/* ==========================================================================
   TANGO — ECCV 2026 project page
   Dark-first "night lab notebook" design.
   Two semantic accents, used consistently across text, chips, and charts:
     teal  = TANGO / on-manifold / realistic
     amber = drift / terminal points / baseline failures
   ========================================================================== */

/* ---------- Fonts (self-hosted, latin subsets) ---------- */
/* Computer Modern calligraphic (cmsy shapes, via KaTeX_Caligraphic, MIT):
   remapped to the Unicode script codepoints so mathcal L, J, N render
   exactly as pdfLaTeX's \mathcal in the paper. unicode-range keeps the
   face scoped to those three glyphs only. */
@font-face {
  font-family: 'CM Caligraphic';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('../fonts/CMCaligraphic.woff2') format('woff2');
  unicode-range: U+2112, U+1D4A5, U+1D4A9;
}
/* same face registered as italic: the glyphs are already slanted by design,
   so italic contexts must not add a synthetic oblique on top */
@font-face {
  font-family: 'CM Caligraphic';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url('../fonts/CMCaligraphic.woff2') format('woff2');
  unicode-range: U+2112, U+1D4A5, U+1D4A9;
}
@font-face {
  font-family: 'Source Serif 4';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url('../fonts/SourceSerif4-600.woff2') format('woff2');
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url('../fonts/Inter.woff2') format('woff2');
}

/* ---------- Tokens ---------- */
:root {
  color-scheme: dark;

  --bg: #0b0e12;
  --surface: #12161c;
  --surface-2: #171c24;
  --border: rgba(232, 236, 241, 0.08);
  --border-strong: rgba(232, 236, 241, 0.14);

  --text: #e8ecf1;
  --text-2: #a9b1bc;
  --muted: #8b949e;

  --accent: #5edac9;        /* teal for text / links */
  --accent-mark: #1fa694;   /* teal for marks (lines, rules, dots); validated on dark surfaces */
  --accent-dim: rgba(31, 166, 148, 0.10);
  --warn: #e8a66a;          /* amber for text */
  --warn-mark: #d0761f;     /* amber for marks */
  --warn-dim: rgba(208, 118, 31, 0.10);
  --jump: #e87ba4;          /* magenta for the correction jump (text) */
  --jump-mark: #d55181;     /* magenta for the correction jump (marks) */

  --grid: #232a33;          /* chart gridlines */
  --plate: #f4f3ef;         /* off-white plate for paper figures */
  --plate-ink: #1c2128;

  --serif: 'CM Caligraphic', 'Source Serif 4', Charter, Cambria, Georgia, serif;
  --sans: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: ui-monospace, 'SF Mono', 'Cascadia Code', Menlo, Consolas, monospace;

  --shell: 72rem;
  --prose: 46rem;
}

:root[data-theme='light'] {
  color-scheme: light;

  --bg: #fafaf8;
  --surface: #ffffff;
  --surface-2: #f1f1ee;
  --border: rgba(11, 15, 18, 0.09);
  --border-strong: rgba(11, 15, 18, 0.16);

  --text: #14181d;
  --text-2: #454c54;
  --muted: #5c646e;

  --accent: #0e7568;
  --accent-mark: #00937f;
  --accent-dim: rgba(0, 147, 127, 0.08);
  --warn: #a04d0b;
  --warn-mark: #c05617;
  --warn-dim: rgba(192, 86, 23, 0.08);
  --jump: #96305c;
  --jump-mark: #b03a6a;

  --grid: #e4e3dd;
  --plate: #ffffff;
  --plate-ink: #1c2128;
}

/* ---------- Reset & base ---------- */
*, *::before, *::after { box-sizing: border-box; }

[hidden] { display: none !important; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* subtle noise grain, dark theme only */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}
:root[data-theme='light'] body::after { display: none; }

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

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

::selection { background: rgba(44, 184, 165, 0.28); }

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.18;
  margin: 0;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

p { margin: 0 0 1.1rem; }

code, .mono { font-family: var(--mono); font-size: 0.9em; }

.math { font-family: var(--serif); font-style: italic; }
.math sub, .math sup { font-style: normal; font-size: 0.72em; }

/* LaTeX-style \hat{}: positioned circumflex that clears following scripts */
.hat { position: relative; }
.hat::after {
  content: 'ˆ';
  position: absolute;
  left: 58%;
  top: -0.06em;
  transform: translateX(-50%);
  font-style: normal;
  font-size: 0.85em;
  line-height: 1;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--surface-2);
  color: var(--text);
  padding: 0.5rem 1rem;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

/* ---------- Layout primitives ---------- */
.shell {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.prose { max-width: var(--prose); margin-inline: auto; }
.prose p {
  color: var(--text-2);
  text-align: justify;
  -webkit-hyphens: auto;
  hyphens: auto;
}
.prose strong { color: var(--text); font-weight: 600; }

section { padding: 4.5rem 0 1.5rem; }

.shell > .kicker, .shell > h2 { text-align: center; }

.kicker {
  font-size: 0.8125rem;
  font-weight: 600;
  font-family: var(--sans);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent);
  margin: 0 0 0.75rem;
}
.kicker--warn { color: var(--warn); }

section > .shell > h2 {
  font-size: clamp(1.5rem, 1.2rem + 1.2vw, 1.9rem);
  margin-bottom: 1.25rem;
}

.caption {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.55;
  margin-top: 0.75rem;
  max-width: 58rem;
  margin-inline: auto;
  text-align: center;
}
.caption strong { color: var(--text-2); font-weight: 600; }

/* ---------- Top nav ---------- */
.topnav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(9px) saturate(1.2);
  -webkit-backdrop-filter: blur(9px) saturate(1.2);
  border-bottom: 1px solid var(--border);
}
.topnav-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 52px;
}
.wordmark {
  display: inline-flex;
  align-items: center;
  font-weight: 600;
  color: var(--text);
  font-size: 0.9375rem;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.nav-mark {
  width: 0;
  height: 22px;
  margin-right: 0;
  opacity: 0;
  transform: translateY(5px);
  flex: none;
  transition: width 0.3s ease, margin-right 0.3s ease, opacity 0.3s ease, transform 0.3s ease;
}
.topnav.show-mark .nav-mark {
  width: 22px;
  margin-right: 0.45rem;
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .nav-mark { transition: none; }
  details summary::before { transition: none; }
}
@media (max-width: 640px) {
  .nav-mark { display: none; }
}
.wordmark:hover { text-decoration: none; }
.wordmark .tag { color: var(--muted); font-weight: 400; }
.nav-actions {
  display: flex;
  gap: 0.4rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(7px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}
.topnav.show-actions .nav-actions {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.nav-actions .btn {
  padding: 0.26rem 0.62rem;
  font-size: 0.8125rem;
  border-radius: 7px;
  gap: 0.4rem;
}
.nav-actions .btn svg { width: 13px; height: 13px; }
@media (prefers-reduced-motion: reduce) {
  .nav-actions { transition: none; }
}
@media (max-width: 1100px) {
  .nav-actions { display: none; }
}

.topnav-links {
  display: flex;
  gap: 0.25rem;
  margin-left: auto;
  overflow-x: auto;
  scrollbar-width: none;
}
.topnav-links::-webkit-scrollbar { display: none; }
.topnav-links.can-scroll {
  -webkit-mask-image: linear-gradient(90deg, #000 0, #000 calc(100% - 26px), transparent);
  mask-image: linear-gradient(90deg, #000 0, #000 calc(100% - 26px), transparent);
}
.topnav-links a {
  color: var(--text-2);
  font-size: 0.875rem;
  padding: 0.35rem 0.6rem;
  border-radius: 6px;
  white-space: nowrap;
}
.topnav-links a:hover { color: var(--text); text-decoration: none; background: var(--surface-2); }
.topnav-links a.active { color: var(--accent); text-decoration: underline; text-underline-offset: 5px; }
.theme-toggle {
  flex: none;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text-2);
  cursor: pointer;
}
.theme-toggle:hover { color: var(--text); border-color: var(--border-strong); }
.theme-toggle svg { width: 16px; height: 16px; }
:root:not([data-theme='light']) .icon-sun { display: none; }
:root[data-theme='light'] .icon-moon { display: none; }

/* ---------- Hero ---------- */
.accent-bar {
  height: 3px;
  background: linear-gradient(90deg, var(--accent-mark), var(--warn-mark));
}

.hero {
  position: relative;
  padding: 3.5rem 0 2rem;
  text-align: center;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background:
    radial-gradient(56rem 28rem at 22% -6%, rgba(31, 166, 148, 0.13), transparent 62%),
    radial-gradient(50rem 26rem at 82% -10%, rgba(208, 118, 31, 0.09), transparent 62%);
}
:root[data-theme='light'] .hero::before {
  background:
    radial-gradient(56rem 28rem at 22% -6%, rgba(0, 147, 127, 0.09), transparent 62%),
    radial-gradient(50rem 26rem at 82% -10%, rgba(192, 86, 23, 0.06), transparent 62%);
}
.hero-mark {
  width: 74px;
  height: 74px;
  margin: 0 auto 1.4rem;
  display: block;
}
.hero-kicker {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--muted);
  margin-bottom: 1rem;
}
.hero-kicker .pill {
  display: inline-block;
  border: 1px solid color-mix(in srgb, var(--accent-mark) 55%, transparent);
  border-radius: 999px;
  padding: 0.15rem 0.7rem;
  margin-right: 0.6rem;
  color: var(--accent);
  background: var(--accent-dim);
}
.hero h1 {
  font-size: clamp(1.9rem, 1.1rem + 3vw, 3.1rem);
  max-width: 56rem;
  margin-inline: auto;
  background: linear-gradient(118deg, var(--text) 0%, var(--text) 46%, var(--accent) 108%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}
@media (forced-colors: active) {
  .hero h1 { background: none; color: CanvasText; -webkit-text-fill-color: CanvasText; }
}
.hero-sub {
  margin: 1rem auto 0;
  font-size: 1.0625rem;
  color: var(--text-2);
  max-width: 46rem;
}
.hero-sub .abbr { color: var(--text); font-weight: 600; }

.authors {
  margin: 1.5rem auto 0;
  font-size: 1rem;
  color: var(--text-2);
  max-width: 52rem;
}
.authors a { color: var(--text); font-weight: 500; }
.authors a:hover { color: var(--accent); }
.authors sup { color: var(--muted); font-size: 0.72em; }
.affils {
  margin-top: 0.35rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
  margin-top: 1.5rem;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  color: var(--text);
  font-size: 0.9375rem;
  font-weight: 500;
  background: transparent;
  cursor: pointer;
}
.btn:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn svg { width: 15px; height: 15px; flex: none; color: var(--accent); }
.btn:hover svg { color: inherit; }
.btn--soon svg { color: var(--muted); }
.btn--soon { color: var(--muted); }
.btn--soon .soon {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0 0.3rem;
}

.thesis {
  margin: 2.4rem auto 0;
  max-width: 50rem;
  font-family: var(--serif);
  font-size: clamp(1.15rem, 1rem + 0.6vw, 1.35rem);
  line-height: 1.55;
  color: var(--text);
}
.thesis .tp {
  font-style: italic;
  color: var(--warn);
  border-bottom: 2px solid var(--warn-dim);
}
.thesis-sub {
  margin: 1rem auto 0;
  max-width: 46rem;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text-2);
}

/* ---------- Hero teaser (drift strip) ---------- */
.teaser {
  margin-top: 2.5rem;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  padding: 1.1rem 1.1rem 0.9rem;
}
.teaser-head {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.9rem;
}
.teaser-title { font-size: 0.9375rem; font-weight: 600; color: var(--text); }
.teaser-note { font-size: 0.8125rem; color: var(--muted); margin-left: auto; }

.race-rows { display: grid; gap: 0.8rem; }
.race-row {
  display: grid;
  grid-template-columns: 188px minmax(0, 520px);
  gap: 1rem;
  align-items: center;
  justify-content: center;
}
.race-label { min-width: 0; }
.race-name { font-size: 0.9rem; font-weight: 600; color: var(--text); line-height: 1.3; }
.race-name .who { display: block; font-size: 0.78rem; font-weight: 500; color: var(--muted); }
.race-chips { display: flex; flex-wrap: wrap; gap: 0.3rem; margin-top: 0.4rem; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
  font-size: 0.75rem;
  font-weight: 500;
  border-radius: 5px;
  padding: 0.08rem 0.45rem;
  white-space: nowrap;
}
.chip--good { background: var(--accent-dim); color: var(--accent); }
.chip--bad { background: var(--warn-dim); color: var(--warn); }

/* ---------- Frame viewer (the reusable "clip" scrubber) ---------- */
.frames {
  position: relative;
  border-radius: 9px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #000;
}
/* No-JS / pre-JS: horizontal snap strip */
.frames-track {
  display: flex;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  gap: 2px;
}
.frames-track img {
  width: 68%;
  flex: none;
  scroll-snap-align: start;
}
/* JS upgrade: stacked single-frame viewer */
.clip.is-ready .frames-track {
  display: grid;
  overflow: visible;
  gap: 0;
}
.clip.is-ready .frames-track img {
  grid-area: 1 / 1;
  width: 100%;
  visibility: hidden;
}
.clip.is-ready .frames-track img.on { visibility: visible; }
.clip.is-ready .frames { cursor: crosshair; touch-action: pan-y; }

.clip-ui {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-top: 0.55rem;
}
.clip-ui input[type='range'] { flex: 1; }
.timecode {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--text-2);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.1rem 0.5rem;
  white-space: nowrap;
  min-width: 4.6rem;
  text-align: center;
}

input[type='range'] {
  appearance: none;
  -webkit-appearance: none;
  height: 24px;
  background: transparent;
  cursor: pointer;
  margin: 0;
}
input[type='range']::-webkit-slider-runnable-track {
  height: 5px;
  border-radius: 3px;
  background: var(--grid);
  border: 1px solid var(--border-strong);
}
input[type='range']::-moz-range-track {
  height: 5px;
  border-radius: 3px;
  background: var(--grid);
  border: 1px solid var(--border-strong);
}
input[type='range']::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--accent-mark);
  border: 2px solid var(--bg);
}
input[type='range']::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-mark);
  border: 2px solid var(--bg);
}

/* segment axis under shared sliders */
.seg-axis {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.15rem;
}
.seg-axis span { text-align: center; }
.seg-axis span.on { color: var(--accent); }

/* ---------- Callout ---------- */
.callout {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-mark);
  background: var(--surface);
  border-radius: 0 10px 10px 0;
  padding: 1rem 1.25rem;
  margin: 1.75rem auto;
  max-width: var(--prose);
}
.callout .term {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 600;
  color: var(--text);
}
.callout p { margin: 0; color: var(--text-2); font-size: 0.9875rem; }

/* ---------- Method steps ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin: 2rem 0;
}
.step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.1rem 1.2rem;
}
.step-n {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--accent);
  margin-bottom: 0.5rem;
}
.step h3 { font-size: 1.0625rem; font-family: var(--sans); font-weight: 600; margin-bottom: 0.4rem; }
.step p { margin: 0; font-size: 0.9375rem; color: var(--text-2); }

/* loss cards */
.losses {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1.25rem 0;
}
.loss {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  background: var(--surface);
}
.loss h4 {
  margin: 0 0 0.3rem;
  font-size: 0.9375rem;
  font-weight: 600;
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
}
.loss h4 .math { color: var(--accent); font-size: 1.05em; }
.loss p { margin: 0; font-size: 0.875rem; color: var(--text-2); }

.equation {
  max-width: 46rem;
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.15rem;
  text-align: center;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.1rem 1rem;
  margin: 1.5rem auto 0.5rem;
  overflow-x: auto;
}
.equation sub, .equation sup { font-style: normal; font-size: 0.7em; }


/* ---------- details / disclosure ---------- */
details {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  margin: 1rem 0;
}
details summary {
  cursor: pointer;
  padding: 0.8rem 1.1rem;
  font-weight: 500;
  font-size: 0.9375rem;
  color: var(--text);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
details summary::-webkit-details-marker { display: none; }
details summary::before {
  content: '';
  width: 7px;
  height: 7px;
  border-right: 1.5px solid var(--muted);
  border-bottom: 1.5px solid var(--muted);
  transform: rotate(-45deg);
  transition: transform 0.18s;
  flex: none;
}
details[open] summary::before { transform: rotate(45deg); }
.details-body { padding: 0.2rem 1.1rem 1.1rem; }
.details-body p { font-size: 0.9375rem; color: var(--text-2); }

/* ---------- Charts ---------- */
.viz-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.25rem 0.9rem;
  margin: 1.75rem 0 0.5rem;
}
.viz-title { font-size: 1rem; font-weight: 600; margin: 0 0 0.1rem; font-family: var(--sans); }
.viz-sub { font-size: 0.8425rem; color: var(--muted); margin: 0 0 0.9rem; }
.viz-wrap { overflow-x: auto; }
.viz-wrap svg { display: block; width: 100%; height: auto; min-width: 560px; }

.viz-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1.1rem;
  margin-top: 0.6rem;
  font-size: 0.8125rem;
  color: var(--text-2);
}
.viz-legend .key {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}
.viz-legend .swatch {
  width: 14px;
  height: 3px;
  border-radius: 2px;
  display: inline-block;
  flex: none;
}
.viz-legend .dotkey {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: inline-block;
  flex: none;
}

svg .axis-text { font-family: var(--sans); font-size: 12px; fill: var(--muted); }
svg .axis-label { font-family: var(--sans); font-size: 12.5px; fill: var(--muted); }
svg .end-label { font-family: var(--sans); font-size: 12.5px; font-weight: 600; fill: var(--text); }
svg .end-sub { font-family: var(--sans); font-size: 11.5px; fill: var(--muted); }
svg .gridline { stroke: var(--grid); stroke-width: 1; }
svg .series-tango { stroke: var(--accent-mark); }
svg .series-base { stroke: var(--warn-mark); }
svg .dot-tango { fill: var(--accent-mark); stroke: var(--surface); stroke-width: 2; }
svg .dot-base { fill: var(--warn-mark); stroke: var(--surface); stroke-width: 2; }
svg .dot-ctx { fill: var(--muted); stroke: var(--surface); stroke-width: 2; }
svg .bubble-ctx { fill: var(--muted); fill-opacity: 0.35; stroke: var(--muted); stroke-width: 1; }
svg .bubble-tango { fill: var(--accent-mark); fill-opacity: 0.55; stroke: var(--accent-mark); stroke-width: 1.5; }
svg .anno { font-family: var(--sans); font-size: 12px; fill: var(--warn); font-weight: 600; }
svg .anno-line { stroke: var(--warn-mark); stroke-width: 1; }
svg .hit { fill: transparent; }
svg .hit:hover { fill: rgba(139, 148, 158, 0.06); }

.viz-tip {
  position: fixed;
  z-index: 60;
  pointer-events: none;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 0.5rem 0.7rem;
  font-size: 0.8125rem;
  color: var(--text);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
  max-width: 260px;
  display: none;
}
.viz-tip b { font-weight: 600; }
.viz-tip .row { display: flex; gap: 0.6rem; justify-content: space-between; }
.viz-tip .row span:first-child { color: var(--text-2); }

/* ---------- Comparison (drift race) ---------- */
.tabs {
  display: flex;
  gap: 0.15rem;
  border-bottom: 1px solid var(--border);
  margin: 1.5rem 0 1.25rem;
  overflow-x: auto;
}
.tab {
  appearance: none;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-2);
  font: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 0.5rem 0.9rem;
  cursor: pointer;
  white-space: nowrap;
  margin-bottom: -1px;
}
.tab:first-child { margin-left: auto; }
.tab:last-child { margin-right: auto; }
.tab:hover { color: var(--text); }
.tab[aria-selected='true'] { color: var(--accent); border-bottom-color: var(--accent-mark); }

.race-panel[hidden] { display: none; }
.race-prompt {
  font-size: 0.9rem;
  color: var(--muted);
  font-style: italic;
  margin: 0 0 1rem;
  text-align: center;
}
.race-row--ours .race-name { color: var(--accent); }
.race-shared {
  margin-top: 1.1rem;
  display: grid;
  gap: 0.1rem;
  max-width: 724px;
  margin-inline: auto;
}

/* ---------- Gallery ---------- */
.mode-tabs { margin-top: 1.75rem; }
.gallery-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
  min-width: 0;
}
.card .frames { position: relative; }
.input-thumb {
  position: absolute;
  left: 8px;
  top: 8px;
  z-index: 2;
  width: 26%;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.45);
}
.input-thumb img { width: 100%; }
.input-thumb .tag {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(0, 0, 0, 0.55);
  padding: 0.06rem 0.3rem;
  text-align: center;
}
.card-prompt {
  margin: 0.7rem 0 0.2rem;
  font-size: 0.875rem;
  color: var(--text-2);
  line-height: 1.5;
}
.card-prompt::before { content: '“'; color: var(--muted); }
.card-prompt::after { content: '”'; color: var(--muted); }
.card-note { font-size: 0.8125rem; color: var(--muted); margin: 0.35rem 0 0; }

/* ---------- Tables ---------- */
.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
}
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.875rem;
}
th, td {
  padding: 0.55rem 0.8rem;
  text-align: center;
  white-space: nowrap;
  border-bottom: 1px solid var(--border);
}
thead th {
  background: var(--surface-2);
  color: var(--text-2);
  font-weight: 600;
  font-size: 0.8125rem;
  position: sticky;
  top: 0;
}
th:first-child, td:first-child {
  text-align: left;
  position: sticky;
  left: 0;
  background: var(--surface);
  z-index: 1;
}
thead th:first-child { background: var(--surface-2); z-index: 2; }
tbody tr:last-child td { border-bottom: none; }
td { color: var(--text-2); font-variant-numeric: tabular-nums; }
tbody th[scope='row'] { font-weight: 400; color: var(--text-2); }
td.best { color: var(--text); font-weight: 600; }
td.second { text-decoration: underline; text-underline-offset: 3px; }
tr.ours td, tr.ours th {
  background: var(--accent-dim);
  color: var(--text);
}
tr.ours td:first-child, tr.ours th:first-child {
  box-shadow: inset 3px 0 0 var(--accent-mark);
  font-weight: 600;
  background: color-mix(in srgb, var(--surface) 86%, var(--accent-mark));
}
.table-groups th:nth-child(2n+3), .table-groups td:nth-child(2n+3) {
  border-left: 1px solid var(--border);
}

.table-note {
  font-size: 0.8125rem;
  color: var(--muted);
  margin-top: 0.6rem;
  max-width: 58rem;
  margin-inline: auto;
  text-align: center;
}

/* ---------- Failures ---------- */
.failure-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1.75rem;
}
.failure-chips { display: flex; gap: 0.4rem; margin: 0.7rem 0 0.5rem; }

/* ---------- Citation ---------- */
.cite-box {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-top: 1.25rem;
}
.cite-box pre {
  margin: 0;
  padding: 1.25rem 1.4rem;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.8425rem;
  line-height: 1.6;
  color: var(--text-2);
}
.copy-btn {
  position: absolute;
  top: 0.7rem;
  right: 0.7rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font: inherit;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-2);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 0.3rem 0.7rem;
  cursor: pointer;
}
.copy-btn:hover { color: var(--text); border-color: var(--border-strong); }
.copy-btn.copied { color: var(--accent); border-color: var(--accent-mark); }

.ack {
  font-size: 0.875rem;
  color: var(--muted);
  max-width: var(--prose);
  margin: 2rem auto 0;
  text-align: center;
}

/* ---------- Footer ---------- */
footer {
  border-top: 1px solid var(--border);
  margin-top: 4.5rem;
  padding: 2rem 0 2.5rem;
  font-size: 0.8425rem;
  color: var(--muted);
  text-align: center;
}
footer a { color: var(--text-2); }
footer .foot-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 1.2rem; margin-bottom: 0.8rem; }

/* ---------- Reveal on scroll ---------- */
html.js .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
html.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html.js .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- Manifold SVG ---------- */
.manifold-fig {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.4rem 1.5rem 1rem;
  margin: 2rem 0 0.5rem;
}
.manifold-scroll { overflow-x: auto; }
.manifold-fig svg { width: 100%; height: auto; display: block; min-width: 560px; }
.arch-fig svg { min-width: 760px; }
svg .arch-box { fill: var(--surface); stroke-width: 1.5; }
svg .arch-box--adapted { stroke: var(--accent-mark); }
svg .arch-box--frozen { stroke: var(--muted); stroke-opacity: 0.55; }
svg .arch-title { font-family: var(--serif); font-style: italic; font-size: 24px; fill: var(--text); }
svg .arch-sub { font-family: var(--sans); font-size: 11px; fill: var(--muted); }
svg .arch-badge-t { font-family: var(--sans); font-size: 10.5px; font-weight: 600; letter-spacing: 0.04em; }
svg .arch-badge-t.adapted { fill: var(--accent); }
svg .arch-badge-t.frozen { fill: var(--muted); }
svg .arch-frame { fill: var(--surface-2); stroke: var(--muted); stroke-opacity: 0.6; stroke-width: 1.3; }
svg .arch-frame--adapted { stroke: var(--accent-mark); stroke-opacity: 1; }
svg .arch-noise { stroke: var(--muted); stroke-opacity: 0.6; stroke-width: 1.3; }
svg .arch-noise--warn { stroke: var(--warn-mark); stroke-opacity: 1; }
svg .arch-flow { stroke: var(--muted); stroke-width: 1.6; fill: none; }
svg .arch-flow--warn { stroke: var(--warn-mark); }
svg .arch-loop { stroke: var(--accent-mark); stroke-width: 1.8; stroke-dasharray: 7 6; fill: none; }
svg .arch-pill { fill: var(--surface); stroke-width: 1.5; }
svg .arch-pill--warn { stroke: var(--warn-mark); }
svg .arch-pill--reg { stroke: var(--muted); stroke-opacity: 0.55; }
svg .arch-pill--j { stroke: var(--accent-mark); }
svg .arch-pill-t { font-family: var(--serif); font-style: italic; font-size: 16px; }
svg .arch-pill-t.warn { fill: var(--warn); }
svg .arch-pill-t.reg { fill: var(--text-2); }
svg .arch-pill-t.j { fill: var(--accent); }
svg .mani-blob { fill: var(--accent-mark); fill-opacity: 0.07; stroke: var(--accent-mark); stroke-opacity: 0.35; stroke-width: 1.5; }
svg .mani-label { font-family: var(--sans); font-size: 12.5px; fill: var(--muted); }
svg .mani-var { font-family: var(--serif); font-style: italic; font-size: 14px; fill: var(--text); }
svg .traj-ok { stroke: var(--accent-mark); stroke-width: 2; fill: none; }
svg .traj-bad { stroke: var(--warn-mark); stroke-width: 2; fill: none; }
svg .traj-fix { stroke: var(--jump-mark); stroke-width: 2; stroke-dasharray: 6 5; fill: none; }
svg .pt-ok { fill: var(--accent-mark); }
svg .pt-bad { fill: var(--warn-mark); }
svg .pt-ring { fill: none; stroke: var(--warn-mark); stroke-width: 1.5; }
svg .region-bad { fill: none; stroke: var(--warn-mark); stroke-opacity: 0.55; stroke-width: 1.3; stroke-dasharray: 5 5; }
svg .mani-anno { font-family: var(--sans); font-size: 12px; font-weight: 600; }
svg .mani-anno.bad { fill: var(--warn); }
svg .mani-anno.ok { fill: var(--accent); }
svg .mani-anno.jump { fill: var(--jump); }
svg .hat-mark { stroke: var(--text); stroke-width: 1.3; fill: none; stroke-linecap: round; stroke-linejoin: round; }

@media (prefers-reduced-motion: no-preference) {
  .manifold-fig.animate .draw {
    stroke-dasharray: var(--len, 600);
    stroke-dashoffset: var(--len, 600);
    animation: draw 1.2s ease-out forwards;
  }
  .manifold-fig.animate .fade-in {
    opacity: 0;
    animation: fadein 0.6s ease-out forwards;
  }
  @keyframes draw { to { stroke-dashoffset: 0; } }
  @keyframes fadein { to { opacity: 1; } }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .steps { grid-template-columns: 1fr; }
  .gallery-grid, .failure-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 1rem; }
  section { padding: 3.25rem 0 1rem; }
  .losses { grid-template-columns: 1fr; }
  .race-row, .race-panel .race-row {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }
  .race-label { display: flex; align-items: baseline; gap: 0.6rem; flex-wrap: wrap; }
  .race-chips { margin-top: 0; }
  .hero { padding-top: 2.5rem; }
  .topnav-links a { padding: 0.35rem 0.45rem; }
  .cite-box pre { padding-right: 5rem; }
}

@media print {
  :root {
    color-scheme: light;
    --bg: #ffffff;
    --surface: #ffffff;
    --surface-2: #f2f2f0;
    --border: rgba(0, 0, 0, 0.18);
    --border-strong: rgba(0, 0, 0, 0.32);
    --text: #000000;
    --text-2: #262b30;
    --muted: #4a5158;
    --accent: #0e7568;
    --accent-mark: #00937f;
    --accent-dim: rgba(0, 147, 127, 0.08);
    --warn: #a04d0b;
    --warn-mark: #c05617;
    --warn-dim: rgba(192, 86, 23, 0.08);
    --grid: #dddbd4;
    --plate: #ffffff;
  }
  .topnav, .theme-toggle, body::after { display: none; }
  body { background: #fff; }
  html.js .reveal { opacity: 1 !important; transform: none !important; }
  .hero h1 { background: none; color: var(--text); -webkit-text-fill-color: initial; }
  .hero::before { display: none; }
  table { font-size: 6.5pt; }
  th, td { padding: 2pt 4pt; white-space: normal; }
}