/* ============================================================
   Sapiens2 — Project Page
   Professional · classy · subtle · academic
   ============================================================ */

:root {
  --bg-dark: #0a0a0a;
  --bg-light: #fafafa;
  --bg-card: #ffffff;
  --text: #111111;
  --text-soft: #3a3a3a;
  --muted: #6b6b6b;
  --hairline: rgba(0, 0, 0, 0.08);
  --hairline-dark: rgba(255, 255, 255, 0.16);
  --accent: #1a1a1a;

  --model-0: #bcd0dc;   /* dusty soft blue   — 0.4B */
  --model-1: #c2cfb6;   /* dusty sage green  — 0.8B */
  --model-2: #e0a89c;   /* dusty salmon red  — 1B   */
  --model-3: #d6b8cc;   /* dusty mauve       — 5B   */

  --task-pose:   #b8c4dc;   /* dusty periwinkle */
  --task-seg:    #c8b8d4;   /* dusty lavender   */
  --task-normal: #b8d4c4;   /* dusty mint       */
  --task-albedo: #e4d0a8;   /* dusty sand       */

  --font-sans: 'Outfit', system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
  --font-display: 'Raleway', 'Outfit', system-ui, sans-serif;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --radius: 10px;
  --max-w: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 300;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg-light);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;                 /* prevent rogue horizontal scroll on mobile */
}

img, video, svg, canvas { max-width: 100%; }

a { color: inherit; text-decoration: none; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative;
  height: 100vh;
  min-height: 640px;
  width: 100%;
  overflow: hidden;
  background: var(--bg-dark);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(180deg, rgba(0,0,0,0.55) 0%, rgba(0,0,0,0.35) 35%, rgba(0,0,0,0.75) 100%),
    radial-gradient(ellipse at center, rgba(0,0,0,0) 0%, rgba(0,0,0,0.35) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  padding: 0 1.5rem;
  animation: fade-in 900ms var(--ease) 100ms both;
}

.eyebrow {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.72rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  opacity: 0.78;
  margin: 0 0 1.5rem;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(3.5rem, 9vw, 7rem);
  line-height: 1.0;
  letter-spacing: -0.02em;
  margin: 0;
}

.hero-title-num {
  font-size: 1.12em;
  font-weight: 500;
  line-height: 1;
  vertical-align: baseline;
  letter-spacing: 0;
  margin-left: 0.08em;
}

.hero-tagline {
  font-family: var(--font-sans);
  font-weight: 300;
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  line-height: 1.5;
  margin: 1.1rem auto 1.5rem;
  max-width: 640px;
  opacity: 0.92;
}

.hero-authors {
  font-family: var(--font-sans);
  font-weight: 300;
  font-style: italic;
  font-size: 0.86rem;
  opacity: 0.7;
  letter-spacing: 0.02em;
  margin: 0 0 1.75rem;
}

.hero-authors .affiliation {
  font-style: normal;
  opacity: 0.85;
}

.hero-authors a {
  color: inherit;
  border-bottom: 1px solid rgba(255, 255, 255, 0);
  transition: border-color 200ms var(--ease), opacity 200ms var(--ease);
}

.hero-authors a:hover {
  border-bottom-color: rgba(255, 255, 255, 0.55);
  opacity: 1;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 0.85rem 1.6rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: transparent;
  color: rgba(255, 255, 255, 0.95);
  cursor: pointer;
  transition: background 240ms var(--ease), border-color 240ms var(--ease),
              color 240ms var(--ease), transform 240ms var(--ease);
}

.btn:hover {
  background: rgba(255, 255, 255, 0.96);
  color: #000;
  border-color: rgba(255, 255, 255, 0.96);
  transform: translateY(-1px);
}

.btn.primary {
  background: rgba(255, 255, 255, 0.96);
  color: #000;
  border-color: rgba(255, 255, 255, 0.96);
}

.btn.primary:hover {
  background: #fff;
  transform: translateY(-1px);
}

.scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  display: block;
  padding: 0.5rem 0.75rem;
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  text-align: center;
  color: #fff;
  opacity: 0.55;
  cursor: pointer;
  animation: gentle-bob 2.6s var(--ease) infinite;
  transition: opacity 200ms var(--ease);
}

.scroll-hint:hover { opacity: 1; }

.scroll-hint::after {
  content: '';
  display: block;
  width: 1px;
  height: 28px;
  margin: 0.6rem auto 0;
  background: linear-gradient(to bottom, rgba(255,255,255,0.65), transparent);
}

@keyframes gentle-bob {
  0%, 100% { transform: translate(-50%, 0); opacity: 0.55; }
  50%      { transform: translate(-50%, 6px); opacity: 0.85; }
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   Section layout
   ============================================================ */
main { background: var(--bg-light); }

.section {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2.5rem 2rem;
}

.section-header {
  max-width: 720px;
  text-align: center;
  margin: 0 auto 1.75rem;
}

.section-header .eyebrow {
  color: var(--muted);
  opacity: 1;
  margin-bottom: 1rem;
}

.section-header h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
  margin: 0 0 0.5rem;
  color: var(--text);
}

.section-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.72rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.4rem;
  font-variant-numeric: tabular-nums;
}

.section-header .intro {
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.65;
  max-width: 580px;
  margin: 0 auto;
}

/* Sub-section header (h3) used inside larger sections */
.subsec-h {
  margin: 0 auto 1.5rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.35rem;
  letter-spacing: -0.01em;
  color: var(--text);
  text-align: center;
  max-width: var(--max-w);
}

/* Retrieval grid */
.retrieval {
  max-width: 900px;
  margin: 0 auto 1rem;
}

.retrieval-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 1.5rem;
  row-gap: 0.85rem;
  align-items: center;
}

.retrieval-head {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.66rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--hairline);
}

.retrieval-head--q { text-align: center; }

.retrieval-q {
  width: 96px;
  height: 128px;
  object-fit: cover;
  border-radius: 8px;
  display: block;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.retrieval-r {
  display: grid;
  grid-template-columns: repeat(5, 96px);
  gap: 0.75rem;
}

.retrieval-r img {
  width: 96px;
  height: 128px;
  object-fit: cover;
  border-radius: 6px;
  display: block;
  opacity: 0.92;
  transition: transform 220ms var(--ease), opacity 220ms var(--ease),
              box-shadow 220ms var(--ease);
}

.retrieval-r img:hover {
  opacity: 1;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.14);
}

@media (max-width: 720px) {
  .retrieval-r { grid-template-columns: repeat(5, 1fr); gap: 0.5rem; }
  .retrieval-r img { width: 100%; height: auto; aspect-ratio: 3 / 4; }
  .retrieval-q { width: 72px; height: 96px; }
}

/* hairline divider between sections */
.divider {
  max-width: var(--max-w);
  border: 0;
  border-top: 1px solid var(--hairline);
  margin: 0 auto;
}

/* ============================================================
   Paired-video gallery
   ============================================================ */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(540px, 1fr));
  gap: 1.5rem;
}

.pair {
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--hairline);
  overflow: hidden;
  box-shadow: 0 1px 2px rgba(0,0,0,0.02), 0 4px 16px rgba(0,0,0,0.04);
  transition: box-shadow 320ms var(--ease), transform 320ms var(--ease);
}

.pair:hover {
  box-shadow: 0 2px 4px rgba(0,0,0,0.03), 0 12px 32px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}

.cmp-stack {
  margin: 0;
  position: relative;
  background: #000;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  user-select: none;
  touch-action: none;
  cursor: ew-resize;
}

.cmp-stack video {
  display: none;            /* hidden source — pixels go to canvas */
}

.cmp-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.cmp-divider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.15);
  transform: translateX(-1px);
  pointer-events: none;
  z-index: 2;
}

.cmp-handle {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.28), 0 0 0 1px rgba(0, 0, 0, 0.08);
  transform: translate(-50%, -50%);
  pointer-events: none;     /* let pointer events fall through to the figure */
  display: flex;
  align-items: center;
  justify-content: center;
}
.cmp-handle::before {
  content: '◂  ▸';
  font-size: 11px;
  color: #333;
  letter-spacing: 1px;
  font-family: ui-monospace, monospace;
}

.cmp-stack .cap-left,
.cmp-stack .cap-right {
  position: absolute;
  top: 0.7rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.62rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.92);
  background: rgba(0, 0, 0, 0.45);
  padding: 0.35rem 0.6rem;
  border-radius: 4px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.cmp-stack .cap-left  { left: 0.8rem; }
.cmp-stack .cap-right { right: 0.8rem; }

/* ============================================================
   Pretraining figure (faithful HTML/SVG recreation of paper Fig.)
   ============================================================ */
.ptfig-intro {
  max-width: 760px;
  margin: 3rem auto 0.75rem;
  padding: 0 1rem;
  text-align: center;
  color: var(--text-soft);
  font-size: 1rem;
  line-height: 1.6;
}
.ptfig-intro strong {
  color: var(--text);
  font-weight: 600;
}

.ptfig {
  max-width: 920px;
  padding: 0 0.5rem;
  margin: 0 auto;
}

.ptfig-svg {
  width: 100%;
  height: auto;
  display: block;
  font-family: var(--font-sans);
}

/* SVG text classes use page typography for visual consistency */
.ptfig-lbl {
  font-family: var(--font-sans);
  font-size: 13px;
  fill: var(--text);
}

.ptfig-view-lbl {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 13px;
}

.ptfig-box-lbl {
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 17px;
  fill: var(--text);
}

.ptfig-box-lbl-sm {
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 13px;
  fill: var(--text);
}

.ptfig-small {
  font-family: var(--font-sans);
  font-size: 10px;
  fill: var(--muted);
}

.ptfig-loss-lbl {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 500;
  font-size: 16px;
  fill: var(--text);
}

/* ---------- Interaction-only: figure is fully static at rest ---------- */

/* Branch hover-dim: hovering MAE fades CL and vice versa */
.ptfig-svg .ptfig-mae,
.ptfig-svg .ptfig-cl {
  transition: opacity 240ms var(--ease, ease);
}
.ptfig-svg:has(.ptfig-mae:hover) .ptfig-cl,
.ptfig-svg:has(.ptfig-cl:hover) .ptfig-mae {
  opacity: 0.18;
}

/* Module hover: soft halo + cursor-help (signals the tooltip) */
.ptfig-svg .ptfig-mod {
  cursor: help;
}
.ptfig-svg .ptfig-mod > rect {
  transition: filter 240ms var(--ease, ease);
}
.ptfig-svg .ptfig-mod:hover > rect {
  filter: drop-shadow(0 0 5px rgba(40, 60, 100, 0.22))
          drop-shadow(0 6px 12px rgba(20, 24, 34, 0.08));
}

/* ============================================================
   Pretraining 3D globes (Apple-aesthetic)
   ============================================================ */
.ds-globes {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 56px;
  margin: 0 auto;
  /* break out of section padding so the bigger globes fit comfortably */
  margin-left: calc(50% - 50vw);
  margin-right: calc(50% - 50vw);
  padding: 0 24px;
}

.ds-globe-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.1rem;
  touch-action: none;
}

.ds-globe {
  display: block;
  overflow: visible;
  filter: drop-shadow(0 16px 28px rgba(0, 0, 0, 0.10))
          drop-shadow(0 4px 10px rgba(0, 0, 0, 0.06));
  cursor: grab;
}
.ds-globe:active { cursor: grabbing; }

.ds-sphere {
  stroke: rgba(0, 0, 0, 0.04);
  stroke-width: 1;
}

.ds-specular {
  pointer-events: none;
  mix-blend-mode: screen;
}

.ds-dot {
  cursor: pointer;
  transform-box: fill-box;
  transform-origin: center;
  transition: transform 220ms var(--ease), filter 220ms var(--ease);
  pointer-events: visiblePainted;
}
.ds-dot:hover {
  transform: scale(2.6);
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.35));
}

.ds-globe-label {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.ds-globe-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  letter-spacing: -0.01em;
}

.ds-globe-count {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.ds-tooltip {
  position: absolute;
  width: 96px;
  height: 128px;
  pointer-events: none;
  opacity: 0;
  transform: translate(-50%, 0);
  transition: opacity 160ms var(--ease);
  z-index: 10;
}

.ds-tooltip img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.16), 0 2px 6px rgba(0, 0, 0, 0.08);
  display: block;
}

@media (max-width: 720px) {
  .ds-globes { flex-direction: column; gap: 1.5rem; }
}

/* ============================================================
   Models spec sheet
   ============================================================ */
.models-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  max-width: var(--max-w);
  margin: 0 auto;
}

.model-card {
  background: var(--bg-card);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  padding: 1.5rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  transition: transform 220ms var(--ease), box-shadow 220ms var(--ease);
}

.model-card__head {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  color: inherit;
  text-decoration: none;
  cursor: pointer;
  border-radius: calc(var(--radius) - 4px);
  padding: 0.25rem 0;
  margin: -0.25rem 0;
  transition: background 200ms var(--ease);
}

.model-card__head:hover {
  background: rgba(0, 0, 0, 0.025);
}

.model-card__metric--linked {
  color: inherit;
  text-decoration: none;
  cursor: pointer;
  border-radius: 6px;
  padding: 0.25rem 0.4rem;
  margin: -0.25rem -0.4rem;
  transition: background 180ms var(--ease);
}

.model-card__metric--linked:hover {
  background: rgba(0, 0, 0, 0.04);
}

.model-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.03), 0 10px 28px rgba(0, 0, 0, 0.06);
}

.model-card__params {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.85rem;
  line-height: 1;
  color: var(--text);
  text-align: center;
  font-variant-numeric: tabular-nums;
}

.model-card__params-suffix {
  font-size: 0.55em;
  font-weight: 400;
  color: var(--muted);
  margin-left: 0.25rem;
  letter-spacing: 0.04em;
}

/* SVG vector-3D rotating model stack */
.model-card__stack-wrap {
  height: 190px;
  display: flex;
  align-items: flex-end;
  justify-content: center;
}

.model-card__svg3d {
  display: block;
  width: 130px;
  height: 170px;
  overflow: visible;
}

.model-card__arch {
  text-align: center;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.5;
  font-variant-numeric: tabular-nums;
}

.model-card__arch-flops { color: var(--text-soft); }
.model-card__arch-spec  { letter-spacing: 0.04em; }

.model-card__divider {
  height: 1px;
  background: var(--hairline);
  margin: 0.15rem 0 0.25rem;
}

.model-card__metrics {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.model-card__metric {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.model-card__metric-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 0.78rem;
}

.model-card__metric-label {
  color: var(--muted);
  letter-spacing: 0.04em;
}

.model-card__metric-value {
  color: var(--text);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}

.model-card__metric-unit {
  color: var(--muted);
  font-weight: 400;
  font-size: 0.85em;
  margin-left: 0.15rem;
}

.model-card__bar {
  height: 5px;
  background: var(--hairline);
  border-radius: 999px;
  overflow: hidden;
}

.model-card__bar-fill {
  height: 100%;
  background: var(--bar-color, var(--text));
  border-radius: inherit;
}

/* ============================================================
   Cross-image patch similarity
   4 columns: 3 vertical subject pairs (image + heatmap) + zoom.
   All elements 240px wide; 5 px / patch cell (48 × 5 = 240).
   ============================================================ */
.cross-showcase {
  display: grid;
  grid-template-columns: repeat(4, 288px) 144px;
  gap: 0.5rem;
  justify-content: center;
  align-items: start;
  /* break out of .section's narrow max-width so 4 big subjects + zoom fit */
  margin-left: calc(50% - 50vw);
  margin-right: calc(50% - 50vw);
}

.cross-subject {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.cross-img {
  position: relative;
  width: 288px;
  height: 384px;
  overflow: hidden;
  border-radius: var(--radius);
  cursor: crosshair;
  background: #0a0a0a;
}

.cross-img img {
  display: block;
  width: 288px;
  height: 384px;
  object-fit: cover;
  user-select: none;
  -webkit-user-drag: none;
}

.cross-grid-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right,  rgba(255,255,255,0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.14) 1px, transparent 1px);
  background-size: 6px 6px;
  mix-blend-mode: screen;
}

.cross-cell {
  position: absolute;
  opacity: 0;
  width: 6px;
  height: 6px;
  border: 1.5px solid rgba(255, 255, 255, 0.95);
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.6);
  pointer-events: none;
  z-index: 2;
  transition: left 60ms linear, top 60ms linear, opacity 120ms ease;
}

.cross-hm {
  display: block;
  width: 288px;
  height: 384px;
  border-radius: var(--radius);
  background: #0a0a0a;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

.cross-zoom-card {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  align-items: center;
}

.cross-zoom {
  width: 144px;
  height: 144px;
  border-radius: var(--radius);
  background-color: #0a0a0a;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

.cross-zoom-coord {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  text-align: center;
  white-space: nowrap;
}

.res-caption {
  max-width: 760px;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-soft);
  letter-spacing: 0;
  text-align: center;
  margin: 0 auto 1.25rem;
  padding: 0 1rem;
}

.res-caption strong {
  color: var(--text);
  font-weight: 600;
}

.res-caption-aside {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.74rem;
  opacity: 0.75;
}

/* ============================================================
   Citation card
   ============================================================ */
.cite {
  max-width: 880px;
  margin: 0 auto;
  padding: 2.5rem 2rem;
}

.cite-card {
  background: var(--bg-card);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  position: relative;
}

.cite-card pre {
  margin: 0;
  font-family: 'SF Mono', 'Menlo', 'Monaco', 'Consolas', monospace;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text-soft);
  white-space: pre-wrap;
  word-break: break-word;
}

.copy-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  padding: 0.45rem 0.85rem;
  background: transparent;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
  transition: background 200ms var(--ease), color 200ms var(--ease),
              border-color 200ms var(--ease);
}

.copy-btn:hover,
.copy-btn.copied {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  border-top: 1px solid var(--hairline);
  text-align: center;
  padding: 2rem 1.5rem 2.5rem;
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.footer p { margin: 0; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .section { padding: 1.75rem 1.25rem; }
  .gallery-grid { grid-template-columns: 1fr; }
  .models-grid { grid-template-columns: repeat(2, 1fr); }
  .cross-showcase { grid-template-columns: repeat(2, 240px); gap: 0.85rem; margin-left: auto; margin-right: auto; }
  .cross-zoom-card { grid-column: 1 / -1; flex-direction: row; gap: 1rem; justify-content: center; }
}

@media (max-width: 640px) {
  .hero { min-height: 520px; }
  .hero-actions { gap: 0.5rem; flex-wrap: wrap; justify-content: center; }
  .btn { padding: 0.65rem 1rem; font-size: 0.68rem; }
  .cmp-stack { aspect-ratio: 16 / 9; }
  .cite { padding: 1.75rem 1.25rem; }
  .cite-card { padding: 1.25rem 1rem; }
  .cite-card pre { font-size: 0.74rem; }
  .models-grid { grid-template-columns: 1fr; gap: 0.85rem; }
  .model-card { padding: 1.25rem 1rem; gap: 0.75rem; }
  .model-card__stack-wrap { height: 160px; }
  .model-card__svg3d { width: 110px; height: 144px; }
  .cross-showcase { grid-template-columns: 240px; margin-left: auto; margin-right: auto; }
  .cross-zoom-card { grid-column: 1; flex-direction: column; }
  .cross-img { cursor: pointer; }
  /* Method figure: too dense for narrow screens — let users swipe horizontally */
  .ptfig { overflow-x: auto; -webkit-overflow-scrolling: touch; padding-bottom: 0.5rem; }
  .ptfig-svg { min-width: 640px; }
  .ptfig-intro { font-size: 0.92rem; line-height: 1.55; }
  .res-caption { font-size: 0.92rem; line-height: 1.55; }
  /* Section header scales down */
  .section-header h2 { font-size: 1.7rem; }
}

/* Larger touch target on coarse pointers (phones, tablets) */
@media (pointer: coarse) {
  .cmp-handle { width: 44px; height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================================
   Scroll-spy section nav (fixed right side, dot strip)
   ============================================================ */
.scroll-nav {
  position: fixed;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 30;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 0.6rem 0.45rem;
  background: rgba(255, 255, 255, 0.62);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 999px;
  box-shadow: 0 4px 18px rgba(20, 24, 34, 0.06);
}
.scroll-dot {
  position: relative;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  text-decoration: none;
  color: var(--muted);
  transition: color 180ms var(--ease, ease), background 180ms var(--ease, ease);
}
.scroll-dot span {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.56rem;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
  opacity: 0.55;
  transition: opacity 180ms var(--ease, ease);
}
.scroll-dot::before {
  content: '';
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.35;
  transition: opacity 180ms var(--ease, ease), inset 180ms var(--ease, ease);
}
.scroll-dot:hover { color: var(--text); }
.scroll-dot:hover span { opacity: 1; }
.scroll-dot:hover::before { opacity: 0.6; }
.scroll-dot.is-active { color: var(--text); }
.scroll-dot.is-active span { opacity: 0; }
.scroll-dot.is-active::before { inset: 3px; opacity: 1; background: var(--text); }

@media (max-width: 640px) {
  .scroll-nav {
    right: 0.6rem;
    padding: 0.5rem 0.35rem;
    gap: 0.4rem;
  }
  .scroll-dot { width: 18px; height: 18px; }
  .scroll-dot span { font-size: 0.5rem; }
  .scroll-dot::before { inset: 5px; }
  .scroll-dot.is-active::before { inset: 2px; }
}

/* Keyboard focus on the compare slider */
.pair.cmp { outline: none; }
.pair.cmp:focus-visible {
  box-shadow: 0 0 0 3px rgba(40, 60, 100, 0.35),
              0 2px 4px rgba(0, 0, 0, 0.04),
              0 12px 32px rgba(0, 0, 0, 0.08);
}