.5px; }
th:first-child, td:first-child { text-align: left; padding-left: 14px; font-family: var(--body); font-size: 14.5px; }
th[colspan] { text-align: center; }
thead th { font-weight: 500; color: var(--ink-2); border-bottom: 1px solid var(--ink); }
thead tr:first-child:not(:last-child) th { border-bottom: 0; padding-bottom: 2px; }
thead tr.sub th { font-weight: 400; font-size: 12.5px; color: var(--ink-3); padding-top: 2px; }
tbody tr + tr td { border-top: 1px solid var(--rule); }
td b { font-weight: 500; color: var(--ink); }
tbody td { color: var(--ink-2); }
tr.ours td { background: #f0fafc; color: var(--ink); }
tr.ours td:first-child { font-weight: 500; box-shadow: inset 4px 0 0 var(--cyan); }
tr.ours td b { color: var(--indigo); }

/* ---------- ood ---------- */
.ood-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: start; }
.ood-title { font-family: var(--display); font-size: 17px; margin-bottom: 10px; }
.ood-card .bar-row { grid-template-columns: 92px 1fr 52px; }

/* ---------- bibtex ---------- */
.bib { position: relative; }
.bib pre {
  margin: 0; padding: 26px 28px; border-radius: 6px;
  background: var(--ink); color: #e9ecef; overflow-x: auto;
  font-family: var(--mono); font-size: 13.5px; line-height: 1.75;
}
.copy {
  position: absolute; top: 14px; right: 14px;
  border: 1px solid rgba(255, 255, 255, .28); background: none; color: #fff;
  font-family: var(--mono); font-size: 12px; padding: 5px 14px; border-radius: 999px; cursor: pointer;
}
.copy:hover { background: rgba(255, 255, 255, .12); }

.footer { padding: 8px 0 56px; }
.footer .wrap { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.footer .wrap::before { display: none; }
.footer img { height: 26px; }
.footer p { margin: 0; font-family: var(--mono); font-size: 12.5px; color: var(--ink-3); }

/* ---------- lightbox ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 100; display: none; place-items: center;
  background: rgba(20, 21, 24, .9); padding: 24px; cursor: zoom-out;
}
.lightbox.open { display: grid; }
.lightbox img { max-height: 92vh; max-width: 96vw; border-radius: 4px; }

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 28px; }
  .stats { grid-template-columns: repeat(3, 1fr); }
  .stat:nth-child(4) { padding-left: 0; border-left: 0; }
  .stat:nth-child(n+4) { border-top: 1px solid var(--rule); }
  .compare, .steps, .rw-grid, .ood-grid, .gallery-row, .abstract { grid-template-columns: 1fr; }
  .compare-card, .compare-card + .compare-card { padding: 0; border-left: 0; }
  .compare-card + .compare-card { margin-top: 32px; }
  .affils .lab { margin-left: 0; padding-left: 0; border-left: 0; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .wrap, .topnav-inner { padding: 0 18px; }
  .hero { padding-top: 32px; }
  .nav-links { gap: 16px; }
  .authors { font-size: 18px; gap: 2px 20px; }
  .affils { gap: 14px 24px; }
  .affils img { height: 38px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat, .stat + .stat { padding: 18px 12px 18px 0; border-left: 0; border-top: 1px solid var(--rule); }
  .stat:nth-child(-n+2) { border-top: 0; }
  .stat-num { font-size: 32px; }
  .metric-head .up::after, .metric-head .down::after { content: ''; }
}