/* ─────────────────────────────────────────────────────────────
   Cellular Respiration — presentation design system
   Stage is a fixed 1920×1080 canvas scaled to fit any screen,
   so every size below is in "stage pixels".
   ───────────────────────────────────────────────────────────── */

@font-face {
  font-family: "Inter";
  src: url("../fonts/InterVariable.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg: #000;
  --surface: rgba(28, 28, 32, 0.78);
  --surface-2: rgba(255, 255, 255, 0.055);
  --surface-3: rgba(255, 255, 255, 0.09);
  --hairline: rgba(255, 255, 255, 0.12);
  --hairline-2: rgba(255, 255, 255, 0.2);
  --text: #f5f5f7;
  --text-2: #d2d2d7;
  --text-3: #98989f;
  --text-4: #6e6e73;

  /* molecules — one meaning per colour, used everywhere */
  --nadh: #30d158;
  --fadh: #ff6fae;
  --co2: #6aa8ff;
  --gtp: #ff9f0a;
  --atp: #ffd60a;
  --h: #ff453a;
  --e: #ffe45c;
  --o2: #64d2ff;
  --heat: #ff7a1a;

  /* enzymes */
  --e1: #ff6482;
  --e2: #bf8cff;
  --e3: #5ac8fa;
  --c1: #7d7aff;
  --c2: #d070ff;
  --c3: #2d9bff;
  --c4: #2ad4b4;
  --c5: #ffb340;

  --inhib: #ff453a;
  --activ: #30d158;

  --grad-0: linear-gradient(100deg, #7cc4ff 0%, #2f6bff 100%);
  --grad-1: linear-gradient(100deg, #64d2ff 0%, #30d158 100%);
  --grad-2: linear-gradient(100deg, #ffd60a 0%, #ff9f0a 50%, #ff6482 100%);
  --grad-3: linear-gradient(100deg, #d070ff 0%, #7d7aff 50%, #2d9bff 100%);
  --grad-atp: linear-gradient(100deg, #ffe45c 0%, #ff9f0a 100%);

  --ease: cubic-bezier(0.22, 0.75, 0.12, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --r-lg: 36px;
  --r-md: 24px;
  --r-sm: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", system-ui, sans-serif;
  font-feature-settings: "cv05" 1, "calt" 1;
  font-optical-sizing: auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body.idle, body.idle * { cursor: none !important; }

button { font: inherit; color: inherit; }
kbd {
  font: 600 0.8em/1 "Inter", sans-serif;
  padding: 0.18em 0.45em;
  border-radius: 0.35em;
  border: 1px solid var(--hairline-2);
  background: var(--surface-2);
}
sub, sup { font-size: 0.62em; line-height: 0; position: relative; }
sub { bottom: -0.28em; vertical-align: baseline; }
sup { top: -0.55em; vertical-align: baseline; }

/* ── stage ───────────────────────────────────────────── */
#viewport { position: fixed; inset: 0; overflow: hidden; background: var(--bg); }
#stage {
  position: absolute;
  left: 50%; top: 50%;
  width: 1920px; height: 1080px;
  transform-origin: 50% 50%;
  overflow: hidden;
  background: radial-gradient(1400px 900px at 70% 40%, #0b0d14 0%, #000 70%);
}
#gl {
  position: absolute; inset: 0;
  width: 1920px; height: 1080px;
  opacity: 0;
  transition: opacity 0.7s var(--ease);
  touch-action: none;
}
#gl.on { opacity: 1; }
#labels { position: absolute; inset: 0; pointer-events: none; }
#labels > div { pointer-events: none; }
#slides { position: absolute; inset: 0; pointer-events: none; }

/* ── slides ──────────────────────────────────────────── */
.slide {
  position: absolute; inset: 0;
  padding: 92px 120px 96px;
  display: flex; flex-direction: column;
  opacity: 0; visibility: hidden;
  transform: scale(1.012);
  transition: opacity 0.6s var(--ease), transform 0.9s var(--ease), visibility 0s linear 0.6s;
  pointer-events: none;
}
.slide.active {
  opacity: 1; visibility: visible; transform: none;
  transition: opacity 0.75s var(--ease) 0.12s, transform 1.1s var(--ease) 0.08s, visibility 0s;
}
.slide.active .widget, .slide.active [data-tip], .slide.active button,
.slide.active [data-goto], .slide.active .seg, .slide.active input,
.slide.active .chip, .slide.active a { pointer-events: auto; }

/* staggered reveal on slide entry */
.slide .rv {
  opacity: 0; transform: translateY(26px); filter: blur(10px);
  transition: opacity 0.8s var(--ease), transform 1s var(--ease), filter 0.8s var(--ease);
}
.slide.active .rv {
  opacity: 1; transform: none; filter: blur(0);
  transition-delay: calc(0.18s + var(--i, 0) * 0.08s);
}
/* step builds */
.slide [data-build] {
  opacity: 0; transform: translateY(22px); filter: blur(8px);
  transition: opacity 0.7s var(--ease), transform 0.9s var(--ease), filter 0.7s var(--ease), color 0.4s;
}
.slide [data-build].in { opacity: 1; transform: none; filter: blur(0); }
.slide [data-build].in.past { color: var(--text-3); }
.slide .bullets li.in.past b { color: var(--text-2); }

/* ── typography ─────────────────────────────────────── */
.eyebrow {
  margin: 0 0 18px;
  font-size: 30px; font-weight: 600; letter-spacing: 0.005em;
  color: var(--text-3);
}
h1, h2, h3 { margin: 0; font-weight: 700; letter-spacing: -0.028em; }
h2 { font-size: 86px; line-height: 1.02; }
h3 { font-size: 40px; letter-spacing: -0.02em; }
b, strong { font-weight: 650; color: #fff; }
i { font-style: italic; }
.dim { color: var(--text-3); }

.grad-0, .grad-1, .grad-2, .grad-3, .grad-atp {
  background-clip: text; -webkit-background-clip: text;
  color: transparent; -webkit-text-fill-color: transparent;
}
.grad-0 { background-image: var(--grad-0); }
.grad-1 { background-image: var(--grad-1); }
.grad-2 { background-image: var(--grad-2); }
.grad-3 { background-image: var(--grad-3); }
.grad-atp { background-image: var(--grad-atp); }
.eyebrow.grad-0, .eyebrow.grad-1, .eyebrow.grad-2, .eyebrow.grad-3 { display: inline-block; }

.t-nadh { color: var(--nadh); font-weight: 650; }
.t-fadh { color: var(--fadh); font-weight: 650; }
.t-co2 { color: var(--co2); font-weight: 650; }
.t-atp { color: var(--atp); font-weight: 650; }
.t-gtp { color: var(--gtp); font-weight: 650; }
.t-h { color: var(--h); font-weight: 650; }
.t-heat { color: #ffb37a; }
.t-heat b { color: var(--heat); }

.head { margin-bottom: 44px; }
.head.row { display: flex; align-items: flex-end; justify-content: space-between; gap: 40px; }
.head-note { margin: 0 0 10px; font-size: 28px; color: var(--text-3); display: flex; align-items: center; gap: 14px; }
.swatch { display: inline-block; width: 22px; height: 22px; border-radius: 6px; }
.swatch.red { background: rgba(255, 69, 58, 0.55); box-shadow: inset 0 0 0 2px #ff453a; }

.bullets { list-style: none; margin: 46px 0 0; padding: 0; }
.bullets li {
  position: relative;
  font-size: 44px; line-height: 1.22; font-weight: 500;
  color: var(--text);
  padding-left: 46px; margin-bottom: 30px;
  letter-spacing: -0.012em;
}
.bullets li::before {
  content: ""; position: absolute; left: 4px; top: 0.5em;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--text-4);
  transition: background 0.4s, box-shadow 0.4s;
}
.s0 .bullets li.in:not(.past)::before { background: #3d8bff; box-shadow: 0 0 18px #3d8bffaa; }
.s1 .bullets li.in:not(.past)::before { background: #30d158; box-shadow: 0 0 18px #30d15899; }
.s2 .bullets li.in:not(.past)::before { background: #ff9f0a; box-shadow: 0 0 18px #ff9f0a99; }
.s3 .bullets li.in:not(.past)::before { background: #7d7aff; box-shadow: 0 0 18px #7d7aff99; }
.bullets.small li { font-size: 38px; margin-bottom: 24px; }
.bullets li[data-tip], .eyebrow[data-tip] { cursor: help; }
.bullets li[data-tip] b, .bullets li[data-tip]:not(:has(b)) {
  text-decoration: underline dotted rgba(255, 255, 255, 0.38);
  text-decoration-thickness: 2px; text-underline-offset: 9px;
}

/* ── layouts ─────────────────────────────────────────── */
.layout-split { flex-direction: row; align-items: center; }
.layout-split .col-text { width: 760px; flex: none; position: relative; z-index: 2; }
.layout-split .col-text.narrow { width: 640px; }
.layout-split.wide-visual .col-text { width: 640px; }
.layout-split .col-visual { flex: 1; height: 100%; margin-left: 40px; position: relative; }

.layout-hero { justify-content: center; }
.hero { max-width: 1000px; }
.hero-title {
  font-size: 176px; line-height: 0.94; letter-spacing: -0.045em; font-weight: 750;
  background: linear-gradient(180deg, #fff 30%, #a9a9b2 100%);
  -webkit-background-clip: text; background-clip: text;
  color: transparent; -webkit-text-fill-color: transparent;
  padding-bottom: 8px;
}
.hero-sub { font-size: 50px; font-weight: 600; letter-spacing: -0.02em; margin: 34px 0 44px; color: var(--text-2); }
.tags { display: flex; gap: 14px; flex-wrap: wrap; }
.tags span {
  font-size: 26px; font-weight: 550; color: var(--text-2);
  padding: 12px 24px; border-radius: 999px;
  background: var(--surface-2); border: 1px solid var(--hairline);
}
.corner-hint, .scene-hint, .foot-hint {
  position: absolute; bottom: 52px; font-size: 24px; color: var(--text-4); margin: 0;
}
.corner-hint { left: 120px; }
.scene-hint { right: 120px; }
.foot-hint { left: 120px; }
.scene-hint[data-tip] { cursor: help; color: var(--text-3); }

.layout-divider { justify-content: center; }
.divider { max-width: 900px; }
.div-num { display: block; font-size: 200px; font-weight: 800; letter-spacing: -0.06em; line-height: 0.9; margin-bottom: 18px; }
.divider h1 { font-size: 150px; letter-spacing: -0.045em; line-height: 0.95; }
.divider p { font-size: 44px; color: var(--text-3); font-weight: 550; margin: 30px 0 0; letter-spacing: -0.015em; }

/* ── chips & controls ───────────────────────────────── */
.chips { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 40px; }
.chips.stack { flex-direction: column; align-items: flex-start; margin-top: 30px; gap: 12px; }
.chip {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 28px; font-weight: 600; padding: 12px 22px; border-radius: 999px;
  background: var(--surface-2); border: 1.5px solid var(--hairline);
  cursor: help; transition: background 0.3s, border-color 0.3s, transform 0.3s var(--ease);
}
.chip::before { content: ""; width: 16px; height: 16px; border-radius: 50%; background: currentColor; box-shadow: 0 0 14px currentColor; }
.chip:hover { transform: translateY(-2px); background: var(--surface-3); }
.chip.e1 { color: var(--e1); } .chip.e2 { color: var(--e2); } .chip.e3 { color: var(--e3); }
.chip.warm { color: #ffb37a; }

.seg {
  display: inline-flex; padding: 6px; gap: 4px; margin-top: 40px;
  border-radius: 999px; background: var(--surface-2); border: 1px solid var(--hairline);
}
.seg button {
  border: 0; background: transparent; cursor: pointer;
  font-size: 28px; font-weight: 600; color: var(--text-3);
  padding: 14px 30px; border-radius: 999px;
  transition: background 0.35s var(--ease), color 0.35s;
}
.seg button:hover { color: var(--text); }
.seg button.on { background: #fff; color: #000; }
.seg.danger button.on { background: #ff453a; color: #fff; }

.btn {
  display: inline-flex; align-items: center; gap: 14px;
  border: 0; cursor: pointer;
  font-size: 30px; font-weight: 650; letter-spacing: -0.01em;
  padding: 20px 38px; border-radius: 999px;
  background: #fff; color: #000;
  transition: transform 0.3s var(--ease), box-shadow 0.3s, background 0.3s;
}
.btn:hover { transform: translateY(-2px) scale(1.02); box-shadow: 0 16px 48px rgba(255, 255, 255, 0.18); }
.btn.ghost { background: var(--surface-2); color: var(--text); border: 1.5px solid var(--hairline-2); }
.btn.ghost:hover { background: var(--surface-3); box-shadow: none; }

/* ── roadmap ────────────────────────────────────────── */
.chapters { display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; flex: 1; max-height: 640px; }
.chapter {
  position: relative; border-radius: var(--r-lg); padding: 48px;
  background: linear-gradient(180deg, rgba(255,255,255,0.07), rgba(255,255,255,0.02));
  border: 1px solid var(--hairline);
  display: flex; flex-direction: column; justify-content: flex-end;
  cursor: pointer; overflow: hidden;
  transition: transform 0.6s var(--ease), border-color 0.4s, background 0.4s;
}
.chapter:hover { transform: translateY(-8px); border-color: var(--hairline-2); }
.chapter .ch-num { position: absolute; top: 40px; left: 48px; font-size: 34px; font-weight: 700; color: var(--text-4); }
.chapter .ch-tag { position: absolute; top: 44px; right: 48px; font-size: 24px; font-weight: 600; color: var(--text-3); padding: 6px 16px; border: 1px solid var(--hairline); border-radius: 999px; }
.chapter h3 { font-size: 58px; letter-spacing: -0.03em; }
.chapter p { font-size: 32px; color: var(--text-3); margin: 14px 0 0; font-weight: 500; }
.chapter .ch-icon { position: absolute; inset: 90px 40px 200px; display: grid; place-items: center; }
.chapter .ch-icon svg { width: 100%; height: 100%; overflow: visible; }
.chapter.c0 h3 { background: var(--grad-0); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }
.chapters.four { grid-template-columns: repeat(4, 1fr); gap: 28px; }
.chapters.four .chapter { padding: 40px 38px; }
.chapters.four .chapter h3 { font-size: 50px; }
.chapters.four .chapter p { font-size: 28px; }
.chapters.four .ch-num { left: 38px; } .chapters.four .ch-tag { right: 38px; }
.chapter.c1 h3 { background: var(--grad-1); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }
.chapter.c2 h3 { background: var(--grad-2); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }
.chapter.c3 h3 { background: var(--grad-3); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }

/* ── generic widget host ────────────────────────────── */
.widget { position: relative; flex: 1; min-height: 0; }
.widget svg { display: block; overflow: visible; }
.svg-text { font-family: "Inter", sans-serif; }

/* ── ETC complex list ───────────────────────────────── */
.complex-list { list-style: none; padding: 0; margin: 40px 0 0; }
.complex-list li {
  display: flex; align-items: center; gap: 22px;
  font-size: 34px; font-weight: 550; margin-bottom: 20px; letter-spacing: -0.01em;
  cursor: help; padding: 8px 14px 8px 8px; border-radius: 22px;
  transition: background 0.3s, opacity 0.6s, transform 0.8s var(--ease), filter 0.6s;
}
.complex-list li:hover, .complex-list li.hl { background: var(--surface-3); }
.cx {
  display: inline-grid; place-items: center; flex: none;
  min-width: 74px; height: 58px; padding: 0 14px; border-radius: 16px;
  font-size: 28px; font-weight: 750; color: #000;
}
.cx.c1 { background: var(--c1); } .cx.c2 { background: var(--c2); }
.cx.c3 { background: var(--c3); } .cx.c4 { background: var(--c4); }
.cx.c5 { background: var(--c5); } .cx.cm { background: #e5e5ea; font-size: 22px; }

/* ── mnemonic title ─────────────────────────────────── */
.mnemonic { font-weight: 600; color: var(--text-3); }
.mnemonic b { font-weight: 800; color: #fff; }

/* ── references ─────────────────────────────────────── */
.refs { display: grid; grid-template-columns: 1.15fr 1fr 1fr; gap: 24px; }
.refs .ref:first-child { grid-row: span 2; }
.refs .ref:first-child p.dim { margin-top: 18px; line-height: 1.5; }
.ref {
  padding: 36px 40px; border-radius: var(--r-md);
  background: var(--surface-2); border: 1px solid var(--hairline);
}
.ref-k { font-size: 22px; font-weight: 650; color: var(--text-3); text-transform: uppercase; letter-spacing: 0.08em; }
.ref h3 { font-size: 36px; margin: 12px 0 10px; }
.ref p { font-size: 26px; margin: 6px 0 0; color: var(--text-2); line-height: 1.35; }
.ref p.dim { color: var(--text-3); }

/* ── tooltip / detail card ──────────────────────────── */
#tip {
  position: absolute; left: 0; top: 0; z-index: 50;
  width: 600px; padding: 32px 36px 30px;
  border-radius: 30px;
  background: rgba(22, 22, 26, 0.86);
  backdrop-filter: blur(30px) saturate(1.6);
  -webkit-backdrop-filter: blur(30px) saturate(1.6);
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.55), inset 0 1px 0 rgba(255,255,255,0.08);
  pointer-events: none;
  opacity: 0; transform: translateY(10px) scale(0.97);
  transform-origin: var(--ox, 0) var(--oy, 50%);
  transition: opacity 0.28s var(--ease), transform 0.4s var(--ease);
}
#tip.show { opacity: 1; transform: none; }
#tip .tk { display: flex; align-items: center; gap: 12px; font-size: 22px; font-weight: 650; letter-spacing: 0.06em; text-transform: uppercase; color: var(--tc, var(--text-3)); margin-bottom: 10px; }
#tip .tk::before { content: ""; width: 12px; height: 12px; border-radius: 50%; background: var(--tc, var(--text-3)); box-shadow: 0 0 12px var(--tc, transparent); }
#tip .tt { font-size: 38px; font-weight: 700; letter-spacing: -0.02em; line-height: 1.1; margin-bottom: 18px; }
#tip ul { margin: 0; padding: 0; list-style: none; }
#tip li { position: relative; font-size: 26px; line-height: 1.35; color: var(--text-2); padding-left: 26px; margin: 0 0 10px; }
#tip li::before { content: ""; position: absolute; left: 2px; top: 0.6em; width: 8px; height: 8px; border-radius: 50%; background: var(--text-4); }
#tip .rows { display: grid; grid-template-columns: auto 1fr; gap: 10px 22px; margin-top: 4px; }
#tip .rows dt { font-size: 24px; color: var(--text-3); font-weight: 550; }
#tip .rows dd { margin: 0; font-size: 26px; color: var(--text); font-weight: 550; }
#tip .tn { margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--hairline); font-size: 22px; color: var(--text-3); line-height: 1.4; }

/* ── chrome ─────────────────────────────────────────── */
#chrome { position: absolute; inset: 0; pointer-events: none; z-index: 40; }
.progress { position: absolute; left: 0; right: 0; bottom: 0; height: 4px; background: rgba(255,255,255,0.06); }
.progress .bar { display: block; height: 100%; width: 0; background: linear-gradient(90deg, #64d2ff, #ffd60a, #d070ff); transition: width 0.8s var(--ease); }
.counter {
  position: absolute; right: 48px; bottom: 30px;
  display: flex; gap: 16px; align-items: baseline;
  font-size: 22px; font-weight: 600; color: var(--text-4);
  font-feature-settings: "tnum" 1;
  transition: opacity 0.6s;
}
.counter .sec { color: var(--text-3); }
.nav { position: absolute; right: 36px; top: 50%; transform: translateY(-50%); display: flex; flex-direction: column; gap: 14px; opacity: 0; transition: opacity 0.5s; }
.nav button {
  pointer-events: auto; width: 64px; height: 64px; border-radius: 50%;
  border: 1px solid var(--hairline); background: rgba(30,30,34,0.7);
  font-size: 40px; line-height: 1; color: var(--text-2); cursor: pointer;
  backdrop-filter: blur(12px); transition: background 0.3s;
}
.nav button:hover { background: rgba(60,60,66,0.9); }
body.mouse .nav { opacity: 1; }
body.idle .counter { opacity: 0.35; }

#blackout { position: absolute; inset: 0; background: #000; z-index: 60; opacity: 0; pointer-events: none; transition: opacity 0.6s; }
#blackout.on { opacity: 1; pointer-events: auto; }

/* ── overlays ───────────────────────────────────────── */
.overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
  opacity: 0; visibility: hidden;
  transition: opacity 0.4s var(--ease), visibility 0s linear 0.4s;
}
.overlay.open { opacity: 1; visibility: visible; transition: opacity 0.4s var(--ease); }
.ov-inner { position: absolute; inset: 4vh 4vw; overflow: auto; }
.ov-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 2vh; }
.ov-head h3 { font-size: clamp(22px, 2vw, 40px); }
.ov-head span { color: var(--text-3); font-size: clamp(13px, 1vw, 18px); }
.ov-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(clamp(160px, 15vw, 290px), 1fr)); gap: 1.2vw; }
.ov-card {
  text-align: left; cursor: pointer; border: 1px solid var(--hairline);
  background: var(--surface-2); border-radius: 18px; padding: 1.1vw 1.2vw;
  min-height: clamp(80px, 8vw, 150px);
  display: flex; flex-direction: column; justify-content: space-between;
  transition: background 0.25s, border-color 0.25s, transform 0.3s var(--ease);
}
.ov-card:hover { background: var(--surface-3); transform: translateY(-3px); }
.ov-card.cur { border-color: #fff; }
.ov-card .n { font-size: clamp(11px, 0.85vw, 16px); color: var(--text-4); font-weight: 650; }
.ov-card .t { font-size: clamp(14px, 1.15vw, 22px); font-weight: 650; letter-spacing: -0.01em; }
.ov-card.sec0 { box-shadow: inset 4px 0 0 #3d8bff; }
.ov-card.sec1 { box-shadow: inset 4px 0 0 #30d158; }
.ov-card.sec2 { box-shadow: inset 4px 0 0 #ff9f0a; }
.ov-card.sec3 { box-shadow: inset 4px 0 0 #7d7aff; }

.help-card {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  width: min(560px, 90vw); padding: 36px 40px; border-radius: 28px;
  background: rgba(28,28,32,0.9); border: 1px solid var(--hairline);
}
.help-card h3 { font-size: 30px; margin-bottom: 20px; }
.help-card dl { display: grid; grid-template-columns: auto 1fr; gap: 12px 24px; margin: 0; font-size: 17px; }
.help-card dt { color: var(--text-2); }
.help-card dd { margin: 0; color: var(--text-3); }
.help-card p { color: var(--text-3); margin: 22px 0 0; font-size: 16px; }

#quiz-overlay iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; background: #000; }
.quiz-close {
  position: absolute; top: 18px; right: 18px; z-index: 2;
  width: 48px; height: 48px; border-radius: 50%; border: 1px solid var(--hairline);
  background: rgba(40,40,44,0.85); color: var(--text); font-size: 20px; cursor: pointer;
}

/* ── 3D labels (CSS2D) ──────────────────────────────── */
.lbl {
  font: 600 28px/1.1 "Inter", sans-serif; letter-spacing: -0.01em;
  color: var(--text); white-space: nowrap;
  padding: 8px 16px; border-radius: 999px;
  background: rgba(16, 16, 20, 0.62);
  border: 1px solid rgba(255,255,255,0.14);
  backdrop-filter: blur(8px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.lbl.plain { background: none; border: 0; backdrop-filter: none; padding: 0; text-shadow: 0 2px 14px #000; }
.lbl.big { font-size: 36px; font-weight: 700; }
.lbl.sm { font-size: 24px; }
.lbl.muted { color: var(--text-3); }
.lbl.hidden { opacity: 0 !important; }
.lbl .sub { display: block; font-size: 0.72em; color: var(--text-3); font-weight: 550; margin-top: 4px; }
.lbl .cnum { color: var(--text-3); font-weight: 600; margin-left: 8px; }
.lbl.focus { background: rgba(255,255,255,0.92); color: #000; border-color: #fff; }
.lbl.focus .cnum, .lbl.focus .sub { color: #555; }
.lbl.space { font-size: 30px; font-weight: 650; color: var(--text-3); background: none; border: 0; backdrop-filter: none; text-transform: none; letter-spacing: 0; }

@media (prefers-reduced-motion: reduce) {
  .slide, .slide .rv, .slide [data-build] { transition-duration: 0.01s !important; filter: none !important; }
}