/* ============================================================
   Video Regenerate — project page
   Palette & layout follow Descript's brand academic template
   (Red & Maroon ramps), matching descriptinc.github.io/uvm-v2
   ============================================================ */

:root {
  /* Descript brand palette — Red & Maroon ramps */
  --rec-red:     #F73B3B; /* CTA */
  --rec-red-dk:  #B81B1E; /* CTA hover / edit */
  --red-50:      #FFE8DB;
  --light-peach: #FFD6C5;
  --peach:       #FF8969;
  --canvas:      #FFF8F4; /* warm section background */
  --edit-maroon: #651A39; /* primary accent */
  --maroon-900:  #390A1A;
  --neutral-50:  #F1EAED;
  --neutral-100: #E4DDE0;
  --neutral-200: #D1C7CB;
  --neutral-600: #715661;
  --screen-black:#110A0D;

  /* Semantic tokens */
  --bg:          #ffffff;
  --bg-sunken:   var(--neutral-50);
  --ink:         var(--screen-black);
  --ink-soft:    var(--neutral-600);
  --ink-faint:   #9c8890;
  --line:        var(--neutral-100);
  --accent:      var(--edit-maroon);
  --accent-2:    var(--rec-red);
  --accent-soft: var(--light-peach);
  --edit:        var(--rec-red-dk);
  --edit-soft:   rgba(255, 137, 105, 0.30);

  --maxw: 1100px;
  --maxw-narrow: 760px;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(57, 10, 26, .05), 0 10px 30px rgba(57, 10, 26, .07);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, Menlo, Monaco, Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 18px/1.6 var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; }
em { color: var(--accent); font-style: italic; }
strong { font-weight: 600; }

.grain { display: none; }

/* ---------- HERO ---------- */
.hero {
  background: var(--canvas);
  text-align: center;
  padding: clamp(56px, 9vw, 96px) clamp(18px, 4vw, 24px) 56px;
  border-bottom: 1px solid var(--line);
}
.hero__inner { max-width: var(--maxw); margin: 0 auto; }
.eyebrow {
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--rec-red); font-weight: 500; margin: 0 0 14px;
}
.backlink { color: var(--rec-red); text-decoration: none; }
.backlink:hover { color: var(--rec-red-dk); text-decoration: underline; }
.hero__title {
  font-size: clamp(44px, 8vw, 76px); line-height: 1.04; font-weight: 600;
  letter-spacing: -0.02em; color: var(--ink); margin: 0 0 16px;
}
.hero__tagline {
  font-size: clamp(19px, 3vw, 23px); color: var(--ink-soft);
  margin: 0 auto 22px; max-width: 720px; font-weight: 400;
}
.hero__tagline em { color: var(--edit-maroon); }
.authors { font-size: 19px; color: var(--ink-soft); margin: 0 0 6px; line-height: 1.5; }
.authors span { display: inline-block; margin: 0 8px; }
.affiliations { font-size: 16px; color: var(--edit-maroon); font-weight: 600; margin: 0 0 30px; }

.hero__cta { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin-bottom: 52px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: 999px; font-size: 16px; font-weight: 600;
  letter-spacing: 0.01em; cursor: pointer; border: 1px solid transparent;
  transition: background-color 0.15s, color 0.15s, border-color 0.15s;
}
.btn--primary { background: var(--rec-red); color: #fff; }
.btn--primary:hover { background: var(--rec-red-dk); text-decoration: none; }
.btn--ghost { background: transparent; color: var(--edit-maroon); border-color: var(--neutral-200); }
.btn--ghost:hover { background: var(--canvas); border-color: var(--edit-maroon); text-decoration: none; }
.btn--sm { padding: 8px 15px; font-size: 14px; }

/* ---------- Paper / companion-work callout ---------- */
.paper-callout {
  background: var(--canvas); border: 1px solid var(--neutral-200);
  border-left: 4px solid var(--rec-red); border-radius: var(--radius); padding: 22px 24px;
  margin-top: 22px;
}
.paper-callout__tag {
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--rec-red); margin: 0 0 10px;
}
.paper-callout__title {
  font-size: 18px; font-weight: 600; line-height: 1.35;
  color: var(--ink); margin: 0 0 8px; letter-spacing: -0.01em;
}
.paper-callout__authors, .paper-callout__body { color: var(--ink-soft); font-size: 14px; margin: 0 0 16px; }
.paper-callout__body strong { color: var(--edit-maroon); }
.paper-callout__links { display: flex; gap: 8px; flex-wrap: wrap; }

.hero__sub {
  max-width: 880px; margin-left: auto; margin-right: auto; color: var(--ink-soft); font-size: 17px; text-align: left;
}

/* ---------- SPOTLIGHT (hero demos) ---------- */
.hero-duo {
  max-width: 820px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr; gap: 36px;
}
.spotlight { max-width: none; margin: 0; }
.spotlight__kicker {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--rec-red); margin: 0 0 10px; text-align: left;
}
.spotlight__frame {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px; box-shadow: var(--shadow);
}
.spotlight__caption {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  margin-top: 16px; color: var(--ink-soft); font-size: 15px;
}
.spotlight__caption span { font-weight: 600; font-size: 17px; color: var(--ink); }
.spotlight__hint {
  font-family: var(--font-mono); font-size: 12px !important; font-weight: 500 !important;
  color: var(--ink-faint) !important; text-transform: uppercase; letter-spacing: 0.04em;
}

/* ---------- VIDEO TILE ---------- */
.video-tile {
  position: relative; border-radius: var(--radius-sm); overflow: hidden;
  aspect-ratio: 16 / 9; background: #1b1418;
  border: 1px solid var(--line);
}
.video-tile__video {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; display: none;
}
.video-tile.has-video .video-tile__video { display: block; }
.video-tile.has-video .video-tile__placeholder { display: none; }

.video-tile__placeholder {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 14px;
  background:
    repeating-linear-gradient(115deg, rgba(101,26,57,0.04) 0 2px, transparent 2px 10px),
    radial-gradient(120% 90% at 50% 28%, #fff 0%, var(--canvas) 55%, #f3e7e0 100%);
  color: var(--ink-faint); font-size: 13px; letter-spacing: 0.03em;
}
.ph-face { position: relative; width: 92px; height: 92px; }
.ph-face__head {
  position: absolute; inset: 0; margin: auto; width: 70px; height: 84px;
  border-radius: 50% 50% 46% 46%;
  background: linear-gradient(160deg, var(--edit-maroon), var(--maroon-900));
  box-shadow: inset 0 -8px 22px rgba(57,10,26,0.4);
}
.ph-face__mouth {
  position: absolute; left: 50%; top: 64%; transform: translateX(-50%);
  width: 26px; height: 8px; border-radius: 8px;
  background: var(--rec-red);
  box-shadow: 0 0 14px rgba(247,59,59,0.6);
  animation: talk 1.1s ease-in-out infinite;
}
.ph-face--jc .ph-face__head { animation: jcjump 1.6s steps(2) infinite; }
@keyframes talk {
  0%,100% { height: 5px; opacity: 0.8; }
  50% { height: 13px; opacity: 1; }
}
@keyframes jcjump {
  0%, 49% { transform: translate(0,0) rotate(0); }
  50%,100% { transform: translate(7px,-4px) rotate(3deg); }
}

.video-tile__play {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%,-50%);
  width: 58px; height: 58px; border-radius: 50%; border: none; cursor: pointer;
  background: var(--rec-red); color: #fff;
  display: grid; place-items: center; z-index: 4; opacity: 0;
  box-shadow: 0 6px 18px rgba(247,59,59,0.4);
  transition: transform 0.15s, background 0.2s, opacity 0.2s;
}
.video-tile:hover .video-tile__play,
.video-tile.has-video .video-tile__play { opacity: 1; }
.video-tile__play:hover { transform: translate(-50%,-50%) scale(1.08); background: var(--rec-red-dk); }
.video-tile.is-playing .video-tile__play { opacity: 0; }

/* mute / unmute toggle */
.video-tile__mute {
  position: absolute; top: 12px; right: 12px; z-index: 7;
  width: 34px; height: 34px; border-radius: 50%; border: none; cursor: pointer;
  background: rgba(17, 10, 13, 0.55); color: #fff; display: none; place-items: center;
  -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
  transition: background 0.2s, opacity 0.2s;
}
.video-tile.has-video .video-tile__mute { display: grid; }
.video-tile__mute:hover { background: rgba(17, 10, 13, 0.82); }
.video-tile__mute svg { width: 18px; height: 18px; }
.video-tile__mute.is-muted { color: var(--light-peach); }

/* fullscreen toggle (sits left of the mute button) */
.video-tile__fs {
  position: absolute; top: 12px; right: 54px; z-index: 7;
  width: 34px; height: 34px; border-radius: 50%; border: none; cursor: pointer;
  background: rgba(17, 10, 13, 0.55); color: #fff; display: none; place-items: center;
  -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
  transition: background 0.2s, opacity 0.2s;
}
.video-tile.has-video .video-tile__fs { display: grid; }
.video-tile__fs:hover { background: rgba(17, 10, 13, 0.82); }
.video-tile__fs svg { width: 18px; height: 18px; }
/* in fullscreen, let the video fill the screen and center it */
.video-tile:fullscreen { display: flex; align-items: center; justify-content: center; background: #000; }
.video-tile:fullscreen .video-tile__video { width: 100%; height: 100%; object-fit: contain; }
.video-tile:-webkit-full-screen { background: #000; }
.video-tile:-webkit-full-screen .video-tile__video { width: 100%; height: 100%; object-fit: contain; }

/* scrubber */
.scrubber {
  position: absolute; left: 12px; right: 12px; bottom: 12px; z-index: 5;
  opacity: 0; transition: opacity 0.2s;
}
.video-tile:hover .scrubber,
.video-tile.is-playing .scrubber,
.is-revealed .scrubber { opacity: 1; }
.scrubber__track {
  position: relative; height: 8px; border-radius: 6px; cursor: pointer;
  background: rgba(255,255,255,0.32); overflow: hidden;
}
/* playhead — a thin marker, so the regenerated-frame bands stay visible */
.scrubber__progress {
  position: absolute; left: 0; top: -1px; bottom: -1px; width: 2px;
  margin-left: -1px; background: #fff; border-radius: 2px;
  box-shadow: 0 0 4px rgba(0,0,0,0.5);
}
.scrubber__regions { position: absolute; inset: 0; }
/* regenerated frame spans on the timeline (temporal, not spatial) */
.scrubber__region {
  position: absolute; top: 0; bottom: 0;
  background: var(--rec-red); opacity: 0; transition: opacity 0.3s;
}
.scrubber__region--bridge { background: var(--rec-red); }
.is-revealed .scrubber__region { opacity: 0.95; }

/* region badge */
.region-badge {
  position: absolute; top: 12px; left: 12px; z-index: 6;
  font-family: var(--font-mono);
  font-size: 11px; font-weight: 500; letter-spacing: 0.04em;
  padding: 5px 11px; border-radius: 999px;
  background: var(--rec-red); color: #fff;
  opacity: 0; transform: translateY(-6px); transition: opacity 0.3s, transform 0.3s;
}
.is-revealed .region-badge { opacity: 1; transform: translateY(0); }

/* frame-level indicator — a ring that lights up only while the playhead
   is inside a regenerated span (i.e. on the regenerated frames) */
.video-tile::after {
  content: ""; position: absolute; inset: 0; z-index: 5; pointer-events: none;
  border: 3px solid var(--rec-red); border-radius: inherit;
  opacity: 0; transition: opacity 0.12s;
}
.is-revealed .video-tile.in-edit::after,
.video-tile--jc.in-edit::after { opacity: 1; }
.is-revealed .video-tile.in-edit .region-badge,
.video-tile--jc.in-edit .region-badge { box-shadow: 0 0 0 4px color-mix(in srgb, var(--rec-red) 30%, transparent); }

/* jumpcut tiles: boundary marker + label always visible */
.video-tile--jc .scrubber { opacity: 1; }
.video-tile--jc .scrubber__region { opacity: 0.95; }
.video-tile--jc .region-badge { opacity: 1; transform: none; }

/* ---------- Transcript (tracked changes) ---------- */
.transcript { font-size: 18px; line-height: 1.75; color: var(--ink); }
.transcript--center { text-align: left; margin-left: auto; margin-right: auto; }
.transcript__row { margin: 0; }
.transcript__row + .transcript__row { margin-top: 8px; }
/* the ground-truth (original) line only appears once the edit is revealed */
.transcript__row--original { display: none; color: var(--ink-soft); }
.is-revealed .transcript__row--original,
.transcript--on .transcript__row--original { display: block; }
.transcript__label {
  font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 0.07em;
  text-transform: uppercase; color: var(--ink-faint); margin-right: 9px;
  display: none; vertical-align: 1px;
}
.is-revealed .transcript__label,
.transcript--on .transcript__label { display: inline-block; }
.transcript .seg {
  transition: background 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
  border-radius: 4px;
}
/* new / regenerated words — highlighted on reveal */
.is-revealed .transcript .seg.ins,
.transcript--on .transcript .seg.ins {
  background: var(--light-peach); color: var(--rec-red-dk); padding: 0 3px;
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--rec-red) 30%, transparent);
}
/* unified diff: removed words struck through, hidden until the edit is revealed */
.transcript .seg.del {
  text-decoration: line-through; text-decoration-color: var(--peach);
  text-decoration-thickness: 2px; color: var(--ink-faint);
}
.transcript__row--diff .seg.del,
.transcript__row--diff .seg--gap { display: none; }
.is-revealed .transcript__row--diff .seg.del,
.transcript--on .transcript__row--diff .seg.del,
.is-revealed .transcript__row--diff .seg--gap,
.transcript--on .transcript__row--diff .seg--gap { display: inline; }

/* ---------- SECTIONS ---------- */
.section {
  max-width: var(--maxw); margin: 0 auto;
  padding: clamp(52px, 8vw, 72px) clamp(18px, 4vw, 32px);
  border-bottom: 1px solid var(--line);
}
.section__head { margin-bottom: 24px; }
.section h2 {
  font-size: clamp(26px, 4vw, 32px); font-weight: 600; letter-spacing: -0.01em;
  color: var(--ink); margin: 0; padding-bottom: 8px;
  border-bottom: 2px solid var(--accent); display: inline-block;
}
.prose { max-width: var(--maxw-narrow); }
.prose p { margin: 0 0 18px; color: var(--ink-soft); }
.prose strong { color: var(--ink); }
.prose--lead { font-size: clamp(19px, 2.4vw, 22px); color: var(--ink); margin-bottom: 32px; }
.prose--lead strong { color: var(--edit-maroon); }

/* ---------- METHOD subheads + two-col text/figure ---------- */
.method-h3, .subhead { font-size: 22px; font-weight: 600; color: var(--ink); margin: 44px 0 16px; letter-spacing: -0.01em; }
/* stacked + full width: text and figures span the section, figures responsive */
.cols { display: block; }
.col-text { max-width: none; }
.col-text p { color: var(--ink-soft); margin: 0 0 16px; }
.col-text strong { color: var(--ink); }
.col-fig { margin: 22px 0 0; width: 100%; }
.denoise.col-fig, .stmap.col-fig { max-width: none; width: 100%; }
.stmap svg, .pipeline__svg { width: 100%; height: auto; display: block; }

/* ---------- PIPELINE (flex) ---------- */
.pipeline {
  margin: 8px 0 8px; padding: 26px 18px; display: flex; align-items: flex-end;
  justify-content: space-between; gap: 6px; flex-wrap: wrap;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow);
}
.pipeline__stage { flex: 1 1 0; min-width: 120px; display: flex; flex-direction: column; align-items: center; gap: 12px; padding: 10px 6px; }
.pipeline__icon { width: 100%; max-width: 120px; height: 56px; color: var(--edit-maroon); display: grid; place-items: center; }
.pipeline__cap { font-size: 13px; line-height: 1.3; color: var(--ink-soft); font-weight: 500; text-align: center; min-height: 2.6em; }
.pipeline__arrow { align-self: flex-end; margin-bottom: 44px; color: var(--neutral-200); font-size: 22px; }
.pipeline__stage--model { gap: 6px; }
.pipeline__model {
  width: 100%; max-width: 120px; min-height: 56px; border-radius: 12px;
  background: var(--edit-maroon); color: #fff; display: grid; place-items: center;
  font-weight: 700; font-size: 15px; letter-spacing: .02em;
}
.pipeline__sideins { display: flex; flex-direction: column; gap: 6px; align-items: center; }
.pipeline__textin {
  display: flex; flex-direction: column; align-items: center; gap: 1px;
  background: var(--canvas); border: 1px dashed var(--peach); border-radius: 8px;
  padding: 6px 11px; max-width: 150px;
}
.pipeline__textin-tag { font-family: var(--font-mono); font-size: 10px; letter-spacing: .06em; text-transform: uppercase; color: var(--rec-red); }
.pipeline__textin-words { font-size: 12.5px; color: var(--ink-soft); white-space: nowrap; line-height: 1; }
.pipeline__textin-words svg { display: block; color: var(--edit-maroon); }
.pipeline__down { color: var(--peach); font-size: 16px; line-height: 1; margin-bottom: 2px; }
/* video-out smile: same shape as video-in, but red = regenerated */
.pl-edit path { fill: none; stroke: var(--rec-red); stroke-width: 1.4; stroke-linecap: round; animation: pulseMask 1.8s ease-in-out infinite; }
.pl-edit path:nth-child(2) { animation-delay: .15s; }
.pl-edit path:nth-child(3) { animation-delay: .3s; }
.pl-edit path:nth-child(4) { animation-delay: .45s; }
.pipeline__grid { display: flex; align-items: stretch; justify-content: center; gap: 5px; width: 100%; max-width: 120px; height: 48px; }
.pframe {
  display: block; flex: 1 1 0; position: relative; border-radius: 4px;
  border: 1.5px solid color-mix(in srgb, var(--edit-maroon) 55%, transparent);
  background: color-mix(in srgb, var(--edit-maroon) 10%, transparent);
}
.pframe__low {
  position: absolute; left: 2px; right: 2px; bottom: 2px; height: 38%;
  border-radius: 2px; background: color-mix(in srgb, var(--edit-maroon) 35%, transparent); transition: background .3s;
}
.pframe__low.is-mask { background: var(--rec-red); animation: pulseMask 1.6s ease-in-out infinite; }
.pframe__low.is-filled { background: var(--rec-red-dk); animation: none; }
@keyframes pulseMask { 0%,100%{opacity:.5} 50%{opacity:1} }

/* jumpcut diagram: whole intermediate frames masked then generated */
.jc-pipeline .pipeline__stage--frames { flex: 1.5 1 0; }
.jc-strip { display: flex; gap: 4px; align-items: stretch; justify-content: center; height: 54px; width: 100%; }
.jcf {
  flex: 0 0 auto; width: 20px; border-radius: 4px; position: relative;
  border: 1.5px solid color-mix(in srgb, var(--edit-maroon) 45%, transparent);
  background: color-mix(in srgb, var(--edit-maroon) 8%, transparent);
}
.jcf::before { content: ""; position: absolute; left: 50%; top: 28%; transform: translateX(-50%); width: 6px; height: 6px; border-radius: 50%; background: color-mix(in srgb, var(--edit-maroon) 45%, transparent); }
.jcf::after { content: ""; position: absolute; left: 50%; bottom: 22%; transform: translateX(-50%); width: 9px; height: 3px; border-radius: 3px; background: color-mix(in srgb, var(--edit-maroon) 45%, transparent); }
.jcf--mask { border-color: var(--rec-red); background: var(--rec-red); animation: pulseMask 1.6s ease-in-out infinite; }
.jcf--gen { border-color: var(--rec-red-dk); background: var(--rec-red-dk); }
.jcf--mask::before, .jcf--mask::after, .jcf--gen::before, .jcf--gen::after { display: none; }
@media (max-width: 820px) {
  .pipeline { flex-direction: column; align-items: center; }
  .pipeline__arrow { transform: rotate(90deg); align-self: center; margin-bottom: 0; }
  .pipeline__stage { min-width: 0; }
  .pipeline__cap { min-height: 0; }
}

/* ---------- Denoise matrix ---------- */
.denoise {
  margin: 0; background: var(--bg-sunken); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; display: flex; flex-direction: column;
}
.denoise__row { display: grid; gap: 3px; margin-bottom: 16px; grid-auto-rows: 1fr; min-height: 120px; }
.denoise__cell { border-radius: 2px; opacity: .2; background: var(--edit-maroon); will-change: opacity; }
.denoise__cell.is-mask { background: var(--rec-red); }
.denoise__controls { display: flex; align-items: center; gap: 14px; margin-bottom: 12px; }
.denoise__step { font-family: var(--font-mono); font-size: 13px; color: var(--ink-faint); }
.denoise__cap { font-size: 13.5px; color: var(--ink-soft); margin: 0; }

/* ---------- Space-time map ---------- */
.stmap {
  margin: 0; background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 12px;
}
.stmap__axis { stroke: var(--neutral-200); stroke-width: 1.5; }
.stmap__axlabel { font-family: var(--font-mono); font-size: 11px; fill: var(--ink-faint); }
.stmap__tag { font-family: var(--font-mono); font-size: 10.5px; fill: var(--ink-faint); }
.stmap__tag--onred { fill: #fff; }
.stmap__refs rect { fill: color-mix(in srgb, var(--edit-maroon) 16%, transparent); stroke: var(--edit-maroon); stroke-width: 1; stroke-dasharray: 4 3; }
.stmap__frames rect { fill: none; stroke: var(--neutral-200); stroke-width: 1.2; }
.stmap__gen rect { fill: color-mix(in srgb, var(--peach) 45%, transparent); }
.stmap__audio rect { fill: var(--rec-red); }

/* ---------- disabled button ---------- */
.btn--disabled { cursor: default; opacity: .6; }
.btn--disabled:hover { background: transparent; border-color: var(--neutral-200); color: var(--edit-maroon); }

.reveal-btn {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font); font-size: 13.5px; font-weight: 600; cursor: pointer;
  padding: 8px 15px; border-radius: 999px;
  background: #fff; color: var(--edit-maroon); border: 1px solid var(--neutral-200);
  transition: border-color 0.18s, color 0.18s, background 0.18s;
}
.reveal-btn:hover { border-color: var(--rec-red); color: var(--rec-red-dk); }
.reveal-btn.is-active { background: var(--light-peach); color: var(--rec-red-dk); border-color: transparent; }

/* Edited / Original segmented toggle (compare against ground truth) */
.src-toggle {
  margin-right: auto; display: inline-flex; padding: 3px; gap: 2px;
  background: var(--canvas); border: 1px solid var(--neutral-200); border-radius: 999px;
}
.src-toggle__btn {
  font-family: var(--font); font-size: 12.5px; font-weight: 600; cursor: pointer;
  padding: 6px 14px; border-radius: 999px; border: 0; background: transparent;
  color: var(--ink-soft); transition: background 0.18s, color 0.18s;
}
.src-toggle__btn:hover { color: var(--rec-red-dk); }
.src-toggle__btn.is-active { background: #fff; color: var(--edit-maroon); box-shadow: var(--shadow); }
/* the ground-truth footage carries no edits, so hide the markers */
.video-tile.is-original .region-badge,
.video-tile.is-original .scrubber__regions { display: none; }

/* ---------- alt-background section (full-bleed canvas) ---------- */
.section--alt { background: var(--canvas); max-width: none; }
.section--alt > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }

/* wide companion callout (spans the content column) */
.paper-callout { border-left: 4px solid var(--rec-red); }
.paper-callout--wide { margin-top: 28px; }
.paper-callout__links { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 4px; }

/* ---------- JUMPCUT ---------- */
.section--jumpcut { background: var(--canvas); max-width: none; }
.section--jumpcut > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.jc-compare { margin-top: 36px; }
.jc-picker { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.jc-pick {
  font-family: var(--font-mono); font-size: 12.5px; cursor: pointer;
  padding: 7px 14px; border-radius: 999px;
  background: #fff; color: var(--edit-maroon); border: 1px solid var(--neutral-200);
  transition: border-color 0.18s, color 0.18s, background 0.18s;
}
.jc-pick:hover { border-color: var(--rec-red); color: var(--rec-red-dk); }
.jc-pick.is-active { background: var(--edit-maroon); color: #fff; border-color: transparent; }

/* side-by-side pair */
.jc-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 720px) { .jc-pair { grid-template-columns: 1fr; } }
.jc-item { margin: 0; }
.jc-item__label {
  display: flex; align-items: baseline; gap: 9px; flex-wrap: wrap;
  font-size: 16px; font-weight: 600; color: var(--ink); margin-bottom: 10px;
}
.jc-item__sub {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--ink-faint); font-weight: 500;
}
.jc-dot { width: 10px; height: 10px; border-radius: 50%; align-self: center; }
.jc-dot--raw { background: var(--peach); }
.jc-dot--smooth { background: var(--rec-red); }
.video-tile--jc.jc-mode-smooth .ph-face__head { animation: none; }
.jc-note { max-width: var(--maxw-narrow); margin: 22px 0 0; color: var(--ink-soft); font-size: 15.5px; }

/* ---------- TABBED EXAMPLES (editing + translation) ---------- */
.tabbed { margin-top: 8px; }
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 18px; }
.tab {
  font-family: var(--font-mono); font-size: 13px; cursor: pointer;
  min-width: 38px; padding: 7px 13px; border-radius: 999px;
  background: #fff; color: var(--edit-maroon); border: 1px solid var(--neutral-200);
  transition: border-color 0.18s, color 0.18s, background 0.18s;
}
.tab:hover { border-color: var(--rec-red); color: var(--rec-red-dk); }
.tab.is-active { background: var(--edit-maroon); color: #fff; border-color: transparent; }
.tab-panel { display: none; }
.tab-panel.is-active { display: block; }

/* ---------- TRANSLATION pair ---------- */
.trans-ex { margin: 0; }
.trans-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
@media (max-width: 720px) { .trans-pair { grid-template-columns: 1fr; } }
.trans-item { display: flex; flex-direction: column; gap: 9px; }
.trans-cap {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--ink-faint);
}
.trans-cap--gen { color: var(--rec-red); }

/* ---------- SAMPLES (one per row) ---------- */
.sample-grid { display: flex; flex-direction: column; gap: 22px; }
.sample {
  background: #fff;
  border: 1px solid color-mix(in srgb, var(--rec-red) 18%, var(--line));
  border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow);
  transition: border-color 0.25s, box-shadow 0.25s;
}
.sample:hover { border-color: color-mix(in srgb, var(--rec-red) 38%, var(--line)); }
.sample__media { max-width: 760px; margin: 0 auto; }
.sample__bar {
  display: flex; align-items: center; justify-content: flex-end; gap: 12px;
  max-width: 760px; margin: 14px auto 0; flex-wrap: wrap;
}
.sample .transcript { max-width: 760px; margin: 16px auto 0; }

/* ---------- IMPACT ---------- */
.impact-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 820px) { .impact-cards { grid-template-columns: 1fr; } }
.impact-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow); transition: transform 0.18s, border-color 0.18s;
}
.impact-card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--rec-red) 40%, var(--line)); }
.impact-card h3 { font-size: 21px; font-weight: 700; color: var(--edit-maroon); margin: 0 0 12px; letter-spacing: -0.01em; }
.impact-card p { color: var(--ink-soft); margin: 0; font-size: 15px; }
.impact-card__link { margin-top: 12px !important; font-weight: 600; }
.impact-card__link a { color: var(--rec-red); text-decoration: none; }
.impact-card__link a:hover { color: var(--rec-red-dk); text-decoration: underline; }
.impact-note { max-width: var(--maxw-narrow); margin-top: 30px; }

/* ---------- CITATION ---------- */
.cite-block { position: relative; margin-top: 16px; }
.cite-block pre {
  margin: 0; padding: 18px; overflow-x: auto;
  background: var(--neutral-50); border: 1px solid var(--line); border-radius: 6px;
  font-family: var(--font-mono); font-size: 14px; line-height: 1.55; color: var(--ink);
}
.cite-copy {
  position: absolute; top: 12px; right: 12px; cursor: pointer;
  font-family: var(--font); font-size: 13px; font-weight: 600;
  padding: 6px 12px; border-radius: 999px; border: 1px solid var(--neutral-200);
  background: #fff; color: var(--edit-maroon); transition: 0.2s;
}
.cite-copy:hover { border-color: var(--rec-red); color: var(--rec-red-dk); }
.cite-copy.copied { background: var(--light-peach); color: var(--rec-red-dk); border-color: transparent; }

/* ---------- FOOTER ---------- */
.footer {
  max-width: var(--maxw); margin: 0 auto;
  padding: 36px clamp(18px, 4vw, 32px) 56px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  color: var(--ink-soft); font-size: 14px;
}
.footer__muted { color: var(--ink-faint); }
.footer a { color: var(--accent); }

@media (max-width: 560px) {
  body { font-size: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  html { scroll-behavior: auto; }
}