/* ---------- Theme tokens ---------- */
:root {
  --bg: #ffffff;
  --bg-alt: #ffffff;
  --surface: #ffffff;
  --text: #111111;
  --text-soft: #4a4a4a;
  --text-mute: #8a8a8a;
  --border: #ececec;
  --border-strong: #d8d8d8;
  --accent: #111111;
  --link: #2a5db0;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --maxw: 1225px;
  --maxw-narrow: 862px;
}

/* ---------- Base ---------- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 64px; }
body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "ss01", "cv11";
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 32px;
}
.container.narrow { max-width: var(--maxw-narrow); }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid transparent;
}
.nav.scrolled { border-bottom-color: var(--border); }

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-logo {
  font-weight: 600;
  letter-spacing: 0.02em;
  color: rgba(242, 113, 0, 1);
  font-size: 15px;
}
.nav-logo:hover { text-decoration: none; }

.nav-links {
  display: flex;
  gap: 24px;
  flex: 1;
  justify-content: flex-end;
  flex-wrap: wrap;
}
.nav-links a {
  color: var(--text-soft);
  font-weight: 400;
  font-size: 14px;
}
.nav-links a:hover {
  color: var(--text);
  text-decoration: none;
}

/* ---------- Hero ---------- */
.hero {
  padding: 32px 0 0;
  text-align: center;
}
#rollouts { padding-top: 16px; }

.hero-meta { margin-bottom: 18px; }
.badge {
  display: inline-block;
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--text-mute);
}
.title {
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.2;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin: 0 auto 28px;
  max-width: 1160px;
  color: var(--text);
}
.title-row { display: block; }
.title-line { display: block; font-weight: 400; color: var(--text-mute); font-size: 0.6em; letter-spacing: 0.04em; text-transform: uppercase; margin-bottom: 8px; }
.title-accent { display: block; }
.title-brand { color: rgba(242, 113, 0, 1); }

.authors {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: baseline;
  gap: 4px 18px;
  margin: 0 0 6px;
  font-size: 17.5px;
  color: var(--text);
}
.author { white-space: nowrap; }
.author sup {
  color: var(--text-mute);
  font-weight: 400;
  font-size: 0.7em;
  line-height: 0;
  position: relative;
  top: -0.45em;
  vertical-align: baseline;
}

.affiliations {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 16px;
  font-size: 15.5px;
  color: var(--text-mute);
  margin-bottom: 6px;
}
.affiliations sup { margin-right: 2px; }

.equal-contrib {
  text-align: center;
  font-size: 13px;
  color: var(--text-mute);
  margin-bottom: 16px;
}
.equal-contrib sup { margin-right: 2px; }

.links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 0;
}
.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  font-weight: 600;
  font-size: 13.5px;
  letter-spacing: 0.01em;
  border: 1px solid var(--accent);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.link-btn:hover {
  text-decoration: none;
  background: #2a2a2a;
  border-color: #2a2a2a;
}
.link-btn svg { width: 14px; height: 14px; }

.teaser-wrap {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: #000;
}
.teaser-video {
  width: 100%;
  display: block;
  aspect-ratio: 15 / 9;
  object-fit: cover;
  object-position: left;
  background: #000;
}
.hero-abstract {
  max-width: var(--maxw-narrow);
  margin: 32px auto 0;
  text-align: left;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-soft);
}
.hero-abstract em {
  color: var(--text-mute);
  font-style: normal;
}

.method-figure {
  margin: 0;
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: 24px;
}
.method-figure img {
  width: 100%;
  height: auto;
  display: block;
}
.method-text {
  margin: 24px 0 0;
}
.method-text p {
  margin: 0;
  font-size: 19.2px;
}
.method-points {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 13px;
}
.method-points li {
  position: relative;
  padding-left: 21px;
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-soft);
}
.method-points li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.62em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(242, 113, 0, 1);
}
.method-points strong {
  color: var(--text);
  font-weight: 600;
}

/* ---------- Sections ---------- */
.section { padding: 40px 0; }
.section-alt { background: var(--bg-alt); }

.section-head { text-align: center; margin-bottom: 25.6px; }
.section-title {
  font-size: clamp(22px, 2.6vw, 28px);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
  color: var(--text);
  text-align: center;
}
.section-sub {
  margin: 0;
  color: var(--text-mute);
  font-size: 15px;
}

.lead {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-soft);
}
.lead em { color: var(--text-mute); font-style: normal; }

/* ---------- Task tabs (rollouts) ---------- */
.task-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  justify-content: flex-start;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--border);
}
.task-tab {
  padding: 10px 16px;
  border: none;
  background: transparent;
  color: var(--text-mute);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  font-size: 14px;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
}
.task-tab:hover {
  color: var(--text);
}
.task-tab.active {
  color: var(--text);
  border-bottom-color: var(--text);
}

.task-stage {
  position: relative;
  background: #000;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.task-video {
  width: 100%;
  display: block;
  aspect-ratio: 15 / 9;
  object-fit: cover;
  object-position: left;
  background: #000;
}
.task-info {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  padding: 18px 20px;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.55);
  pointer-events: none;
}
.task-info h3 {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}
.task-info p {
  margin: 0;
  color: rgba(255, 255, 255, 0.85);
  font-size: 14px;
}

/* ---------- Grid (robustness, training) ---------- */
.grid {
  display: grid;
  gap: 16px;
}
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Policy rollout videos: 3 per row, 2 rows */
#rollouts .grid { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 900px) {
  #rollouts .grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px) {
  #rollouts .grid { grid-template-columns: 1fr; }
}

.card {
  position: relative;
  margin: 0;
  background: #000;
  border-radius: var(--radius-md);
  overflow: hidden;
}
.card video {
  width: 100%;
  display: block;
  aspect-ratio: 15 / 9;
  object-fit: cover;
  object-position: left;
  background: #000;
}
#rollouts .card video { filter: brightness(1.1); }
#robustness .card video { filter: brightness(1.2); }          /* match light task */
#robustness .card video.dim-none { filter: brightness(1); }   /* Object variation */
#robustness .card video.dim-bg { filter: brightness(1.1); }   /* Background distractions */
#rollouts .card video.dim { filter: brightness(0.70); }       /* Pool Shot */
#rollouts .card video.dim-egg { filter: brightness(1.1); }    /* Egg Flip */
#rollouts .card video.dim-flower { filter: brightness(0.70); } /* Flower */
#rollouts .card video.dim-cube { filter: brightness(1.1); }   /* Cube Pick */
/* Display-only videos: not interactive (no hover/pause/seek) */
#rollouts .card video,
#robustness .card video {
  pointer-events: none;
}
.card figcaption { display: none; }

/* Video bottom caption (built in script.js), styled like the evaluation overlay */
.vid-tag-br {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
  padding: 12px 14px;
  color: #fff;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.55);
  pointer-events: none;
}
.vid-tag-name {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.01em;
}
.vid-tag-sub {
  font-size: 12px;
  font-weight: 500;
  opacity: 0.82;
}

/* Speed toggle button (Sampling & Edit visualization videos) */
.speed-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 3;
  min-width: 44px;
  padding: 5px 11px;
  background: rgba(0, 0, 0, 0.55);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  font-size: 11.5px;
  font-weight: 600;
  font-family: inherit;
  letter-spacing: 0.02em;
  cursor: pointer;
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.speed-btn:hover {
  background: rgba(0, 0, 0, 0.82);
  border-color: rgba(255, 255, 255, 0.6);
}

/* ---------- Horizontal scroll row ---------- */
.scroll-row-wrap {
  position: relative;
}
.scroll-row {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  padding: 4px 0 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}
.scroll-row::-webkit-scrollbar { height: 6px; }
.scroll-row::-webkit-scrollbar-track { background: transparent; }
.scroll-row::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: 3px;
}
.scroll-row .card {
  flex: 0 0 auto;
  /* match a Rollouts 3-up grid cell: (container content - 2 gaps) / 3 */
  width: calc((min(100vw, var(--maxw)) - 96px) / 3);
  scroll-snap-align: start;
}

/* Visualization sections (Q / Sampling / Edit): video grids */
.vis-grid {
  display: grid;
  gap: 16px;
  align-items: start;
}
.vis-grid-3 { grid-template-columns: repeat(3, 1fr); }
.vis-grid-2 { grid-template-columns: repeat(2, 1fr); }
.vis-grid-1 { grid-template-columns: 1fr; }
/* Sampling & Edit panoramic strips: 1280x360 == exactly 32:9, so a 32/9 box
   shows the full frame uncropped. */
.vis-grid .card.wide video {
  width: 100%;
  aspect-ratio: 32 / 9;
  object-fit: cover;
  object-position: center;
}
@media (max-width: 900px) {
  .vis-grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px) {
  .vis-grid-3 { grid-template-columns: 1fr; }
}

.scroll-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 5;
}
.scroll-btn:hover {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}
.scroll-btn:disabled {
  opacity: 0;
  pointer-events: none;
}
.scroll-btn svg { width: 16px; height: 16px; }
.scroll-btn-left { left: -18px; }
.scroll-btn-right { right: -18px; }

.scroll-hint {
  display: inline-block;
  margin-left: 8px;
  font-size: 12px;
  color: var(--text-mute);
  letter-spacing: 0.04em;
}

/* ---------- Evaluation ---------- */
.eval-layout {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 24px;
  align-items: start;
}
.eval-results {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  /* height is set in script.js to match the video */
}
.eval-results-head {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-mute);
  margin-bottom: 14px;
}
#eval-bars {
  flex: 1;
  display: flex;
  gap: 22px;
  min-height: 0;
}
.bar-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}
.bar-group + .bar-group {
  border-left: 1px solid var(--border);
  padding-left: 22px;
}
.bar-cols {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 10.49px;
  min-height: 0;
  padding-top: 22px; /* room for value labels above full-height bars */
}
.bar-col {
  flex: 0 0 auto;
  width: clamp(40px, 5.5vw, 58px);
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100%;
}
.bar-plot {
  flex: 1;
  width: 100%;
  min-height: 0;
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: center;
}
.bar-fill {
  width: clamp(22px, 80%, 48px);
  height: var(--h);
  background: var(--border-strong);
  border-radius: 6px 6px 0 0;
  transition: height 0.4s ease;
}
.bar-val {
  position: absolute;
  left: 50%;
  bottom: var(--h);
  transform: translateX(-50%);
  margin-bottom: 4px;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--text-soft);
  white-space: nowrap;
}
.bar-label {
  margin-top: 8px;
  font-size: 11px;
  line-height: 1.25;
  color: var(--text-soft);
  text-align: center;
  white-space: nowrap;
}
.bar-col.is-ours .bar-fill {
  background: rgba(242, 113, 0, 1);
}
.bar-col.is-ours .bar-label,
.bar-col.is-ours .bar-val {
  color: var(--text);
  font-weight: 600;
}
.bar-group-title {
  margin-top: 10px;
  text-align: center;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text);
}
.eval-note {
  margin: 14px 0 0;
  font-size: 12px;
  color: var(--text-mute);
}
@media (max-width: 900px) {
  .eval-layout { grid-template-columns: 1fr; }
}

/* ---------- BibTeX ---------- */
.code-wrap {
  position: relative;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 4px 10px;
  background: var(--bg);
  color: var(--text-soft);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  font-size: 11px;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
}
.copy-btn:hover { background: var(--text); color: #fff; border-color: var(--text); }
.code {
  margin: 0;
  padding: 18px 20px;
  font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-soft);
  overflow-x: auto;
}

/* ---------- Footer ---------- */
.footer {
  padding: 28px 0;
  text-align: center;
  color: var(--text-mute);
  font-size: 13px;
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .nav-links { gap: 14px; }
  .nav-links a { font-size: 13px; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .eval-grid { grid-template-columns: 1fr; }
  .hero { padding: 48px 0 36px; }
  .section { padding: 48px 0; }
  .scroll-btn-left { left: 4px; }
  .scroll-btn-right { right: 4px; }
}
@media (max-width: 540px) {
  .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr; }
  .container { padding: 0 18px; }
  .nav-inner { padding: 14px 18px; }
  .nav-links { display: none; }
}