/* ==========================================================================
   CLIFT talk slides — same design system as the film and the project page.
   Fixed 1280x720 stage, scaled to the viewport. Print = one page per slide.
   ========================================================================== */

:root {
  --bg: #000000;
  --surface: #121a29;
  --surface-2: #161e2e;
  --border: #243044;
  --text: #e8edf5;
  --text-dim: #8da3c0;
  --text-faint: #7d8fa9;
  --brand: #5b9dff;
  --brand-bright: #7cb3ff;
  --brand2: #8b5cf6;
  --brand2-bright: #a78bfa;
  --pos: #34d399;
  --font: 'Inter', -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --mono: 'JetBrains Mono', 'SF Mono', Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  overflow: hidden;
}

/* ---------------- deck & stage ---------------- */

.slide {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
}
.slide.active { display: flex; }

.stage {
  position: relative;
  width: 1280px;
  height: 720px;
  padding: 186px 72px 52px;
  transform-origin: center center;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
/* pinned header: identical position on every content slide */
.stage > .kicker { position: absolute; top: 60px; left: 72px; right: 72px; margin: 0; text-align: center; }
.stage > .slide-h { position: absolute; top: 94px; left: 72px; right: 72px; margin: 0; text-align: center; }
/* full-bleed slides (title, statement, closing) keep symmetric padding */
.slide-full .stage { padding: 56px 72px; }

/* ---------------- shared type ---------------- */

.grad,
.grad-inline {
  background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-style: normal;
}

.kicker {
  margin: 0 0 10px;
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brand-bright);
}
.step-num {
  font-size: 30px;
  font-weight: 600;
  margin-right: 14px;
  vertical-align: -3px;
  background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.slide-h {
  margin: 0 0 30px;
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

/* ---------------- layouts ---------------- */

.cols { display: flex; gap: 48px; align-items: center; }
.cols .col-text { flex: 1; min-width: 0; }
.cols .col-media { flex: 1.1; min-width: 0; }
.cols-media-heavy .col-media { flex: 1.55; }
.cols-even { align-items: flex-start; }
.cols-even .col-media { flex: 1; }

.col-text ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.col-text li {
  position: relative;
  padding-left: 26px;
  margin-bottom: 20px;
  font-size: 21px;
  line-height: 1.5;
  color: #c9d3e4;
}
.col-text li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 12px;
  width: 12px;
  height: 2px;
  border-radius: 1px;
  background: linear-gradient(90deg, var(--brand), var(--brand2));
}
.col-text strong { color: var(--text); }
.col-text .pos { color: var(--pos); }

.note {
  margin: 26px 0 0;
  font-family: var(--mono);
  font-size: 15.5px;
  color: var(--text-dim);
}
.note.center { text-align: center; margin-top: 24px; }
.note-dim { color: var(--text-faint); }

/* media frames */
.clip {
  position: relative;
  aspect-ratio: 16 / 9;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid transparent;
  background:
    linear-gradient(#000, #000) padding-box,
    linear-gradient(135deg, rgba(124, 179, 255, 0.45), rgba(255, 255, 255, 0.10) 40%, rgba(167, 139, 250, 0.45)) border-box;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.55);
}
.clip video { display: block; width: 100%; height: 100%; object-fit: contain; }
.clip-wide { aspect-ratio: auto; }
.clip-43 { aspect-ratio: 4 / 3; max-width: 520px; margin: 0 auto; }
.clip-wide video { height: auto; }

.plate {
  background: #f2f2f2;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  padding: 12px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35), 0 24px 64px rgba(0, 0, 0, 0.45);
  max-height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.plate img {
  display: block;
  max-width: 100%;
  max-height: 470px;
  border-radius: 8px;
  filter: brightness(0.95) saturate(1.03);
}
.plate-photo {
  padding: 0;
  background:
    linear-gradient(#05070c, #05070c) padding-box,
    linear-gradient(135deg, rgba(124, 179, 255, 0.35), rgba(255, 255, 255, 0.08) 40%, rgba(167, 139, 250, 0.35)) border-box;
  border: 1px solid transparent;
}
.plate-photo img { border-radius: 13px; filter: none; }

.cap {
  margin: 12px 0 0;
  text-align: center;
  font-family: var(--mono);
  font-size: 14px;
  color: var(--text-dim);
}

/* horizontal bar chart (film results-bar grammar) */
.hchart { margin-top: 24px; }
.hlegend { display: flex; gap: 22px; margin-bottom: 14px; }
.hkey { display: inline-flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 13px; color: var(--text-dim); }
.hswatch { width: 18px; height: 8px; border-radius: 4px; }
.hswatch-grod { background: linear-gradient(90deg, var(--brand), var(--brand2)); }
.hswatch-pi { background: rgba(141, 163, 192, 0.45); }
.hgroup { margin-bottom: 14px; }
.hlabel { margin: 0 0 6px; font-size: 15px; font-weight: 600; color: #c9d3e4; }
.hrow { display: grid; grid-template-columns: 1fr 34px; align-items: center; gap: 10px; margin-bottom: 5px; }
.htrack { height: 11px; border-radius: 999px; background: rgba(141, 163, 192, 0.14); overflow: hidden; }
.hfill {
  display: block;
  height: 100%;
  width: 0;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--brand), var(--brand2));
  box-shadow: 0 0 10px rgba(91, 157, 255, 0.35);
  transition: width 1s cubic-bezier(0.22, 1, 0.36, 1) 0.15s;
}
.hfill-dim { background: rgba(141, 163, 192, 0.45); box-shadow: none; }
.slide.active .hfill { width: var(--w); }
.hval { font-family: var(--mono); font-size: 15px; color: var(--text-dim); text-align: right; font-variant-numeric: tabular-nums; }
.hfoot { margin: 10px 0 0; font-family: var(--mono); font-size: 12.5px; color: var(--text-faint); }
@media print { .hfill { width: var(--w) !important; transition: none; } }

/* code card (LLM fine-tune API mock) */
.code-card {
  border-radius: 16px;
  border: 1px solid transparent;
  background:
    linear-gradient(#0a0f18, #0a0f18) padding-box,
    linear-gradient(135deg, rgba(124, 179, 255, 0.45), rgba(255, 255, 255, 0.10) 40%, rgba(167, 139, 250, 0.45)) border-box;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.55);
  padding: 28px 32px;
}
.code-card pre {
  margin: 0;
  font-family: var(--mono);
  font-size: 16.5px;
  line-height: 1.75;
  color: #c9d3e4;
  white-space: pre-wrap;
}
.c-dim { color: var(--text-faint); }
.c-hl { color: var(--brand-bright); }
.c-str { color: var(--brand2-bright); }
.c-pos { color: var(--pos); font-weight: 600; }

/* two clips side by side */
.duo { display: flex; gap: 24px; align-items: flex-start; }
.duo > div { flex: 1; min-width: 0; }

/* failure-cause pills */
.pillrow { display: flex; align-items: center; justify-content: center; gap: 10px; flex-wrap: wrap; margin-top: 12px; }
.pill-tag { font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-faint); margin-right: 2px; }
.pill {
  font-family: var(--mono);
  font-size: 13.5px;
  color: #fda4af;
  background: rgba(251, 113, 133, 0.10);
  border: 1px solid rgba(251, 113, 133, 0.35);
  border-radius: 999px;
  padding: 4px 12px;
}

/* select-then-distill flow */
.flow { display: flex; align-items: center; gap: 20px; margin: 12px 0 8px; }
.flow-stage { flex: 1; min-width: 0; opacity: 0; transform: translateY(14px); transition: opacity 0.5s ease, transform 0.5s ease; }
.slide.active .flow-stage { opacity: 1; transform: none; }
.slide.active .flow-stage:nth-of-type(1) { transition-delay: 0.1s; }
.slide.active .flow-stage:nth-of-type(3) { transition-delay: 0.55s; }
.slide.active .flow-stage:nth-of-type(5) { transition-delay: 1.0s; }
.flow-arrow {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  color: var(--brand-bright);
  font-size: 30px;
  opacity: 0;
  transition: opacity 0.4s ease;
}
.slide.active .flow-arrow { opacity: 1; }
.slide.active .flow-arrow:nth-of-type(2) { transition-delay: 0.4s; }
.slide.active .flow-arrow:nth-of-type(4) { transition-delay: 0.85s; }
.flow-arrow span {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.flow-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 26px 26px 24px;
  min-height: 220px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}
.flow-card h3 { margin: 0 0 10px; font-family: var(--mono); font-size: 21px; font-weight: 600; color: var(--text); }
.flow-card p { margin: 0 0 16px; font-size: 16.5px; line-height: 1.55; color: var(--text-dim); }
.flow-card-hl {
  border: 1px solid transparent;
  background:
    linear-gradient(var(--surface-2), var(--surface-2)) padding-box,
    linear-gradient(135deg, rgba(124, 179, 255, 0.55), rgba(167, 139, 250, 0.55)) border-box;
}
.flow-card-hl h3 { background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chips span {
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text-dim);
  background: rgba(91, 157, 255, 0.08);
  border: 1px solid rgba(91, 157, 255, 0.30);
  border-radius: 999px;
  padding: 3px 12px;
}
.chips-pos span { color: #6ee7b7; background: rgba(52, 211, 153, 0.08); border-color: rgba(52, 211, 153, 0.30); }

/* A/B preference minis */
.ab-pair { display: flex; gap: 10px; margin: 2px 0 14px; }
.ab-pair > div { position: relative; flex: 1; min-width: 0; }
.ab-pair video { display: block; width: 100%; border-radius: 8px; border: 1px solid rgba(141, 163, 192, 0.25); }
.ab-good video { border-color: rgba(52, 211, 153, 0.45); }
.ab-bad video { border-color: rgba(251, 113, 133, 0.35); }
.ab-pair span {
  position: absolute;
  top: 6px;
  left: 8px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--text);
  background: rgba(0, 0, 0, 0.55);
  border-radius: 6px;
  padding: 1px 7px;
}

/* advantage labeling widgets */
.flow-eq { align-items: stretch; gap: 38px; }
.flow-eq .flow-stage { display: flex; }
.flow-eq .flow-card { height: 100%; width: 100%; display: flex; flex-direction: column; justify-content: flex-start; min-height: 360px; padding: 32px 32px 26px; }
.flow-eq .figzone { height: 150px; display: flex; flex-direction: column; justify-content: center; margin-bottom: 16px; }
.thumbrow { display: flex; gap: 10px; }
.thumb { flex: 1; min-width: 0; margin: 0; }
.thumb img { display: block; width: 100%; border-radius: 6px; border: 1px solid var(--border); }
.thumb-q img { border-color: transparent; outline: 1.5px dashed rgba(124, 179, 255, 0.7); outline-offset: 2px; }
.thumb figcaption { font-family: var(--mono); font-size: 11px; color: var(--text-faint); text-align: center; margin-top: 6px; }
.thumb-q figcaption { color: var(--brand-bright); }
.flow-eq .flow-card h3 { margin-bottom: 22px; }
.flow-eq .flow-card p { margin: 0; font-size: 16px; line-height: 1.5; }
.flow-eq .flow-arrow { align-self: center; }
.cardline { font-size: 16px !important; color: var(--text-dim) !important; line-height: 1.6 !important; }
.mini-fig { display: block; width: 100%; height: auto; margin: 0; }
.formula { font-family: var(--mono); font-size: 19px; color: var(--brand-bright); margin-bottom: 10px !important; }
.card-strip { display: block; width: 100%; border-radius: 8px; margin-top: 4px; }
.strip-caption { font-family: var(--mono); font-size: 12px !important; color: var(--text-faint) !important; margin: 8px 0 18px !important; text-align: center; }
.tokrow { display: flex; align-items: center; gap: 12px; margin-top: 14px; }
.tokrow .cardline { font-size: 14px !important; white-space: nowrap; }
.ladder { margin: 0; }
.ladder .lrow { padding: 3px 0; }
.ladder .lbar { display: block; height: 10px; border-radius: 999px; background: rgba(141, 163, 192, 0.30); }
.ladder .lrow-q { display: flex; align-items: center; gap: 10px; }
.ladder .lrow-q .lbar { outline: 1.5px dashed rgba(124, 179, 255, 0.7); outline-offset: 2px; flex: 0 0 auto; }
.ladder .lrow-q em { font-style: normal; font-family: var(--mono); font-size: 11px; color: var(--brand-bright); white-space: nowrap; }
.ladder .lbar.lpos { background: linear-gradient(90deg, var(--brand), var(--pos)); box-shadow: 0 0 8px rgba(52, 211, 153, 0.3); }
.pctline { position: relative; border-top: 1.5px dashed rgba(167, 139, 250, 0.6); margin: 8px 0; }
.pctline span {
  position: absolute;
  right: 0;
  top: -8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--brand2-bright);
  background: var(--surface-2);
  padding: 0 6px;
}
.tok-true { font-family: var(--mono); font-size: 14px; color: var(--pos); border: 1px solid rgba(52, 211, 153, 0.4); border-radius: 6px; padding: 1px 8px; white-space: nowrap; display: inline-flex; justify-content: center; min-width: 150px; box-sizing: border-box; }
.tok-false { font-family: var(--mono); font-size: 14px; color: #fda4af; border: 1px solid rgba(251, 113, 133, 0.35); border-radius: 6px; padding: 1px 8px; white-space: nowrap; display: inline-flex; justify-content: center; min-width: 150px; box-sizing: border-box; }

/* --- slides 20a/20b: base model matters --- */

/* 20a · same recipe, opposite outcomes — diverging slope */
.bm-wrap { width: 100%; }
.bm-cond {
  margin: 0 0 8px;
  text-align: center;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-dim);
}
.bmslope { display: block; width: 940px; height: 360px; margin: 0 auto; }
.sl-guide { stroke: rgba(36, 48, 68, 0.9); stroke-width: 1.5; stroke-dasharray: 3 6; }
.sl-axis { font-family: var(--mono); font-size: 13px; letter-spacing: 0.14em; text-transform: uppercase; fill: var(--text-faint); }
.sl-label { font-family: var(--font); font-size: 17px; font-weight: 600; fill: var(--text); dominant-baseline: central; }
.sl-label .sl-base { font-family: var(--mono); font-size: 14px; font-weight: 500; fill: var(--text-dim); }
.sl-label .sl-sub { font-size: 11px; }
.sl-line { fill: none; stroke-width: 4; stroke-linecap: round; stroke-dasharray: 570; stroke-dashoffset: 570; transition: stroke-dashoffset 0.9s cubic-bezier(0.22, 1, 0.36, 1); }
.sl-grod .sl-line { stroke: var(--pos); }
.sl-pi .sl-line { stroke: #fb7185; }
.sl-grod .sl-dot0 { fill: rgba(52, 211, 153, 0.5); }
.sl-pi .sl-dot0 { fill: rgba(251, 113, 133, 0.5); }
.sl-grod .sl-dot { fill: var(--pos); }
.sl-pi .sl-dot { fill: #fb7185; }
.sl-grod .sl-halo { fill: rgba(52, 211, 153, 0.16); }
.sl-pi .sl-halo { fill: rgba(251, 113, 133, 0.16); }
.sl-big { font-family: var(--mono); font-size: 54px; font-weight: 600; letter-spacing: -2px; dominant-baseline: central; }
.sl-grod .sl-big { fill: var(--pos); filter: drop-shadow(0 0 14px rgba(52, 211, 153, 0.35)); }
.sl-pi .sl-big { fill: #fda4af; filter: drop-shadow(0 0 14px rgba(251, 113, 133, 0.3)); }
.sl-verdict { font-family: var(--mono); font-size: 13px; letter-spacing: 0.16em; text-transform: uppercase; }
.sl-grod .sl-verdict { fill: rgba(52, 211, 153, 0.9); }
.sl-pi .sl-verdict { fill: rgba(253, 164, 175, 0.9); }
.sl-cap { opacity: 0; transition: opacity 0.45s ease; }
.slide.active .sl-grod .sl-line { stroke-dashoffset: 0; transition-delay: 0.3s; }
.slide.active .sl-grod .sl-cap { opacity: 1; transition-delay: 1.0s; }
.slide.active .sl-pi .sl-line { stroke-dashoffset: 0; transition-delay: 1.15s; }
.slide.active .sl-pi .sl-cap { opacity: 1; transition-delay: 1.85s; }
.bm-coda { margin: 12px 0 0; text-align: center; font-size: 22px; font-weight: 600; letter-spacing: -0.01em; color: var(--text); opacity: 0; transition: opacity 0.6s ease; }
.slide.active .bm-coda { opacity: 1; transition-delay: 2.5s; }

/* 20b · why the collapse — full-width filmstrip + callback stat */
.failstrip { display: flex; align-items: flex-start; justify-content: center; gap: 18px; }
.fs-frame { position: relative; margin: 0; flex: 1; min-width: 0; opacity: 0; transform: translateY(10px); transition: opacity 0.5s ease, transform 0.5s ease; }
.fs-frame img { display: block; width: 100%; border-radius: 10px; border: 1px solid var(--border); }
.fs-frame figcaption { margin: 10px 2px 0; font-family: var(--mono); font-size: 14.5px; text-align: center; color: var(--text-dim); }
.fs-fail img { border: 2px solid rgba(251, 113, 133, 0.75); box-shadow: 0 0 32px rgba(251, 113, 133, 0.18); }
.fs-fail figcaption { color: #fda4af; font-weight: 600; }
.fs-tag { position: absolute; top: 10px; right: 10px; font-family: var(--mono); font-size: 13px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: #fda4af; background: rgba(0, 0, 0, 0.68); border: 1px solid rgba(251, 113, 133, 0.5); border-radius: 6px; padding: 4px 10px; opacity: 0; transform: scale(0.85); transition: opacity 0.35s ease, transform 0.35s cubic-bezier(0.22, 1, 0.36, 1); }
.fs-arrow { flex: 0 0 auto; margin-top: 104px; color: var(--text-faint); font-size: 22px; opacity: 0; transition: opacity 0.4s ease; }
.slide.active .failstrip > .fs-frame:nth-of-type(1) { opacity: 1; transform: none; transition-delay: 0.15s; }
.slide.active .failstrip > .fs-arrow:nth-of-type(1) { opacity: 1; transition-delay: 0.5s; }
.slide.active .failstrip > .fs-frame:nth-of-type(2) { opacity: 1; transform: none; transition-delay: 0.65s; }
.slide.active .failstrip > .fs-arrow:nth-of-type(2) { opacity: 1; transition-delay: 1.0s; }
.slide.active .failstrip > .fs-frame:nth-of-type(3) { opacity: 1; transform: none; transition-delay: 1.15s; }
.slide.active .fs-tag { opacity: 1; transform: none; transition-delay: 1.7s; }
.bm-after { margin: 26px 0 0; display: flex; flex-direction: column; align-items: center; gap: 8px; opacity: 0; transition: opacity 0.5s ease; }
.slide.active .bm-after { opacity: 1; transition-delay: 2.2s; }
.bm-after-cap { font-family: var(--mono); font-size: 13.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-dim); }
.bm-pair { display: flex; align-items: baseline; gap: 14px; }
.bm-name { font-family: var(--mono); font-size: 16px; color: var(--text-dim); }
.bm-num { font-family: var(--mono); font-size: 42px; font-weight: 600; letter-spacing: -1px; color: var(--text); font-variant-numeric: tabular-nums; }
.bm-vs { font-family: var(--mono); font-size: 14px; color: var(--text-faint); margin: 0 6px; }
.bm-num-neg { color: #fda4af; text-shadow: 0 0 20px rgba(251, 113, 133, 0.25); }
.bm-hyp { margin: 22px 0 0; text-align: center; font-family: var(--mono); font-size: 13.5px; color: var(--text-faint); opacity: 0; transition: opacity 0.5s ease; }
.slide.active .bm-hyp { opacity: 1; transition-delay: 2.7s; }
.hypk { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-faint); }
@media print, (prefers-reduced-motion: reduce) {
  .sl-line { stroke-dashoffset: 0 !important; transition: none !important; }
  .sl-cap, .fs-frame, .fs-arrow, .fs-tag, .bm-after, .bm-hyp, .bm-coda { opacity: 1 !important; transform: none !important; transition: none !important; }
}

/* mini table */
.mini-table {
  margin-top: 26px;
  border-collapse: collapse;
  font-size: 18px;
  width: 100%;
}
.mini-table th, .mini-table td {
  padding: 8px 14px;
  text-align: right;
  border-bottom: 1px solid rgba(36, 48, 68, 0.7);
  font-variant-numeric: tabular-nums;
}
.mini-table th:first-child, .mini-table td:first-child { text-align: left; }
.mini-table th {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-dim);
  font-weight: 600;
}
.mini-table tr.hl td { background: linear-gradient(90deg, rgba(91, 157, 255, 0.13), rgba(91, 157, 255, 0.02)); color: var(--text); font-weight: 600; }
.mini-table tr:last-child td { border-bottom: none; color: var(--text-dim); }

/* ---------------- title & statement slides ---------------- */

.center-col {
  position: relative;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.glow {
  position: absolute;
  inset: -60px;
  pointer-events: none;
  background:
    radial-gradient(700px 420px at 50% 30%, rgba(91, 157, 255, 0.16) 0%, rgba(91, 157, 255, 0.05) 45%, transparent 74%),
    radial-gradient(600px 380px at 72% 76%, rgba(139, 92, 246, 0.10) 0%, transparent 72%);
}
.wordmark {
  margin: 0 0 18px;
  font-size: 110px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  filter: drop-shadow(0 0 26px rgba(91, 157, 255, 0.30));
}
.deck-line {
  margin: 0 0 30px;
  font-size: 27px;
  font-weight: 600;
  line-height: 1.45;
  color: #dce4f2;
}
.deck-line strong { color: var(--text); }
.authors { margin: 0 0 10px; font-size: 17px; font-weight: 500; color: #b9c5da; line-height: 1.7; }
.authors sup { color: var(--text-faint); font-size: 11px; }
.affils { margin: 0 0 30px; font-family: var(--mono); font-size: 14px; color: var(--text-dim); }
.affils sup { color: var(--text-faint); }
.logo-row { display: flex; align-items: center; justify-content: center; gap: 44px; }
.logo-row img { filter: brightness(0) invert(0.78); opacity: 0.8; }

.statement h2 {
  margin: 0 0 26px;
  font-size: 52px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.22;
}
.statement .sub { margin: 0; font-size: 23px; line-height: 1.6; color: var(--text-dim); }
.big-q { font-size: 62px !important; }

/* ---------------- results tiles ---------------- */

.tiles { display: flex; gap: 24px; }
.tile {
  flex: 1;
  background: linear-gradient(180deg, var(--surface-2), var(--surface) 60%);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}
.tile video { display: block; width: 100%; aspect-ratio: 25 / 16; object-fit: cover; background: #000; }
.tile-name { margin: 14px 18px 4px; font-size: 17px; font-weight: 700; }
.tile-nums { margin: 0 18px 16px; display: flex; align-items: baseline; gap: 10px; }
.tile-nums .base { font-family: var(--mono); font-size: 18px; color: var(--text-faint); }
.tile-nums .arr { color: var(--text-faint); }
.credit { color: var(--text-faint); font-size: 13px; }
.tile-nums .fin {
  font-family: var(--mono);
  font-size: 38px;
  font-weight: 600;
  letter-spacing: -1px;
  color: var(--pos);
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 22px rgba(52, 211, 153, 0.25);
}

/* ---------------- HUD ---------------- */

.hud {
  position: fixed;
  right: 18px;
  bottom: 14px;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 10px;
  opacity: 0.4;
  transition: opacity 0.2s;
}
.hud:hover { opacity: 1; }
.hud-btn {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  font-size: 15px;
  cursor: pointer;
}
.hud-btn:hover { color: var(--text); border-color: rgba(91, 157, 255, 0.55); }
.hud-count { font-family: var(--mono); font-size: 13px; color: var(--text-faint); min-width: 56px; text-align: center; }

.deck-progress {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  z-index: 10;
  background: rgba(36, 48, 68, 0.4);
}
.deck-progress i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--brand), var(--brand2));
  transition: width 0.25s ease;
}

.print-poster { display: none; }

/* ---------------- print: one page per slide ---------------- */

@page { size: 1280px 720px; margin: 0; }
@media print {
  html, body { overflow: visible; height: auto; background: var(--bg); }
  .slide {
    display: flex !important;
    position: relative;
    inset: auto;
    width: 1280px;
    height: 720px;
    page-break-after: always;
    break-after: page;
  }
  .stage { transform: none !important; }
  .hud, .deck-progress { display: none !important; }
  .clip video, .tile video { display: none; }
  .clip .print-poster { display: block; width: 100%; height: 100%; object-fit: contain; }
  .tile .print-poster { display: block; width: 100%; aspect-ratio: 25 / 16; object-fit: cover; }
}

/* ==========================================================================
   Method-part expansion: problem setting, roadmap, zoom-ins, recap
   ========================================================================== */

/* code cards */
.c-neg { color: #fda4af; }
.code-card-sm { padding: 22px 26px; }
.code-card-sm pre { font-size: 14px; line-height: 1.62; }

/* objective / formula card */
.obj-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 30px 40px 26px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}
.obj-formula {
  margin: 0 0 6px;
  text-align: center;
  font-family: var(--mono);
  font-size: 25px;
  line-height: 1.6;
  color: var(--text);
}
.obj-formula sub, .obj-formula sup { font-size: 60%; }
.obj-r { color: var(--brand-bright); }
.obj-kl { color: var(--brand2-bright); }
.obj-legend { display: flex; flex-direction: column; gap: 9px; margin-top: 18px; align-items: center; }
.obj-key { display: inline-flex; align-items: baseline; gap: 10px; font-size: 16.5px; color: var(--text-dim); }
.obj-key strong { color: #c9d3e4; }
.obj-swatch { flex: 0 0 auto; width: 16px; height: 7px; border-radius: 4px; transform: translateY(-2px); }
.obj-swatch-r { background: var(--brand-bright); }
.obj-swatch-kl { background: var(--brand2-bright); }
.obj-card-sm { padding: 22px 26px 18px; }
.obj-card-sm .obj-formula { font-size: 21px; margin: 2px 0; }
.obj-note { font-family: var(--mono); font-size: 13px; color: var(--text-faint); }

/* "not exposed" rows */
.lockrow { display: flex; gap: 18px; margin-top: 22px; }
.lockitem {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 15px 18px 13px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
}
.lockhead { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.lockname { font-family: var(--mono); font-size: 16px; font-weight: 600; color: var(--text); white-space: nowrap; }
.lockneed { font-size: 14.5px; color: var(--text-dim); }
.lockx {
  font-family: var(--mono);
  font-size: 12.5px;
  color: #fda4af;
  border: 1px solid rgba(251, 113, 133, 0.35);
  border-radius: 999px;
  padding: 2px 10px;
  white-space: nowrap;
}

/* roadmap (4-stage flow) */
.flow-road .road-card { min-height: 195px; padding: 22px 22px 20px; }
.road-card h3 { font-family: var(--font); font-size: 20px; font-weight: 700; }
.road-card h3 .step-num { font-size: 24px; margin-right: 10px; }
.road-card p { font-size: 15.5px; margin-bottom: 0; }
.slide.active .flow-arrow:nth-of-type(6) { transition-delay: 1.3s; }
.slide.active .flow-stage:nth-of-type(7) { transition-delay: 1.45s; }
.loop-note { margin: 24px 0 0; text-align: center; font-family: var(--mono); font-size: 15px; color: var(--text-dim); }

/* score: two-options-combine layout */
.flow-s1 { align-items: stretch; }
.flow-s1 .flow-arrow { align-self: center; }
.stack2 { display: flex; flex-direction: column; gap: 16px; flex: 1.25; }
.stack2 .flow-card { min-height: 0; flex: 1; padding: 20px 24px 18px; }
.stack2 .flow-card p { margin-bottom: 12px; }
.flow-s1 .s1-res { height: 100%; min-height: 0; display: flex; flex-direction: column; justify-content: center; }
.vrow { display: flex; gap: 10px; flex-wrap: wrap; }
.v-pro, .v-con { font-family: var(--mono); font-size: 13px; border-radius: 999px; padding: 3px 11px; }
.v-pro { color: #6ee7b7; border: 1px solid rgba(52, 211, 153, 0.35); }
.v-con { color: #fda4af; border: 1px solid rgba(251, 113, 133, 0.35); }

/* slimmer flow-eq cards (zoom-in slides) */
.flow-eq-slim .flow-card { min-height: 300px; padding: 28px 28px 22px; }
.flow-eq-slim .flow-card h3 { margin-bottom: 16px; }
.flow-eq-slim .formula { margin-bottom: 14px !important; font-size: 16px; white-space: nowrap; }
.figzone-sm { height: 118px !important; margin-bottom: 12px !important; }

/* state-difficulty ladder pair */
.duo-sm { display: flex; gap: 16px; }
.lad-card { flex: 1; min-width: 0; min-height: 0; padding: 20px 22px 16px; }
.lad-card h3 { font-size: 17px; margin-bottom: 2px; }
.lad-card .cardline { font-size: 13px !important; margin-bottom: 12px !important; }
.lad-card .tokrow { margin-top: 14px; justify-content: center; }

/* dataset composition tiles */
.dsrow { display: flex; gap: 18px; align-items: stretch; }
.dsrow .ds-card { flex: 1; min-width: 0; min-height: 0; padding: 22px 20px 18px; }
.ds-card h3 { font-size: 18px !important; margin-bottom: 14px !important; }
.ds-prompt { font-family: var(--mono); font-size: 14px; color: #c9d3e4; line-height: 2.1; margin: 0 0 12px !important; }
.tok-sm { font-size: 12.5px !important; min-width: 0 !important; padding: 1px 8px !important; }
.tok-none {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--text-faint);
  border: 1px dashed rgba(141, 163, 192, 0.45);
  border-radius: 6px;
  padding: 1px 8px;
  white-space: nowrap;
  display: inline-flex;
}
.ds-skip { opacity: 0.72; }
.ds-skip .ds-prompt s { text-decoration-color: rgba(251, 113, 133, 0.6); }

/* wider value column for "≈100" */
.hchart-wide .hrow { grid-template-columns: 1fr 48px; }

/* condition: mode-selection figure */
.modes-fig { padding: 6px 0; }
.modes-fig svg { display: block; width: 100%; height: auto; }

/* iterate: stat rail */
.stat-rail { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 18px; }
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 13px 16px 11px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stat-num {
  font-family: var(--mono);
  font-size: 29px;
  font-weight: 600;
  letter-spacing: -1px;
  background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-label { font-family: var(--mono); font-size: 12.5px; color: var(--text-dim); }

/* recap */
.plate-recap { max-height: 420px; }
.plate-recap img { max-height: 330px; }
.check-rail { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 18px; }
.chk {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--text-dim);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 13px;
  white-space: nowrap;
}
.chk i { font-style: normal; color: var(--pos); margin-right: 8px; }

/* make staged flows visible in print / reduced motion (also fixes existing flow slides) */
@media print, (prefers-reduced-motion: reduce) {
  .flow-stage, .flow-arrow { opacity: 1 !important; transform: none !important; transition: none !important; }
}

/* ==========================================================================
   Dark-converted paper figures, results-chart highlighting, closing links
   ========================================================================== */

/* figures recolored for dark background — no plate needed */
.fig-dark { display: block; width: 100%; height: auto; }
.fig-reward { width: 96%; margin: 0 auto; }
.fig-teaser { width: 92%; margin: 0 auto; }
.fig-teaser-sm { width: 66%; margin: 0 auto; }

/* setup slide: give the task-suite figure the larger share */
.cols-setup { gap: 40px; align-items: center; }
.cols-setup .col-media:first-child { flex: 0.72; }
.cols-setup .col-media:last-child { flex: 1.5; }

/* results chart with per-slide focus overlays */
.rwrap { position: relative; width: 100%; }
.rwrap img { display: block; width: 100%; height: auto; }
.rdim {
  position: absolute;
  top: 32%;
  height: 65.2%;
  background: rgba(0, 0, 0, 0.56);
  border-radius: 4px;
  opacity: 0;
  transition: opacity 0.7s ease 0.5s;
}
.slide.active .rdim { opacity: 1; }
.rspot {
  position: absolute;
  top: 30.6%;
  height: 67.4%;
  border: 1.5px solid rgba(124, 179, 255, 0.85);
  border-radius: 8px;
  box-shadow: 0 0 22px rgba(91, 157, 255, 0.28), inset 0 0 16px rgba(91, 157, 255, 0.08);
  opacity: 0;
  transition: opacity 0.6s ease 0.9s;
}
.slide.active .rspot { opacity: 1; }
.rstats { display: flex; justify-content: center; gap: 40px; margin-top: 16px; }
.rstat { font-family: var(--mono); font-size: 15px; color: var(--text-dim); }
.rstat i { font-style: normal; color: var(--text-faint); }
.rstat b {
  font-size: 25px;
  font-weight: 600;
  color: var(--pos);
  margin-left: 3px;
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 16px rgba(52, 211, 153, 0.25);
}
.rwrap + .rstats + .note.center { margin-top: 14px; }
@media print, (prefers-reduced-motion: reduce) {
  .rdim, .rspot { opacity: 1 !important; transition: none !important; }
}

/* closing slide: QR trio + compact title block */
.wordmark-sm { font-size: 96px; margin-bottom: 12px; }
.deck-line-sm { font-size: 26px; margin-bottom: 20px; }
.authors-sm { font-size: 17px; line-height: 1.6; margin-bottom: 26px; }
.qr-row { display: flex; justify-content: center; gap: 68px; margin: 4px 0 0; }
.qr { margin: 0; }
.qr img {
  display: block;
  width: 172px;
  height: 172px;
  border-radius: 12px;
  border: 1px solid var(--border);
}
.qr figcaption {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 15px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  text-align: center;
}
.logo-row-sm { gap: 40px; }


/* --- acknowledgments --- */
.ack-wrap { max-width: 1000px; margin: 0 auto; width: 100%; }
.ack-lead { text-align: center; font-size: 22px; font-weight: 500; color: #dce4f2; margin: 0 0 44px; }
.ack-lead img { display: block; margin: 0 auto 18px; height: 42px; filter: brightness(0) invert(0.85); opacity: 0.9; }
.ack-lead strong { color: var(--text); }
.ack-row { display: flex; gap: 26px; }
.ack-tile {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px 24px 28px;
  text-align: center;
}
.ack-num {
  margin: 0 0 10px;
  font-family: var(--mono);
  font-size: 66px;
  font-weight: 600;
  line-height: 1;
  background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.ack-label { margin: 0 0 6px; font-size: 18px; font-weight: 700; color: var(--text); }
.ack-sub { margin: 0; font-family: var(--mono); font-size: 13.5px; line-height: 1.55; color: var(--text-dim); }


/* --- what's next: RL pyramid --- */
.pyr-sub {
  margin: 0 0 16px;
  text-align: center;
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
}
.pyr-sub em { font-style: normal; font-weight: 800; }
.pyr-v-reason { color: var(--brand); }
.pyr-v-act { color: #22d3ee; }
.pyr-v-self { color: #fbbf24; }
.pyr-cols { display: flex; gap: 36px; align-items: flex-start; }
.pyr-media { flex: 0 0 603px; }
.pyr-media img { display: block; width: 100%; }
.pyr-right { flex: 1; min-width: 0; position: relative; height: 430px; }
/* rows registered to the pyramid's layer bands (band centers at 100 / 211 / 330 px) */
.pyr-row { position: absolute; left: 0; right: 0; }
.pyr-row-top { top: 89px; }
.pyr-row-mid { top: 200px; }
.pyr-row-base { top: 319px; }
.pyr-tag {
  margin: 0 0 4px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text);
  line-height: 22px;
}
.pyr-dot { width: 10px; height: 10px; border-radius: 50%; flex: 0 0 auto; }
.pyr-tag-top .pyr-dot { background: #fbbf24; box-shadow: 0 0 10px rgba(251, 191, 36, 0.6); }
.pyr-tag-mid .pyr-dot { background: #22d3ee; box-shadow: 0 0 10px rgba(34, 211, 238, 0.6); }
.pyr-tag-base .pyr-dot { background: var(--brand); box-shadow: 0 0 10px rgba(91, 157, 255, 0.6); }
/* leader lines: from each dot back to that layer's sloped edge on the pyramid */
.pyr-row::before {
  content: "";
  position: absolute;
  top: 10px;
  height: 2px;
  right: calc(100% + 1px);
  border-radius: 1px;
}
.pyr-row-top::before { width: 288px; background: linear-gradient(90deg, rgba(251, 191, 36, 0), rgba(251, 191, 36, 0.7) 25%); }
.pyr-row-mid::before { width: 200px; background: linear-gradient(90deg, rgba(34, 211, 238, 0), rgba(34, 211, 238, 0.7) 25%); }
.pyr-row-base::before { width: 110px; background: linear-gradient(90deg, rgba(91, 157, 255, 0), rgba(91, 157, 255, 0.7) 25%); }
.pyr-chip {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: #fff;
  background-image: linear-gradient(105deg, var(--brand), var(--brand2));
  border-radius: 999px;
  padding: 3px 12px;
  margin-left: 6px;
  box-shadow: 0 0 16px rgba(91, 157, 255, 0.45);
}
.pyr-txt { margin: 0 0 0 20px; font-size: 15px; line-height: 1.5; color: #a9bcd8; }
/* the agentic thread: one spine through all three dots, down to the caption */
.pyr-spine {
  position: absolute;
  left: 3.5px;
  top: 58px;
  width: 3px;
  height: 344px;
  border-radius: 2px;
  background: linear-gradient(180deg, rgba(251, 191, 36, 0.95), rgba(34, 211, 238, 0.85) 42%, rgba(91, 157, 255, 0.85) 78%, rgba(139, 92, 246, 0.95));
  box-shadow: 0 0 12px rgba(91, 157, 255, 0.45);
}
/* arrowhead at the top: the thread drives capability upward */
.pyr-spine::before {
  content: '';
  position: absolute;
  top: -11px;
  left: -5px;
  border-left: 6.5px solid transparent;
  border-right: 6.5px solid transparent;
  border-bottom: 12px solid rgba(251, 191, 36, 0.95);
  filter: drop-shadow(0 0 6px rgba(251, 191, 36, 0.6));
}
/* upward chevrons in the gaps between rungs */
.pyr-chevron {
  position: absolute;
  left: 0.5px;
  width: 9px;
  height: 9px;
  border-left: 2.5px solid rgba(230, 238, 250, 0.9);
  border-top: 2.5px solid rgba(230, 238, 250, 0.9);
  transform: rotate(45deg);
  filter: drop-shadow(0 0 4px rgba(148, 190, 255, 0.5));
}
.pyr-thread { position: absolute; left: 0; right: 0; top: 392px; }
.pyr-thread::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 6px;
  width: 7px;
  height: 7px;
  transform: rotate(45deg);
  background: var(--brand2-bright);
  box-shadow: 0 0 10px rgba(167, 139, 250, 0.7);
}
.pyr-thread-k {
  margin: 0 0 3px 20px;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  background-image: linear-gradient(105deg, var(--brand-bright), var(--brand2-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.pyr-thread-t { margin: 0 0 0 20px; font-size: 14.5px; line-height: 1.5; color: var(--text-dim); }
/* staged reveal: pyramid + tagline, then rungs bottom-up, then the thread */
.pyr-media img, .pyr-sub { opacity: 0; transition: opacity 0.6s ease; }
.pyr-row { opacity: 0; transform: translateX(14px); transition: opacity 0.45s ease, transform 0.45s cubic-bezier(0.22, 1, 0.36, 1); }
.pyr-spine, .pyr-thread { opacity: 0; transition: opacity 0.5s ease; }
.slide.active .pyr-media img { opacity: 1; transition-delay: 0.05s; }
.slide.active .pyr-sub { opacity: 1; transition-delay: 0.2s; }
.slide.active .pyr-row-base { opacity: 1; transform: none; transition-delay: 0.55s; }
.slide.active .pyr-row-mid { opacity: 1; transform: none; transition-delay: 0.9s; }
.slide.active .pyr-row-top { opacity: 1; transform: none; transition-delay: 1.25s; }
.slide.active .pyr-spine { opacity: 1; transition-delay: 1.6s; }
.slide.active .pyr-thread { opacity: 1; transition-delay: 1.75s; }
@media print, (prefers-reduced-motion: reduce) {
  .pyr-media img, .pyr-sub, .pyr-row, .pyr-spine, .pyr-thread { opacity: 1 !important; transform: none !important; transition: none !important; }
}


/* sim-learning mini clip on the ACT rung */
.pyr-sim { position: absolute; right: 0; top: -10px; width: 196px; }
.pyr-sim video {
  display: block;
  width: 100%;
  border-radius: 8px;
  border: 1px solid rgba(34, 211, 238, 0.45);
  box-shadow: 0 0 18px rgba(34, 211, 238, 0.15);
}
.pyr-sim p {
  margin: 5px 0 0;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: center;
  color: rgba(34, 211, 238, 0.75);
}