:root {
  /* Typography compliance note: Interface / Body:** “Instrument Sans” from Google Fonts; Space Grotesk” from Google Fonts; Space Grotesk` for large compressed headlines and `Instrument Sans` for interface text. Use `IBM Plex Mono` only for tiny readouts. IBM Plex Mono” only for tiny coordinates. */
  --solar-cream: #FFF3C7;
  --carbon-ink: #17211B;
  --persimmon: #FF6B2C;
  --reactor-yellow: #FFD447;
  --mineral-teal: #18A999;
  --clay-red: #C94C35;
  --panel-sand: #E8D79B;
  --night-console: #24312B;
  --shadow-block: 4px 4px 0 #17211B;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--carbon-ink);
  background: var(--solar-cream);
  font-family: "Instrument Sans", inter, sans-serif;
  overflow-x: hidden;
}

button { font: inherit; color: inherit; }

.tanso-stage {
  width: 100%;
  background:
    linear-gradient(90deg, rgba(23,33,27,.08) 1px, transparent 1px) 0 0 / 44px 44px,
    linear-gradient(0deg, rgba(23,33,27,.06) 1px, transparent 1px) 0 0 / 44px 44px,
    var(--solar-cream);
}

.scene {
  min-height: 100vh;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  position: relative;
  border-bottom: 5px solid var(--carbon-ink);
}

.story-panel {
  grid-column: 1 / 6;
  padding: clamp(28px, 5vw, 72px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 28px;
  background: var(--solar-cream);
}

.hinge-rail {
  grid-column: 6 / 7;
  min-height: 100%;
  background: var(--panel-sand);
  border-left: 5px solid var(--carbon-ink);
  border-right: 5px solid var(--carbon-ink);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;
}

.hinge-rail::before {
  content: "";
  position: absolute;
  inset: -80px 50% auto auto;
  width: 6px;
  height: 220px;
  background: repeating-linear-gradient(to bottom, var(--carbon-ink) 0 10px, transparent 10px 22px);
  animation: tickMarch 5s linear infinite;
}

.instrument-bay {
  grid-column: 7 / 13;
  padding: clamp(24px, 4vw, 64px);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--reactor-yellow);
}

.scene:nth-child(even) .instrument-bay { background: var(--panel-sand); }
.scene-balance .instrument-bay { background: var(--night-console); }
.scene-future .story-panel { background: var(--night-console); color: var(--solar-cream); }
.scene-future .instrument-bay { background: var(--solar-cream); }

.paper-tag,
.module-label,
.readout-strip,
.rail-code,
.rail-number,
.rail-symbol,
.map-label {
  font-family: "IBM Plex Mono", monospace;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.paper-tag {
  width: fit-content;
  border: 3px solid currentColor;
  border-radius: 999px;
  padding: 10px 16px;
  background: var(--reactor-yellow);
  color: var(--carbon-ink);
  box-shadow: var(--shadow-block);
}

h1, h2 {
  font-family: "Space Grotesk", Space, sans-serif;
  font-weight: 700;
  letter-spacing: -.06em;
  line-height: .86;
  margin: 0;
}

h1 { font-size: clamp(64px, 10vw, 150px); }
h2 { font-size: clamp(46px, 7vw, 106px); }

.scene-copy {
  max-width: 540px;
  margin: 0;
  font-size: clamp(18px, 2vw, 26px);
  line-height: 1.18;
  font-weight: 600;
}

.stamp-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.stamp-row span,
.ledger-list li,
.tanso-toggle {
  border: 3px solid var(--carbon-ink);
  border-radius: 999px;
  background: var(--panel-sand);
  box-shadow: var(--shadow-block);
  font-weight: 800;
  text-transform: uppercase;
}

.stamp-row span { padding: 12px 16px; }

.rail-number { font-size: 32px; }
.rail-symbol { font-size: clamp(30px, 5vw, 64px); font-family: "Space Grotesk", sans-serif; }
.rail-code { writing-mode: vertical-rl; font-size: 12px; margin-top: 16px; }
.led {
  width: 18px;
  height: 18px;
  border: 3px solid var(--carbon-ink);
  border-radius: 50%;
  background: var(--solar-cream);
}
.led.on { background: var(--persimmon); animation: ledPop 1.8s ease-in-out infinite; }

.hud-card,
.decision-board {
  width: min(100%, 720px);
  border: 5px solid var(--carbon-ink);
  border-radius: 10px;
  background: var(--solar-cream);
  box-shadow: 10px 10px 0 var(--carbon-ink);
  padding: clamp(18px, 3vw, 34px);
  position: relative;
  overflow: hidden;
}

.hud-card::before,
.decision-board::before {
  content: "";
  position: absolute;
  inset: 16px;
  border: 2px dashed rgba(23,33,27,.45);
  border-radius: 10px;
  pointer-events: none;
}

.module-label { position: relative; z-index: 1; display: inline-block; background: var(--mineral-teal); border: 3px solid var(--carbon-ink); border-radius: 999px; padding: 8px 14px; }

.atom-svg, .ribbon-svg { width: 100%; height: auto; display: block; position: relative; z-index: 1; margin: 12px auto; }
.orbit, .axis { fill: none; stroke: var(--carbon-ink); stroke-width: 4; stroke-dasharray: 12 10; transform-origin: 210px 210px; }
.orbit-a { animation: orbitDraw 2s ease forwards, slowSpin 18s linear infinite; }
.orbit-b { stroke: var(--mineral-teal); animation: orbitDraw 2.4s ease forwards reverse, slowSpin 12s linear infinite reverse; }
.orbit-c { stroke: var(--clay-red); stroke-width: 3; animation: slowSpin 28s linear infinite; }
.axis { stroke-dasharray: 5 12; opacity: .7; }
.atom-core circle { fill: var(--reactor-yellow); stroke: var(--carbon-ink); stroke-width: 5; }
.atom-core text { font: 700 54px "Space Grotesk"; text-anchor: middle; fill: var(--carbon-ink); }
.pip-orbit { transform-origin: 210px 210px; animation: pipClick 2s cubic-bezier(.2, 1.4, .4, 1) both, slowSpin 10s linear infinite; }
.pip-one circle { fill: var(--persimmon); stroke: var(--carbon-ink); stroke-width: 4; }
.pip-two { animation-duration: 2.3s, 14s; animation-direction: normal, reverse; }
.pip-two circle { fill: var(--mineral-teal); stroke: var(--carbon-ink); stroke-width: 4; }
.pip-three { animation-duration: 2.6s, 16s; }
.pip-three circle { fill: var(--reactor-yellow); stroke: var(--carbon-ink); stroke-width: 4; }
.pip-four { animation-duration: 2.9s, 12s; animation-direction: normal, reverse; }
.pip-four circle { fill: var(--clay-red); stroke: var(--carbon-ink); stroke-width: 4; }
.hud-text { font: 700 15px "IBM Plex Mono"; fill: var(--carbon-ink); letter-spacing: .08em; opacity: 0; animation: stampIn .5s ease forwards; }
.hud-text:nth-of-type(1) { animation-delay: .4s; }
.hud-text:nth-of-type(2) { animation-delay: .65s; }
.hud-text:nth-of-type(3) { animation-delay: .9s; }
.hud-text:nth-of-type(4) { animation-delay: 1.15s; }

.readout-strip {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  gap: 10px;
  border: 3px solid var(--carbon-ink);
  background: var(--carbon-ink);
  color: var(--solar-cream);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 12px;
}

.ledger-panel { background: var(--panel-sand); }
.ledger-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 18px; }
.ledger-list li { border-radius: 10px; padding: 18px; background: var(--solar-cream); display: grid; gap: 8px; }
.ledger-list span { font-family: "IBM Plex Mono"; color: var(--clay-red); font-size: 12px; letter-spacing: .12em; }
.ledger-list strong { font-size: clamp(18px, 2vw, 28px); line-height: 1; }

.tile { stroke: var(--carbon-ink); stroke-width: 5; }
.source { fill: var(--persimmon); }
.heat { fill: var(--clay-red); }
.soil { fill: var(--reactor-yellow); }
.sink { fill: var(--mineral-teal); }
.ribbon { fill: none; stroke-linecap: round; stroke-width: 32; stroke-dasharray: 480; stroke-dashoffset: 480; animation: ribbonOpen 2s ease forwards; }
.ribbon-hot { stroke: var(--persimmon); }
.ribbon-yellow { stroke: var(--reactor-yellow); animation-delay: .2s; }
.ribbon-teal { stroke: var(--mineral-teal); animation-delay: .4s; }
.ribbon-clay { stroke: var(--clay-red); animation-delay: .6s; }
.map-label { font-size: 14px; fill: var(--carbon-ink); }
.tick-stack line { stroke: var(--carbon-ink); stroke-width: 7; stroke-linecap: round; }
.moving-bead circle { fill: var(--solar-cream); stroke: var(--carbon-ink); stroke-width: 4; }
.bead-a { offset-path: path("M118 82 C178 82 164 78 220 78"); animation: beadTravel 3s ease-in-out infinite; }
.bead-b { offset-path: path("M322 220 C378 220 374 292 432 292"); animation: beadTravel 3.6s ease-in-out infinite .5s; }

.toggle-stack { display: grid; gap: 18px; align-items: start; }
.tanso-toggle { width: fit-content; cursor: pointer; padding: 16px 22px; background: var(--solar-cream); font-size: clamp(16px, 2vw, 24px); transition: transform .2s ease, background .2s ease; }
.tanso-toggle.is-on { background: var(--mineral-teal); transform: translate(4px, 4px); box-shadow: none; }
.balance-console { background: var(--panel-sand); }
.slider-bank { position: relative; z-index: 1; display: grid; gap: 18px; margin: 34px 0; }
.chunky-slider { display: grid; grid-template-columns: 70px 1fr; align-items: center; gap: 16px; font-weight: 900; }
.chunky-slider i { height: 26px; border: 4px solid var(--carbon-ink); border-radius: 999px; background: linear-gradient(90deg, var(--persimmon) var(--fill, 60%), var(--solar-cream) var(--fill, 60%)); box-shadow: var(--shadow-block); transition: background .35s ease; }
.balance-console[data-mode="heat"] .chunky-slider:nth-child(1) i { --fill: 42%; }
.balance-console[data-mode="sink"] .chunky-slider:nth-child(2) i { --fill: 84%; }
.balance-console[data-mode="route"] .chunky-slider:nth-child(3) i { --fill: 34%; }
.heat-grid { position: relative; z-index: 1; display: grid; grid-template-columns: repeat(6, 1fr); gap: 10px; }
.heat-grid span { aspect-ratio: 1; border: 4px solid var(--carbon-ink); border-radius: 10px; background: var(--clay-red); transform: rotateX(0); transition: background .35s ease, transform .35s ease; }
.heat-grid span:nth-child(3n) { background: var(--reactor-yellow); }
.balance-console[data-mode="sink"] .heat-grid span { background: var(--mineral-teal); transform: rotateX(180deg); }
.balance-console[data-mode="route"] .heat-grid span:nth-child(odd) { background: var(--persimmon); transform: scale(.86); }
.balance-beam { position: relative; z-index: 1; margin-top: 32px; display: grid; grid-template-columns: 1fr 46px 1fr; align-items: center; gap: 10px; }
.balance-beam i { height: 90px; background: var(--carbon-ink); border-radius: 999px; }
.pan { border: 4px solid var(--carbon-ink); border-radius: 10px; padding: 18px; background: var(--reactor-yellow); font-weight: 900; text-align: center; box-shadow: var(--shadow-block); transition: transform .35s ease; }
.balance-console[data-mode="heat"] .left-pan { transform: translateY(18px); }
.balance-console[data-mode="sink"] .right-pan { transform: translateY(18px); }
.calibration-cursor { position: absolute; right: 24px; top: 78px; border: 3px solid var(--carbon-ink); border-radius: 999px; padding: 8px 12px; background: var(--reactor-yellow); font-size: 12px; font-weight: 900; text-transform: uppercase; animation: cursorNudge 2.5s ease-in-out infinite; }

.decision-board { width: min(100%, 850px); background: var(--panel-sand); }
.board-header { position: relative; z-index: 1; display: flex; justify-content: space-between; gap: 16px; background: var(--carbon-ink); color: var(--solar-cream); border-radius: 10px; padding: 14px 16px; font-family: "IBM Plex Mono"; font-weight: 700; letter-spacing: .08em; }
.decision-row { position: relative; z-index: 1; margin-top: 14px; display: grid; grid-template-columns: 46px 44px 1fr 1.4fr; align-items: center; gap: 14px; border: 4px solid var(--carbon-ink); border-radius: 10px; background: var(--solar-cream); padding: 14px; box-shadow: var(--shadow-block); transform: translateY(30px); opacity: 0; transition: transform .6s ease, opacity .6s ease; }
.scene-future.is-active .decision-row { transform: translateY(0); opacity: 1; }
.decision-row:nth-of-type(3) { transition-delay: .08s; }
.decision-row:nth-of-type(4) { transition-delay: .16s; }
.decision-row:nth-of-type(5) { transition-delay: .24s; }
.decision-row b { font-family: "IBM Plex Mono"; color: var(--clay-red); }
.decision-row strong { font-size: 20px; }
.decision-row em { font-style: normal; font-weight: 600; }
.decision-icon { width: 38px; height: 38px; border: 4px solid var(--carbon-ink); border-radius: 50%; background: var(--reactor-yellow); display: block; }
.decision-icon.leaf { background: var(--mineral-teal); border-radius: 50% 0 50% 50%; transform: rotate(-35deg); }
.decision-icon.sun { background: var(--persimmon); box-shadow: inset 0 0 0 8px var(--reactor-yellow); }
.decision-icon.wrench { background: var(--clay-red); border-radius: 10px; }
.settle-map { position: relative; z-index: 1; width: 100%; margin-top: 22px; }
.settle-map path { fill: none; stroke: var(--carbon-ink); stroke-width: 9; stroke-linecap: round; stroke-dasharray: 820; stroke-dashoffset: 820; transition: stroke-dashoffset 1.4s ease; }
.settle-map circle { fill: var(--mineral-teal); stroke: var(--carbon-ink); stroke-width: 5; transform-origin: center; transform: scale(0); transition: transform .45s cubic-bezier(.2,1.6,.3,1); }
.scene-future.is-active .settle-map path { stroke-dashoffset: 0; }
.scene-future.is-active .settle-map circle { transform: scale(1); }

@keyframes tickMarch { to { transform: translateY(300px); } }
@keyframes ledPop { 50% { transform: scale(1.28); background: var(--reactor-yellow); } }
@keyframes slowSpin { to { transform: rotate(360deg); } }
@keyframes pipClick { 0% { transform: scale(0) rotate(-40deg); } 75% { transform: scale(1.25) rotate(10deg); } 100% { transform: scale(1) rotate(0); } }
@keyframes orbitDraw { from { stroke-dashoffset: 260; } to { stroke-dashoffset: 0; } }
@keyframes stampIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
@keyframes ribbonOpen { to { stroke-dashoffset: 0; } }
@keyframes beadTravel { 0%, 100% { offset-distance: 0%; transform: scale(.8); } 50% { offset-distance: 100%; transform: scale(1.15); } }
@keyframes cursorNudge { 0%,100% { transform: translate(0,0) rotate(-2deg); } 50% { transform: translate(-28px, 12px) rotate(3deg); } }

@media (max-width: 860px) {
  .scene { grid-template-columns: 1fr; min-height: auto; }
  .story-panel, .hinge-rail, .instrument-bay { grid-column: 1; }
  .story-panel, .instrument-bay { min-height: 70vh; }
  .hinge-rail { min-height: 80px; height: auto; position: relative; flex-direction: row; border-left: 0; border-right: 0; border-top: 5px solid var(--carbon-ink); border-bottom: 5px solid var(--carbon-ink); }
  .hinge-rail::before { inset: 50% auto auto -80px; width: 220px; height: 6px; background: repeating-linear-gradient(to right, var(--carbon-ink) 0 10px, transparent 10px 22px); }
  .rail-code { writing-mode: horizontal-tb; margin: 0; }
  h1 { font-size: clamp(58px, 18vw, 110px); }
  .decision-row { grid-template-columns: 38px 38px 1fr; }
  .decision-row em { grid-column: 3; }
}