/* ============================================================
   FPL blog — warm palette inspired by pi.website/research/memory:
   cream #f3eee3 background · warm brown ink #2d2719 / #5c5240
   terracotta accent #bb7a4f / #8f5a31 (the --sky-* vars now hold warm tones)
   ============================================================ */

/* warm (pi.website-inspired) — the default */
:root, :root[data-theme="warm"] {
  --bg: #f3eee3;
  --bg-soft: #ece5d6;
  --ink: #2d2719;
  --ink-soft: #5c5240;
  --ink-deep: #211b10;
  --sky: #bb7a4f;
  --sky-deep: #8f5a31;
  --sky-mid: #cf9d70;
  --sky-light: #e4d5ba;
  --sky-pale: #f3eee3;
  --line: rgba(45, 39, 25, 0.14);
  --muted: 92, 82, 64;
  --stripe: 170, 138, 95;
}

/* blue (flappingairplanes-inspired) — the original */
:root[data-theme="blue"] {
  --bg: #d7efff;
  --bg-soft: #eef8ff;
  --ink: #1a1a2e;
  --ink-soft: #2c3e50;
  --ink-deep: #0a1220;
  --sky: #5dade2;
  --sky-deep: #3a8ecb;
  --sky-mid: #73b8ee;
  --sky-light: #b2dcfa;
  --sky-pale: #d7efff;
  --line: rgba(10, 18, 32, 0.12);
  --muted: 44, 62, 80;
  --stripe: 93, 173, 226;
}

:root {
  --radius: 14px;
  --font-body: "Inter", system-ui, -apple-system, sans-serif;
  --font-head: "Space Grotesk", var(--font-body);
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------------- footer ---------------- */

.site-footer {
  margin-top: 96px;
  padding: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  font-size: 0.85rem;
  color: rgba(var(--muted), 0.55);
}

.footer-logo { width: 22px; height: 22px; border-radius: 6px; opacity: 0.9; }

/* ---------------- layout ---------------- */

main { padding: 0 20px; }

.prose, .hero {
  max-width: 720px;
  margin: 0 auto;
}

.wide { max-width: 980px; margin-left: auto; margin-right: auto; }

section.prose { margin-top: 64px; }

/* ---------------- hero ---------------- */

.hero {
  text-align: center;
  padding: 80px 0 28px;
}

.hero h1 {
  font-family: var(--font-head);
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  line-height: 1.08;
  margin: 0 0 18px;
  color: var(--ink-deep);
  letter-spacing: -0.015em;
}

.hero-sub { color: var(--sky-deep); }

.authors { font-size: 0.95rem; color: var(--ink-soft); margin: 0; }
.authors .affil { color: rgba(var(--muted), 0.65); }
.authors-affil { font-size: 0.92rem; color: rgba(var(--muted), 0.75); margin: 5px 0 0; }
.authors-note { font-size: 0.75rem; color: rgba(var(--muted), 0.5); margin: 4px 0 0; }

.hero-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--sky-deep);
  margin: 14px 0 24px;
}

.hero-links { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; margin-bottom: 28px; }

.btn {
  display: inline-block;
  padding: 9px 20px;
  border-radius: 999px;
  background: var(--ink-deep);
  color: #fff;
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 600;
  transition: background 0.15s ease, transform 0.15s ease;
}

.btn:hover { background: var(--sky-deep); transform: translateY(-1px); }

/* ---------------- typography ---------------- */

.prose h2 {
  font-family: var(--font-head);
  font-size: 1.85rem;
  line-height: 1.2;
  margin: 0 0 18px;
  color: var(--ink-deep);
  letter-spacing: -0.01em;
}

.prose h3 {
  font-family: var(--font-head);
  font-size: 1.2rem;
  margin: 34px 0 10px;
  color: var(--ink-deep);
}

.prose p { margin: 0 0 18px; text-align: justify; text-justify: inter-word; hyphens: auto; }

.prose strong { color: var(--ink-deep); }

.prose a { color: var(--sky-deep); }

blockquote.pull {
  margin: 32px 0;
  padding: 22px 26px;
  border-left: 4px solid var(--sky);
  background: rgba(255, 255, 255, 0.55);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 1.12rem;
  line-height: 1.55;
  color: var(--ink-deep);
}

.try-hint { font-weight: 600; color: var(--sky-deep); }

/* ---------------- media frames + placeholders ---------------- */

figure.media { margin: 36px auto; }

.media-frame {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  min-height: 120px;
}

.media-frame video,
.media-frame img {
  display: block;
  width: 100%;
  height: auto;
}

/* dashed slot shown until the media file exists */
.media-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  text-align: center;
  padding: 48px 20px;
  font-size: 0.95rem;
  color: var(--ink-soft);
  background:
    linear-gradient(rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0.5)),
    repeating-linear-gradient(-45deg, transparent 0 14px, rgba(var(--stripe), 0.13) 14px 28px);
  border: 2px dashed var(--sky-light);
  border-radius: var(--radius);
}

.media-placeholder code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--sky-deep);
}

.media-frame.loaded .media-placeholder { display: none; }

/* placeholders for empty frames keep aspect */
.media-frame:not(.loaded) { aspect-ratio: 16 / 9; }
.media-frame:not(.loaded) video,
.media-frame:not(.loaded) img { position: absolute; inset: 0; }

figcaption {
  margin-top: 12px;
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--ink-soft);
  text-align: center;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------------- prompt blocks ---------------- */

.prompt-block {
  background: var(--ink-deep);
  color: #e8eef5;
  border-radius: var(--radius);
  padding: 18px 22px;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.7;
  overflow-x: auto;
  margin: 24px 0;
}

.prompt-block.slim { margin: 18px auto; max-width: 720px; }

.prompt-block .pk { color: var(--sky-mid); font-weight: 600; }
.prompt-block .pv { color: #ffd479; }

/* ---------------- results chart ---------------- */

.chart-card {
  margin: 36px auto;
  padding: 26px 28px 18px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.chart-title {
  font-family: var(--font-head);
  font-weight: 600;
  margin: 0 0 18px;
  color: var(--ink-deep);
}

.bar-row {
  display: grid;
  grid-template-columns: 200px 1fr 44px;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
  font-size: 0.88rem;
}

.bar-label { color: var(--ink-soft); text-align: right; }

.bar-track {
  background: rgba(10, 18, 32, 0.06);
  border-radius: 999px;
  height: 18px;
  overflow: hidden;
}

.bar {
  width: var(--w);
  height: 100%;
  border-radius: 999px;
  background: var(--sky-light);
  animation: grow 0.9s ease both;
}

/* paper Fig. 3 method colors */
.bar.bc  { background: var(--m-bc); }
.bar.fbc { background: var(--m-fbc); }
.bar.spp { background: var(--m-spp); }
.bar.spc { background: var(--m-spc); }
.bar.fpl { background: var(--m-fpl); }

.bar-row.ours .bar-label,
.bar-row.ours .bar-val { font-weight: 700; color: var(--ink-deep); }

.bar-val { font-family: var(--font-mono); font-size: 0.8rem; }

@keyframes grow { from { width: 0; } }

.chart-card figcaption { margin-top: 14px; }

/* ---------------- widgets ---------------- */

.widget {
  margin: 36px auto;
  padding: 26px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 20px;
  max-width: 820px;
}

.widget figure.media { margin: 18px 0 0; }
.widget figcaption { margin-top: 10px; }

/* tabs (comparison tasks) */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
  justify-content: center;
}

.tab {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab:hover { border-color: var(--sky); color: var(--sky-deep); }

.tab.active {
  background: var(--ink-deep);
  border-color: var(--ink-deep);
  color: #fff;
}

/* side-by-side grid */
#compare-widget { max-width: 980px; }

.compare-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: center;
}

.compare-grid figure.media { margin: 0; }

.vs-badge {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.85rem;
  color: #fff;
  background: var(--sky-deep);
  border-radius: 999px;
  padding: 8px 12px;
}

.vs-label {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--ink-soft);
}

.ours-label { color: var(--sky-deep); }

/* baseline selector: clean pill toggle (replaces the native dropdown) */
.cmp-toggle {
  display: inline-flex;
  border-radius: 999px;
  background: rgba(10, 18, 32, 0.05);
  padding: 3px;
  gap: 2px;
}

.cmp-base-btn {
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 6px 14px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  transition: background 0.14s ease, color 0.14s ease;
}
.cmp-base-btn:hover { color: var(--sky-deep); }
.cmp-base-btn.active {
  background: var(--ink-deep);
  color: #fff;
  box-shadow: 0 1px 4px rgba(10, 18, 32, 0.2);
}

/* per-task caption under the comparison */
.cmp-caption {
  max-width: 760px;
  margin: 20px auto 0;
  padding: 14px 22px;
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-style: italic;
  line-height: 1.55;
  color: var(--ink-soft);
  text-align: center;
}

/* per-bowl selector shown only for the cube comparison */
.cmp-bowls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin: -8px 0 20px;
}
.cmp-bowls[hidden] { display: none; }
.cmp-bowls-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  margin-right: 4px;
}

/* steerability bowls */
.steer-controls { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }

.bowl-btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: 999px;
  border: 2px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.15s ease;
}

.bowl-dot { width: 14px; height: 14px; border-radius: 50%; display: inline-block; }
.bowl-btn.blue .bowl-dot { background: #3b82d6; }
.bowl-btn.orange .bowl-dot { background: #e8893a; }
.bowl-btn.yellow .bowl-dot { background: #e5c84a; }

.bowl-btn:hover { transform: translateY(-1px); border-color: var(--sky); }
.bowl-btn.active { border-color: var(--ink-deep); background: var(--ink-deep); color: #fff; }

/* steerability animated schematic */
.steer-anim {
  position: relative;
  height: 150px;
  margin: 8px auto 4px;
  max-width: 560px;
}

.steer-gripper {
  position: absolute;
  top: 6px;
  left: 0;
  width: 44px;
  transition: transform 0.7s cubic-bezier(0.45, 0, 0.25, 1);
  will-change: transform;
}

.gripper-arm {
  width: 6px;
  height: 26px;
  margin: 0 auto;
  background: var(--ink-soft);
  border-radius: 3px;
}

.gripper-claw {
  width: 34px;
  height: 12px;
  margin: 0 auto;
  border: 4px solid var(--ink-soft);
  border-top: none;
  border-radius: 0 0 10px 10px;
}

.steer-cube {
  position: absolute;
  top: 32px;
  left: 50%;
  width: 18px;
  height: 18px;
  margin-left: -9px;
  border-radius: 4px;
  background: var(--ink-deep);
  transition: transform 0.55s cubic-bezier(0.5, 0, 0.8, 0.6);
  will-change: transform;
}

.steer-cube.drop { transform: translateY(62px) rotate(8deg); }

.steer-bowls {
  position: absolute;
  bottom: 26px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-around;
}

.steer-bowl {
  width: 64px;
  height: 26px;
  border-radius: 0 0 40px 40px;
  border: 3px solid transparent;
  border-top: none;
  transition: transform 0.2s ease;
}

.steer-bowl.blue   { background: #3b82d6; }
.steer-bowl.orange { background: #e8893a; }
.steer-bowl.yellow { background: #e5c84a; }

.steer-bowl.target { transform: scale(1.12); box-shadow: 0 0 0 3px var(--bg-soft), 0 0 0 5px var(--sky); }

.steer-table {
  position: absolute;
  bottom: 18px;
  left: 4%;
  right: 4%;
  height: 4px;
  border-radius: 2px;
  background: var(--ink-soft);
  opacity: 0.55;
}

/* highlight the prompt value that just changed */
@keyframes flash {
  0% { background: var(--sky-deep); border-radius: 4px; }
  100% { background: transparent; }
}

#steer-prompt.flash { animation: flash 0.9s ease; }

/* compositionality animated schematic */
.compose-anim {
  max-width: 460px;
  margin: 14px auto 0;
}

#compose-marker {
  transform: translate(162px, 85px); /* starts on the left-slow cluster */
  will-change: transform;
}

#compose-gap { stroke: var(--sky-deep); transition: fill 0.4s ease, stroke 0.4s ease; }
#compose-gap-label { fill: var(--sky-deep); }

#compose-gap.lit {
  fill: rgba(232, 137, 58, 0.1);
  stroke: #e8893a;
}

/* evaluation rollouts (FPL + single-pref.) fade in on the composed combo */
#compose-results {
  opacity: 0;
  transition: opacity 0.7s ease 0.35s;
}

#compose-results.show { opacity: 1; }

/* compositionality segmented controls */
.compose-controls {
  display: flex;
  justify-content: center;
  gap: 28px;
  flex-wrap: wrap;
}

.seg { display: flex; align-items: center; gap: 8px; }

.seg-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

.seg-btn {
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 8px 16px;
  border: 2px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.15s ease;
}

.seg-btn:first-of-type { border-radius: 999px 0 0 999px; }
.seg-btn:last-of-type { border-radius: 0 999px 999px 0; margin-left: -2px; }
.seg-btn.active { background: var(--ink-deep); border-color: var(--ink-deep); color: #fff; }

.compose-status {
  text-align: center;
  margin: 16px 0 0;
  min-height: 28px;
  font-size: 0.9rem;
  font-weight: 600;
}

.compose-status .badge {
  display: inline-block;
  padding: 5px 14px;
  border-radius: 999px;
  background: var(--sky);
  color: #fff;
  animation: pop 0.25s ease;
}

.compose-status .badge.in-data { background: rgba(var(--muted), 0.5); }

/* 2x2 grid of the four sim clips; the selected peg×speed cell is focused */
.compose-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  max-width: 340px;
  margin: 18px auto 0;
}
.compose-cell { margin: 0; }
.compose-cell figcaption {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-soft);
}
.compose-cell .media-frame {
  border-radius: 10px;
  transition: box-shadow 0.18s ease, opacity 0.18s ease, transform 0.18s ease;
}
.compose-cell .media-frame:not(.loaded) { aspect-ratio: 1 / 1; }
.compose-cell video, .compose-cell img { image-rendering: auto; }

/* non-selected cells are dimmed but still visible */
.compose-cell { opacity: 0.4; transition: opacity 0.18s ease; }
.compose-cell.active { opacity: 1; }
.compose-cell.active .media-frame {
  box-shadow: 0 0 0 2px var(--bg-soft), 0 0 0 4px var(--sky);
  transform: scale(1.02);
}
.compose-cell.active figcaption { color: var(--ink-deep); font-weight: 600; }

.compose-cell-tag {
  display: inline-block;
  background: var(--sky-deep);
  color: #fff;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.62rem;
  padding: 1px 6px;
  border-radius: 999px;
  margin-left: 2px;
  vertical-align: middle;
}

@keyframes pop { from { transform: scale(0.85); opacity: 0; } }

/* ---------------- collect-preferences interactive ---------------- */

#pref-widget { max-width: 860px; }

.pref-traj {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 4px 0 20px;
}

.pref-traj figure.media { margin: 0; }

.pref-traj .traj-tag {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--ink-soft);
  text-align: center;
  margin-top: 8px;
}

/* shared scrubber that drives both trajectory videos at once */
.pref-scrub-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 4px 0 22px;
}

.pref-play {
  flex: none;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: none;
  background: var(--ink-deep);
  color: #fff;
  font-size: 0.85rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s ease;
}
.pref-play:hover { background: var(--sky-deep); }

.pref-scrub {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  border-radius: 999px;
  background: rgba(10, 18, 32, 0.15);
  cursor: pointer;
}
.pref-scrub::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--sky-deep);
  border: 2px solid #fff;
  box-shadow: 0 1px 3px rgba(10, 18, 32, 0.3);
  cursor: pointer;
}
.pref-scrub::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--sky-deep);
  border: 2px solid #fff;
  cursor: pointer;
}

.pref-panel { display: flex; flex-direction: column; gap: 10px; }

.pref-q {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ink-deep);
  text-align: center;
  margin: 2px 0 6px;
}

.pref-axis {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 9px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.pref-axis .axis-name { font-weight: 600; color: var(--ink-soft); font-size: 0.95rem; }
.pref-axis .axis-name small { display: block; font-weight: 400; font-size: 0.78rem; color: rgba(44,62,80,0.6); }

.pref-controls { display: inline-flex; align-items: center; gap: 8px; }

.pref-choice { display: inline-flex; gap: 6px; }

.axis-remove {
  border: none;
  background: transparent;
  color: rgba(var(--muted), 0.4);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  padding: 0 2px;
  transition: color 0.12s ease;
}
.axis-remove:hover { color: var(--m-bc); }

.pref-add {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.pref-add input {
  flex: 1;
  min-width: 0;
  padding: 10px 14px;
  border: 1px dashed var(--sky);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.6);
  font-family: var(--font-body);
  font-size: 0.92rem;
  color: var(--ink);
}
.pref-add input:focus { outline: none; border-style: solid; border-color: var(--sky-deep); }

.pref-add button {
  padding: 10px 18px;
  border: none;
  border-radius: 12px;
  background: var(--sky-deep);
  color: #fff;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.12s ease;
}
.pref-add button:hover { background: var(--ink-deep); }

.pref-choice button {
  width: 38px;
  height: 34px;
  border-radius: 9px;
  border: 2px solid var(--line);
  background: var(--bg-soft);
  color: var(--ink-soft);
  font-family: var(--font-head);
  font-weight: 700;
  cursor: pointer;
  transition: all 0.12s ease;
}

.pref-choice button:hover { border-color: var(--sky); }
.pref-choice button.picked { background: var(--ink-deep); border-color: var(--ink-deep); color: #fff; }

.pref-summary {
  margin-top: 18px;
  text-align: center;
  font-size: 0.95rem;
  min-height: 26px;
}

.pref-summary .badge {
  display: inline-block;
  padding: 7px 16px;
  border-radius: 999px;
  font-weight: 600;
  animation: pop 0.25s ease;
}

.pref-summary .badge.thin { background: rgba(var(--muted), 0.5); color: #fff; }
.pref-summary .badge.rich { background: var(--sky-deep); color: #fff; }

/* ---------------- task band (band of tasks we did) ---------------- */

.task-band {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 30px auto;
}

.task-band figure { margin: 0; }
.task-band .media-frame:not(.loaded) { aspect-ratio: 16 / 9; }
.task-band figcaption {
  margin-top: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--ink-soft);
}
.task-band-note {
  text-align: center;
  font-size: 0.74rem;
  color: rgba(var(--muted), 0.4);
  margin: 12px 0 0;
}

/* per-bowl selector on the cube task video */
.band-bowls {
  display: flex;
  justify-content: center;
  gap: 6px;
  margin-top: 6px;
}
.band-bowl {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 600;
  padding: 4px 9px;
  border-radius: 999px;
  border: 1.5px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.12s ease;
}
.band-bowl .bowl-dot { width: 9px; height: 9px; }
.band-bowl.blue   .bowl-dot { background: #3b82d6; }
.band-bowl.orange .bowl-dot { background: #e8893a; }
.band-bowl.yellow .bowl-dot { background: #e5c84a; }
.band-bowl:hover { border-color: var(--sky); }
.band-bowl.active { background: var(--ink-deep); border-color: var(--ink-deep); color: #fff; }

/* ---------------- grouped bar chart (paper Fig. 3 names + colors) ---------------- */

:root {
  --m-bc:  #ba614c;  /* Behavior Cloning */
  --m-fbc: #a5babc;  /* Filtered BC */
  --m-spp: #8fb364;  /* Single Preferences w/ matching pairs */
  --m-spc: #958aa5;  /* Single Preferences w/ matching comparisons */
  --m-fpl: #f6c94a;  /* FPL (Ours) */
}

.gbar-area {
  position: relative;
  height: 250px;
  margin: 6px 0 0 38px;
  border-bottom: 2px solid var(--ink-soft);
}

.gbar-gridline {
  position: absolute;
  left: 0;
  right: 0;
  border-top: 1px dashed rgba(10, 18, 32, 0.14);
}

.gbar-gridline span {
  position: absolute;
  left: -34px;
  top: -0.7em;
  width: 28px;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--ink-soft);
}

.gbar-groups { position: absolute; inset: 0; display: flex; }

.gbar-group {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 3px;
  height: 100%;
}

.gbar-group.avg { background: rgba(10, 18, 32, 0.045); border-radius: 8px 8px 0 0; }

.gbar-col {
  width: 15%;
  max-width: 20px;
  height: 0;
  border-radius: 3px 3px 0 0;
  border: 0.5px solid rgba(10, 18, 32, 0.25);
  animation: grow-up 0.9s cubic-bezier(0.2, 0.7, 0.3, 1) forwards;
}

.gbar-col.bc  { background: var(--m-bc); }
.gbar-col.fbc { background: var(--m-fbc); }
.gbar-col.spp { background: var(--m-spp); }
.gbar-col.spc { background: var(--m-spc); }
.gbar-col.fpl { background: var(--m-fpl); }

@keyframes grow-up { from { height: 0; } to { height: var(--h); } }

.gbar-names { display: flex; margin: 6px 0 0 38px; }
.gbar-names span {
  flex: 1;
  text-align: center;
  font-size: 0.74rem;
  font-weight: 600;
  color: var(--ink-soft);
  padding: 0 2px;
}
.gbar-names span.avg { font-weight: 700; color: var(--ink-deep); }

.gbar-legend {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 18px;
  margin: 22px 0 2px;
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.gbar-legend span { display: inline-flex; align-items: center; gap: 7px; }
.gbar-legend i {
  width: 13px;
  height: 13px;
  border-radius: 3px;
  border: 0.5px solid rgba(10, 18, 32, 0.25);
  display: inline-block;
}
.gbar-legend .l-fpl { font-weight: 700; color: var(--ink-deep); }

/* ---------------- reward-signal interactive ---------------- */

#reward-widget { max-width: 980px; }

#reward-widget .reward-video { max-width: 760px; margin-left: auto; margin-right: auto; }
.reward-video .media-frame:not(.loaded) { aspect-ratio: 1280 / 360; }

#reward-widget .reward-scrub-row { max-width: 760px; margin: 4px auto 24px; }

.reward-charts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.reward-panel {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 12px 4px;
}

.reward-title {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 0.85rem;
  text-align: center;
  margin: 2px 0 4px;
  color: var(--ink-deep);
}

.reward-svg { display: block; width: 100%; height: auto; }

.rline { transition: opacity 0.18s ease, stroke-width 0.18s ease; }

/* time playhead: a clear solid vertical bar that tracks the video position */
#reward-ph-fpl, #reward-ph-bin {
  stroke: #1a1a2e;
  stroke-width: 2;
  stroke-dasharray: none;
}

.reward-legend-hint { font-weight: 400; opacity: 0.6; }

.rlegend {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--ink-soft);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 11px;
  cursor: pointer;
  transition: all 0.12s ease;
}
.rlegend:hover { border-color: var(--sky); }
.rlegend.active { background: var(--ink-deep); border-color: var(--ink-deep); color: #fff; }
.reward-legend-overall { display: inline-flex; align-items: center; }

.reward-legend { margin-top: 18px; }

.reward-legend-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 7px 14px;
  font-size: 0.8rem;
  color: var(--ink-soft);
}
.reward-legend-row span { display: inline-flex; align-items: center; }
.reward-legend-row i {
  width: 13px;
  height: 13px;
  border-radius: 3px;
  display: inline-block;
  margin-right: 5px;
}
.reward-legend-group { font-weight: 600; }
.reward-legend-sep { opacity: 0.35; }

.reward-note {
  max-width: 780px;
  margin: 14px auto 0;
  text-align: center;
  font-size: 0.9rem;
  font-style: italic;
  line-height: 1.55;
  color: var(--ink-soft);
}

@media (max-width: 760px) {
  .reward-charts { grid-template-columns: 1fr; }
}

/* ---------------- bibtex ---------------- */

.bibtex-card {
  position: relative;
  background: var(--ink-deep);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.bibtex-card pre { margin: 0; overflow-x: auto; }

.bibtex-card code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: #e8eef5;
}

.copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid rgba(232, 238, 245, 0.3);
  background: transparent;
  color: #e8eef5;
  cursor: pointer;
}

.copy-btn:hover { background: var(--sky-deep); border-color: var(--sky-deep); }

/* ---------------- responsive ---------------- */

@media (max-width: 760px) {
  .hero { padding-top: 56px; }
  .compare-grid { grid-template-columns: 1fr; }
  .vs-badge { justify-self: center; }
  .bar-row { grid-template-columns: 120px 1fr 40px; font-size: 0.78rem; }
  .task-band { grid-template-columns: repeat(2, 1fr); }
  .gbar-names span { font-size: 0.62rem; }
  .gbar-col { border-radius: 2px 2px 0 0; }
}

/* ---------------- theme toggle ---------------- */

.theme-toggle {
  position: fixed;
  top: 14px;
  right: 14px;
  z-index: 200;
  display: none; /* occluded — blue palette is the default; set to flex to re-enable */
  gap: 6px;
  padding: 5px;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.theme-toggle button {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  padding: 0;
  cursor: pointer;
  border: 2px solid transparent;
  transition: transform 0.12s ease, border-color 0.12s ease;
}
.theme-toggle button:hover { transform: scale(1.1); }
.theme-toggle button[data-set-theme="warm"] { background: linear-gradient(135deg, #f3eee3 45%, #bb7a4f 55%); }
.theme-toggle button[data-set-theme="blue"] { background: linear-gradient(135deg, #d7efff 45%, #5dade2 55%); }
.theme-toggle button.active { border-color: var(--ink-deep); }

@media (max-width: 760px) {
  .theme-toggle { top: 10px; right: 10px; }
}