/* ───── PART 1 — A/B choice ───── */
  .choice-stage {
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 60px;
    position: relative;
  }
  .choice {
    border: 1px solid var(--rule);
    padding: 56px 48px 44px;
    border-radius: 2px;
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 700ms ease, transform 700ms cubic-bezier(.2,.8,.2,1), border-color 500ms ease, background 500ms ease;
    min-height: 380px;
    display: flex;
    flex-direction: column;
    position: relative;
  }
  .choice.show { opacity: 1; transform: translateY(0); }
  #slide-ab .choice.show:hover {
    border-color: var(--gold);
    background: color-mix(in oklab, var(--gold) 10%, transparent);
    transform: translateY(-8px);
  }
  #slide-ab .choice.show {
    cursor: pointer;
  }
  :root[data-presenter] #slide-ab .choice.show {
    cursor: default;
    pointer-events: none;
  }
  #slide-ab .choice.is-selected {
    border-color: var(--gold);
    background: color-mix(in oklab, var(--gold) 12%, transparent);
  }
  #slide-ab .choice.is-selected::after {
    content: "";
    position: absolute;
    top: 26px;
    right: 28px;
    width: 34px;
    height: 34px;
    border: 1px solid var(--gold);
    border-radius: 2px;
  }
  #slide-ab .choice.is-selected::before {
    content: "";
    position: absolute;
    top: 36px;
    right: 37px;
    width: 17px;
    height: 9px;
    border-left: 3px solid var(--gold);
    border-bottom: 3px solid var(--gold);
    transform: rotate(-45deg);
    z-index: 1;
  }
  #slide-ab .choice.is-selected::after,
  #slide-ab .choice.is-selected::before {
    color: var(--gold);
  }
  #slide-ab .choice.show:hover .ev {
    border-top-color: var(--gold);
  }
  .choice .letter {
    font-family: var(--f-serif);
    font-style: italic;
    font-size: 120px;
    line-height: 0.9;
    color: var(--gold);
    margin-bottom: 20px;
  }
  .choice .prob {
    font-family: var(--f-mono);
    font-size: 32px;
    color: var(--ink-dim);
    letter-spacing: 0.02em;
  }
  .choice .amount {
    font-size: 60px;
    font-weight: 600;
    margin-top: 10px;
    letter-spacing: -0.03em;
  }
  .choice .ev {
    margin-top: auto;
    padding-top: 32px;
    border-top: 1px solid var(--rule);
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    font-family: var(--f-mono);
    font-size: 24px;
    color: var(--ink-mute);
  }
  .choice .ev-val { color: var(--ink); font-size: 32px; font-weight: 500; }

  .reveal-line {
    margin-top: 80px;
    font-size: 34px;
    color: var(--ink-dim);
    opacity: 0;
    transition: opacity 700ms ease;
    font-family: var(--f-sans);
    text-align: center;
    width: 100%;
  }
  .reveal-line.show { opacity: 1; }
  .reveal-line b { color: var(--gold); font-weight: 600; }

  .ab-result-panel {
    position: absolute;
    top: 26px;
    right: 28px;
    width: 120px;
    height: 138px;
    display: none;
    flex-direction: column;
    align-items: flex-end;
    justify-content: flex-start;
    gap: 10px;
    pointer-events: none;
  }
  :root[data-presenter] #slide-ab[data-has-votes="true"] .ab-result-panel {
    display: flex;
  }
  .ab-stack {
    width: 120px;
    min-height: 88px;
    display: grid;
    grid-template-columns: repeat(6, 12px);
    grid-auto-rows: 12px;
    align-content: start;
    justify-content: end;
    gap: 4px;
  }
  .ab-vote-square {
    width: 12px;
    height: 12px;
    border-radius: 2px;
    background: var(--gold);
    box-shadow: 0 0 0 1px color-mix(in oklab, var(--gold) 45%, transparent);
  }
  .ab-result-panel[data-result-choice="B"] .ab-vote-square {
    background: var(--blue);
    box-shadow: 0 0 0 1px color-mix(in oklab, var(--blue) 45%, transparent);
  }
  .ab-result-count {
    min-width: 76px;
    text-align: right;
    font-family: var(--f-mono);
    color: var(--ink-mute);
    font-size: 18px;
    letter-spacing: 0.04em;
  }
  .ab-result-count b {
    display: inline;
    color: var(--ink);
    font-size: 30px;
    line-height: 1.1;
    margin-right: 6px;
  }
  .ab-vote-status {
    margin-top: 24px;
    min-height: 32px;
    font-family: var(--f-mono);
    font-size: 20px;
    color: var(--ink-mute);
    letter-spacing: 0.04em;
    text-align: center;
  }
  .ab-vote-status b {
    color: var(--gold);
    font-weight: 600;
  }
  :root[data-presenter] #slide-ab .ab-vote-status {
    color: var(--ink-dim);
  }
  .ab-vote-guide {
    position: absolute;
    top: 178px;
    left: 50%;
    transform: translate(-50%, -8px);
    padding: 12px 18px;
    border: 1px solid var(--gold);
    border-radius: 2px;
    background: color-mix(in oklab, var(--bg) 90%, transparent);
    color: var(--gold);
    font-family: var(--f-mono);
    font-size: 20px;
    letter-spacing: 0.06em;
    opacity: 0;
    pointer-events: none;
    transition: opacity 520ms ease, transform 520ms cubic-bezier(.2,.8,.2,1);
    z-index: 6;
  }
  .ab-vote-guide.show {
    opacity: 1;
    transform: translate(-50%, 0);
  }

  /* ───── PART 2 — timeline ───── */
  .timeline {
    margin-top: 80px;
    position: relative;
    width: calc(100% - 60px);
    margin-left: 30px;
    height: 360px;
  }
  .timeline-axis {
    position: absolute;
    left: 0; right: 0;
    /* tl-year (~36px) + 36px margin-top + 8px (half dot) = ~80px → adjust to sit under dot center */
    top: 80px;
    height: 1px;
    background: var(--rule);
    z-index: 1;
  }
  .timeline-axis::after {
    content: "";
    position: absolute;
    top: 0; left: 0;
    height: 1px;
    width: 0;
    background: var(--gold);
    animation: axis-grow 2800ms cubic-bezier(.2,.8,.2,1) forwards;
    animation-delay: 200ms;
  }
  @keyframes axis-grow { to { width: 100%; } }

  .tl-node {
    position: absolute;
    top: 0;
    transform: translateX(-50%);
    width: 320px;
    opacity: 0;
    animation: tl-fade 700ms ease forwards;
  }
  .tl-node:nth-child(2) { left: 14%; animation-delay: 600ms; }
  .tl-node:nth-child(3) { left: 38%; animation-delay: 1400ms; }
  .tl-node:nth-child(4) { left: 64%; animation-delay: 2200ms; }
  .tl-node:nth-child(5) { left: 88%; animation-delay: 3000ms; }
  @keyframes tl-fade { to { opacity: 1; } }

  .tl-year {
    font-family: var(--f-mono);
    font-size: 28px;
    color: var(--gold);
    letter-spacing: 0.04em;
    text-align: center;
  }
  .tl-dot {
    width: 16px; height: 16px;
    background: var(--gold);
    border-radius: 50%;
    margin: 36px auto 36px;
    box-shadow: 0 0 0 6px var(--bg);
    position: relative;
    z-index: 2;
  }
  .tl-label {
    font-size: 28px;
    color: var(--ink);
    font-weight: 500;
    text-align: center;
    line-height: 1.3;
  }
  .tl-sub {
    margin-top: 8px;
    font-size: 24px;
    color: var(--ink-mute);
    text-align: center;
    line-height: 1.35;
  }

  /* ───── PART 3 — price = probability morph ───── */
  .eq-title-wrap {
    margin-top: 40px;
    position: relative;
    z-index: 1;
  }
  .eq-title-wrap .eyebrow,
  .eq-title-wrap .title {
    position: relative;
    z-index: 2;
  }
  .trade-chart-bg {
    position: absolute;
    right: 42px;
    top: 74px;
    width: 760px;
    height: 178px;
    overflow: visible;
    opacity: 0;
    pointer-events: none;
    z-index: 1;
  }
  .trade-chart-grid {
    stroke: var(--rule);
    stroke-width: 1;
  }
  .trade-chart-fill {
    fill: var(--gold);
    opacity: 0;
    transition: opacity 600ms ease;
  }
  .trade-chart-line {
    fill: none;
    stroke: var(--gold);
    stroke-width: 5;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-dasharray: 1400;
    stroke-dashoffset: 1400;
    opacity: 0;
  }
  .trade-chart-axis {
    stroke: var(--ink-mute);
    stroke-width: 1;
    opacity: 0.45;
  }
  .trade-chart-tick {
    fill: var(--ink-mute);
    font-family: var(--f-mono);
    font-size: 16px;
    letter-spacing: 0.08em;
    opacity: 0;
  }
  #slide-equation[data-deck-active] .trade-chart-bg {
    animation: chart-presence 5600ms ease forwards;
  }
  #slide-equation[data-deck-active] .trade-chart-fill {
    animation: chart-fill-in 900ms ease forwards 1500ms;
  }
  #slide-equation[data-deck-active] .trade-chart-line {
    animation: chart-line-draw 2400ms cubic-bezier(.2,.8,.2,1) forwards 500ms;
  }
  #slide-equation[data-deck-active] .trade-chart-tick {
    animation: chart-label-in 600ms ease forwards 1700ms;
  }
  @keyframes chart-line-draw {
    0%   { stroke-dashoffset: 1400; opacity: 0; }
    10%  { opacity: 1; }
    100% { stroke-dashoffset: 0; opacity: 1; }
  }
  @keyframes chart-presence {
    0%   { opacity: 0; }
    8%   { opacity: 0.34; }
    88%  { opacity: 0.34; }
    100% { opacity: 0; }
  }
  @keyframes chart-fill-in {
    to { opacity: 0.10; }
  }
  @keyframes chart-label-in {
    to { opacity: 0.7; }
  }
  .equation-stage {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 60px;
    margin-top: 80px;
    width: 100%;
    min-height: 420px;
  }
  .eq-term {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    min-width: 420px;
  }
  .eq-label {
    font-family: var(--f-mono);
    font-size: 26px;
    letter-spacing: 0.2em;
    color: var(--ink-mute);
    text-transform: uppercase;
  }
  .eq-value {
    font-size: 132px;
    font-weight: 600;
    letter-spacing: -0.04em;
    font-family: var(--f-mono);
    color: var(--ink);
    line-height: 1;
  }
  .eq-value.morph { color: var(--gold); }
  .eq-op { font-size: 100px; color: var(--ink-mute); font-weight: 300; }
  .eq-caption {
    margin-top: 60px;
    font-size: 30px;
    color: var(--ink-dim);
    font-family: var(--f-mono);
    text-align: center;
  }
  .eq-caption b { color: var(--gold); font-weight: 600; }

  /* morph transitions keyed by slide class */
  .eq-price, .eq-prob {
    transition: opacity 600ms ease, color 600ms ease;
  }

  /* ───── PART 4 — shadows ───── */
  .collapse-word {
    position: relative;
    display: inline-block;
    vertical-align: baseline;
    color: transparent;
    isolation: isolate;
  }
  .collapse-word-base {
    visibility: hidden;
  }
  .collapse-piece {
    position: absolute;
    inset: 0;
    color: var(--ink);
    will-change: transform, opacity;
  }
  .collapse-piece.top {
    clip-path: polygon(0 0, 100% 0, 100% 72%, 0 42%);
    transform-origin: 64% 70%;
  }
  .collapse-piece.bottom {
    clip-path: polygon(0 42%, 100% 72%, 100% 100%, 0 100%);
  }
  .collapse-word::after {
    content: "";
    position: absolute;
    inset: 0;
    background: var(--crimson);
    clip-path: polygon(0 41%, 100% 71%, 100% 74%, 0 44%);
    opacity: 0;
    transform: scaleX(0);
    transform-origin: left center;
    z-index: 4;
  }
  #slide-shadows[data-deck-active] .collapse-word::after {
    animation: collapse-cut 950ms ease forwards 5000ms;
  }
  #slide-shadows[data-deck-active] .collapse-piece.top {
    animation: collapse-slide 1700ms cubic-bezier(.16,.82,.22,1) forwards 5500ms;
  }
  @keyframes collapse-cut {
    0%   { opacity: 0; transform: scaleX(0); }
    35%  { opacity: 0.95; transform: scaleX(1); }
    100% { opacity: 0; transform: scaleX(1); }
  }
  @keyframes collapse-slide {
    0%   { transform: translate(0, 0) rotate(0deg); opacity: 1; }
    42%  { transform: translate(18px, 8px) rotate(2deg); opacity: 1; }
    100% { transform: translate(88px, 42px) rotate(7deg); opacity: 0; }
  }
  .scene-grid {
    margin-top: 64px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    width: 100%;
  }
  .scene {
    border-top: 1px solid var(--rule);
    padding-top: 40px;
  }
  .scene .year {
    font-family: var(--f-mono);
    font-size: 26px;
    color: var(--gold);
    letter-spacing: 0.08em;
  }
  .scene .head {
    font-size: 52px;
    font-weight: 600;
    margin-top: 18px;
    letter-spacing: -0.02em;
    line-height: 1.1;
  }
  .scene .desc {
    margin-top: 28px;
    font-size: 26px;
    color: var(--ink-dim);
    line-height: 1.5;
  }
  .scene .desc b { color: var(--ink); font-weight: 500; }