@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700&family=Space+Grotesk:wght@400;500;600&display=swap");

:root {
  --bg: #07090d;
  --panel: rgba(13, 17, 24, 0.82);
  --ink: #f5f7fb;
  --muted: #8d95a3;
  --hairline: rgba(255, 255, 255, 0.13);
  --accent: #ff7a59;
  --accent-rgb: 255, 122, 89;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

html, body { margin: 0; min-height: 100%; background: var(--bg); color: var(--ink); }

body {
  font-family: "Noto Sans SC", system-ui, sans-serif;
  overflow: hidden;
  letter-spacing: 0.01em;
}

button, input { font: inherit; }
button { color: inherit; }

#universe { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 0; }

.grain {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.18;
  background-image:
    repeating-radial-gradient(circle at 20% 30%, rgba(255,255,255,.13) 0 1px, transparent 1px 4px),
    repeating-radial-gradient(circle at 80% 70%, rgba(255,255,255,.08) 0 1px, transparent 1px 5px);
  background-size: 7px 9px, 11px 13px;
  mix-blend-mode: overlay;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 50% 50%, rgba(var(--accent-rgb), 0.1), transparent 32%),
    linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
  background-size: auto, 80px 80px, 80px 80px;
  transition: background 900ms ease;
}

.topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 10;
  height: 94px;
  padding: 0 42px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  border-bottom: 1px solid var(--hairline);
  background: linear-gradient(to bottom, rgba(7,9,13,.82), rgba(7,9,13,.22));
  backdrop-filter: blur(18px);
}

.brand { display: inline-flex; align-items: center; gap: 13px; width: fit-content; color: inherit; text-decoration: none; }
.brand-mark { position: relative; display: block; width: 34px; height: 34px; }
.brand-mark i { position: absolute; border: 1px solid var(--ink); border-radius: 50%; inset: 8px 0; transform: rotate(32deg); }
.brand-mark i:nth-child(2) { transform: rotate(-32deg); }
.brand-mark i:nth-child(3) { inset: 14px; border: 0; background: var(--accent); transition: background .6s; }
.brand strong { display: block; font-size: 15px; font-weight: 600; letter-spacing: .13em; }
.brand small { display: block; margin-top: 2px; color: var(--muted); font: 10px/1 "Space Grotesk"; letter-spacing: .18em; }

.chapter { color: var(--muted); font-size: 11px; letter-spacing: .24em; text-transform: uppercase; }
.top-actions { justify-self: end; display: flex; align-items: center; gap: 10px; }
.quiet-button { height: 38px; padding: 0 14px; border: 1px solid var(--hairline); border-radius: 999px; background: rgba(255,255,255,.035); font-size: 11px; letter-spacing: .1em; cursor: pointer; transition: border .25s, background .25s, transform .25s; }
.quiet-button:hover { border-color: rgba(var(--accent-rgb), .65); background: rgba(var(--accent-rgb), .08); transform: translateY(-1px); }
.quiet-button span:last-child { margin-left: 6px; }
.sound-button { display: flex; align-items: center; gap: 8px; }
.sound-bars { display: flex; align-items: center; gap: 2px; height: 12px; }
.sound-bars i { display: block; width: 2px; height: 4px; background: var(--muted); transition: .3s; }
.sound-bars i:nth-child(2) { height: 9px; }
.sound-button[aria-pressed="true"] .sound-bars i { background: var(--accent); animation: sound 700ms ease-in-out infinite alternate; }
.sound-button[aria-pressed="true"] .sound-bars i:nth-child(2) { animation-delay: -240ms; }
.sound-button[aria-pressed="true"] .sound-bars i:nth-child(3) { animation-delay: -420ms; }
@keyframes sound { to { height: 12px; } }

.experience { position: relative; z-index: 2; height: 100svh; min-height: 620px; padding: 94px 30px 58px; overflow: visible; }

.story-copy { position: absolute; z-index: 4; left: 30px; top: 50%; width: min(28vw, 430px); max-width: 430px; transform: translateY(-54%); pointer-events: none; }
.story-copy .read-more { pointer-events: auto; }
.eyebrow { display: flex; align-items: center; gap: 10px; color: var(--accent); font-size: 11px; font-weight: 600; letter-spacing: .26em; text-transform: uppercase; transition: color .6s; }
.eyebrow::before { content: ""; width: 24px; height: 1px; background: currentColor; }
.story-copy h1 { margin: 20px 0 22px; font-size: clamp(48px, 5.4vw, 92px); font-weight: 300; line-height: .98; letter-spacing: -.055em; }
.summary { max-width: 370px; margin: 0; color: #afb5c0; font-size: clamp(14px, 1.05vw, 17px); font-weight: 300; line-height: 1.9; }
.read-more { margin-top: 34px; padding: 0; display: flex; align-items: center; gap: 14px; border: 0; background: none; font-size: 12px; letter-spacing: .16em; cursor: pointer; }
.read-more i { position: relative; display: block; width: 42px; height: 42px; border: 1px solid var(--hairline); border-radius: 50%; transition: .35s var(--ease); }
.read-more i::before, .read-more i::after { content: ""; position: absolute; left: 13px; top: 20px; width: 14px; height: 1px; background: var(--ink); }
.read-more i::after { width: 6px; transform: rotate(45deg); transform-origin: right; left: 21px; top: 18px; }
.read-more:hover i { transform: translateX(6px); background: var(--accent); border-color: var(--accent); }

.focus-stage { position: absolute; z-index: 1; inset: 94px 0 48px; width: 100%; min-height: 520px; display: grid; place-items: center; touch-action: none; overflow: visible; }
#physics3d { position: absolute; z-index: 0; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.focus-trigger { position: absolute; z-index: 2; inset: 0; width: 100%; height: 100%; border: 0; border-radius: 0; background: transparent; cursor: crosshair; outline: none; touch-action: none; user-select: none; transition: opacity .7s var(--ease), transform .9s var(--ease); }
.focus-trigger::before { display: none; }
.focus-ring { display: none; }
.ring-one { inset: 10%; animation: breathe 8s ease-in-out infinite; }
.ring-two { inset: 20%; border-style: dashed; animation: rotate 28s linear infinite; }
.ring-three { inset: 33%; border-color: rgba(var(--accent-rgb),.55); animation: breathe 5s ease-in-out infinite reverse; }
.focus-trigger:hover .ring-one { inset: 6%; border-color: rgba(var(--accent-rgb),.42); }
.focus-trigger:hover .ring-two { inset: 16%; }
.focus-core { position: absolute; right: 2%; bottom: 11%; display: grid; place-content: center; width: 74px; height: 74px; z-index: 2; border-radius: 50%; background: rgba(7,9,13,.54); text-align: center; pointer-events: none; backdrop-filter: blur(12px); }
.focus-core b { font: 500 clamp(20px, 2.1vw, 34px)/1 "Space Grotesk"; letter-spacing: -.03em; }
.focus-core small { margin-top: 8px; color: var(--muted); font-size: 10px; letter-spacing: .22em; }
.focus-prompt { position: absolute; left: 50%; bottom: 3%; transform: translateX(-50%); white-space: nowrap; color: var(--muted); font-size: 10px; letter-spacing: .18em; }
.focus-prompt i { display: inline-grid; place-items: center; margin-left: 8px; width: 20px; height: 20px; border: 1px solid var(--hairline); border-radius: 50%; font-style: normal; color: var(--accent); }
.ion-readout { position: absolute; z-index: 3; left: 50%; top: 5%; display: grid; gap: 5px; transform: translateX(-50%); white-space: nowrap; text-align: center; opacity: 0; pointer-events: none; transition: opacity .5s, transform .5s var(--ease); }
.ion-readout > span { color: #b9c0ca; font: 500 9px/1 "Space Grotesk"; letter-spacing: .18em; }
.ion-readout i { display: inline-block; width: 5px; height: 5px; margin-right: 5px; border-radius: 50%; background: #8cf5d2; box-shadow: 0 0 10px #8cf5d2; animation: blink 1.8s infinite; }
.ion-readout b { color: #8cf5d2; font-weight: 500; }
.ion-readout small { color: #626b78; font-size: 8px; letter-spacing: .14em; }
.show-human-visual .ion-readout { opacity: 1; transform: translateX(-50%) translateY(0); }
.show-human-visual .focus-trigger { cursor: grab; }
.human-manipulating .focus-trigger { cursor: grabbing; }
.human-manipulating .ion-readout small, .human-zooming .ion-readout small { color: #c5ccd4; }
.show-human-visual .focus-core { right: 2%; bottom: 11%; width: 72px; height: 72px; place-content: center; background: rgba(7,9,13,.62); backdrop-filter: blur(10px); }
.show-human-visual .focus-core b { font-size: 20px; }
.show-human-visual .focus-core small { margin-top: 4px; }
.show-human-visual .ring-three { opacity: .35; }
.human-manipulating .ring-one { border-color: rgba(140,245,210,.42); transform: scale(1.035); }
.element-focus .focus-trigger { cursor: zoom-in; }
.element-focus .ring-one { border-color: rgba(140,245,210,.26); }
.element-focus .ring-two { border-color: rgba(var(--accent-rgb),.32); animation-duration: 16s; }
.element-focus .focus-core { opacity: .72; }
.element-focus .ion-readout { opacity: 1; }
.element-dive-hint .focus-prompt { color: #f5f7fb; animation: diveHint .7s var(--ease); }
.element-atomizing .focus-stage { animation: atomizeStage .42s var(--ease) both; }
@keyframes diveHint { 40% { transform: translateX(-50%) translateY(-8px); color: #8cf5d2; } }
@keyframes atomizeStage { to { transform: scale(1.12); opacity: .15; filter: blur(8px); } }
.scene3d-active .ion-readout { opacity: 1; }
.scene3d-active .focus-trigger { cursor: grab; }
.focus-stage.is-rotating .focus-trigger { cursor: grabbing; }
.scene-route { position: absolute; z-index: 4; left: 50%; top: 2%; display: flex; align-items: center; justify-content: center; gap: 8px; transform: translateX(-50%); white-space: nowrap; pointer-events: none; }
.scene-route span { color: #59616d; font: 500 8px/1 "Space Grotesk", "Noto Sans SC"; letter-spacing: .1em; }
.scene-route span.active { color: #dce2e9; }
.scene-route i { color: #3f4651; font: 400 10px/1 "Space Grotesk"; font-style: normal; }
.scene-hover { position: absolute; z-index: 5; left: 50%; bottom: 9%; max-width: 86%; padding: 8px 13px; border: 0; border-radius: 999px; background: rgba(7,9,13,.68); color: #cbd2db; font-size: 9px; letter-spacing: .08em; text-align: center; pointer-events: none; opacity: 0; transform: translate(-50%, 8px); transition: opacity .25s, transform .35s var(--ease); backdrop-filter: blur(10px); }
.scene-hover.visible { opacity: 1; transform: translate(-50%, 0); }
.quantum-controls { position: absolute; z-index: 6; left: 50%; bottom: 1%; display: none; align-items: center; gap: 8px; transform: translateX(-50%); }
.quantum-controls.visible { display: flex; }
.quantum-controls > div { display: flex; gap: 4px; padding: 3px; border: 1px solid var(--hairline); border-radius: 999px; background: rgba(7,9,13,.82); backdrop-filter: blur(12px); }
.quantum-controls button { height: 32px; padding: 0 13px; border: 0; border-radius: 999px; background: transparent; color: var(--muted); font-size: 9px; letter-spacing: .08em; cursor: pointer; }
.quantum-controls button.active { background: rgba(140,245,210,.12); color: #e7ecef; }
.quantum-controls .quantum-action { border: 1px solid rgba(255,122,89,.34); background: rgba(255,122,89,.1); color: #f1d2c9; }
body[data-scene-stage="elements"] .ring-one, body[data-scene-stage="atom"] .ring-one, body[data-scene-stage="electron"] .ring-one { border-color: rgba(140,245,210,.28); }
body[data-scene-stage="nucleus"] .ring-two, body[data-scene-stage="proton"] .ring-two { border-color: rgba(255,95,116,.3); animation-duration: 14s; }
body[data-scene-stage="quantum"] .ring-one { border-color: rgba(140,245,210,.36); }
body[data-scene-stage="quantum"] .ring-two { border-color: rgba(255,196,104,.24); }
.orbit-label { position: absolute; color: rgba(255,255,255,.3); font: 9px/1 "Space Grotesk"; letter-spacing: .22em; text-transform: uppercase; pointer-events: none; }
.orbit-label::before { content: ""; display: inline-block; width: 18px; height: 1px; margin-right: 8px; vertical-align: middle; background: currentColor; }
.orbit-label-a { left: 6%; top: 30%; transform: rotate(-65deg); }
.orbit-label-b { right: 2%; bottom: 27%; transform: rotate(58deg); }
@keyframes breathe { 50% { transform: scale(1.04); opacity: .48; } }
@keyframes rotate { to { transform: rotate(360deg); } }

.element-explorer { position: fixed; z-index: 16; inset: 112px 5vw 68px; padding: 26px 30px 18px; display: grid; grid-template-rows: auto 1fr auto auto; gap: 18px; border: 1px solid rgba(255,255,255,.14); background: radial-gradient(circle at 50% 42%, rgba(255,122,89,.12), transparent 36%), rgba(7,9,13,.94); box-shadow: 0 30px 120px rgba(0,0,0,.65); backdrop-filter: blur(24px); opacity: 0; visibility: hidden; pointer-events: none; transform: scale(.96) translateY(18px); transition: opacity .5s, transform .7s var(--ease), visibility .7s; overflow: hidden; }
.element-explorer::before { content: ""; position: absolute; inset: 0; pointer-events: none; background: linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px); background-size: 56px 56px; mask-image: radial-gradient(circle at 50% 45%, #000, transparent 78%); }
.human-elements-open .element-explorer { opacity: 1; visibility: visible; pointer-events: auto; transform: scale(1) translateY(0); }
.human-elements-open .focus-trigger { opacity: .12; transform: scale(.86); pointer-events: none; }
.human-elements-open .story-copy, .human-elements-open .facts-panel, .human-elements-open .scale-rail { opacity: .12; filter: blur(3px); pointer-events: none; transition: opacity .5s, filter .5s; }
.element-explorer-head { position: relative; z-index: 1; display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; padding-bottom: 16px; border-bottom: 1px solid var(--hairline); }
.element-explorer-head span { color: var(--accent); font: 500 9px/1 "Space Grotesk"; letter-spacing: .22em; }
.element-explorer-head h2 { margin: 8px 0 3px; font-size: clamp(28px, 3vw, 46px); font-weight: 300; line-height: 1; letter-spacing: -.04em; }
.element-explorer-head p { margin: 0; color: var(--muted); font-size: 11px; }
.element-explorer-head > button { flex: 0 0 auto; width: 42px; height: 42px; border: 1px solid var(--hairline); border-radius: 50%; background: rgba(255,255,255,.03); font: 300 24px/1 "Space Grotesk"; cursor: pointer; transition: .3s; }
.element-explorer-head > button:hover { border-color: var(--accent); transform: rotate(90deg); }
.element-section { position: relative; z-index: 1; min-width: 0; }
.element-section-label { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-bottom: 10px; }
.element-section-label span { font-size: 10px; font-weight: 600; letter-spacing: .18em; }
.element-section-label small { color: #676f7b; font-size: 9px; letter-spacing: .08em; }
.major-section { min-height: 0; }
.major-elements { height: calc(100% - 26px); min-height: 150px; display: grid; grid-template-columns: repeat(11, minmax(66px, 1fr)); gap: 7px; }
.element-card { position: relative; min-width: 0; padding: 9px 8px 8px; display: flex; flex-direction: column; align-items: flex-start; border: 1px solid rgba(255,255,255,.12); background: linear-gradient(145deg, rgba(255,122,89,.13), rgba(255,255,255,.02)); overflow: hidden; cursor: pointer; transition: transform .35s var(--ease), border-color .3s, background .3s; animation: elementEnter .65s var(--ease) both; animation-delay: calc(var(--element-index) * 35ms); }
.element-card::after { content: ""; position: absolute; right: -20px; bottom: -26px; width: 70px; height: 70px; border-radius: 50%; background: radial-gradient(circle, rgba(255,122,89,.38), transparent 68%); opacity: .5; transition: .35s; }
.element-card:hover, .element-card:focus-visible { z-index: 2; border-color: var(--accent); background: rgba(255,122,89,.14); transform: translateY(-6px); outline: none; }
.element-card:hover::after { opacity: 1; transform: scale(1.35); }
.atomic-number { color: #737b87; font: 9px/1 "Space Grotesk"; }
.element-card strong { margin-top: 8px; font: 500 clamp(22px, 2.2vw, 34px)/1 "Space Grotesk"; letter-spacing: -.05em; }
.element-name { margin-top: 2px; color: #cbd0d8; font-size: 10px; }
.element-share { margin-top: auto; color: var(--accent); font: 500 10px/1 "Space Grotesk"; }
.element-card small { height: 0; margin-top: 0; color: #929aa7; font-size: 8px; line-height: 1.45; opacity: 0; transform: translateY(8px); transition: .3s; }
.element-card:hover small, .element-card:focus-visible small { height: 24px; margin-top: 6px; opacity: 1; transform: translateY(0); }
.trace-section { flex: 0 0 auto; }
.trace-elements { display: flex; flex-wrap: wrap; gap: 6px; }
.trace-chip { min-width: 50px; height: 42px; padding: 5px 8px; display: grid; grid-template-columns: auto auto; grid-template-rows: 1fr 1fr; align-items: center; column-gap: 6px; border: 1px solid rgba(140,245,210,.14); background: rgba(140,245,210,.035); cursor: pointer; transition: .3s var(--ease); animation: elementEnter .55s var(--ease) both; animation-delay: calc((var(--element-index) - 7) * 25ms); }
.trace-chip span { grid-row: 1 / 3; color: #626b77; font: 8px/1 "Space Grotesk"; }
.trace-chip strong { align-self: end; color: #dce3e5; font: 500 13px/1 "Space Grotesk"; }
.trace-chip small { align-self: start; color: #6e7782; font-size: 8px; }
.trace-chip:hover, .trace-chip:focus-visible { border-color: #8cf5d2; background: rgba(140,245,210,.1); transform: translateY(-3px); outline: none; }
.element-disclaimer { position: relative; z-index: 1; margin: 0; color: #59616d; font-size: 9px; line-height: 1.5; }
.element-selection { position: absolute; z-index: 5; inset: 0; display: flex; align-items: center; justify-content: center; gap: 18px; background: rgba(7,9,13,.9); opacity: 0; visibility: hidden; pointer-events: none; transition: opacity .3s; }
.element-selection::before { content: ""; position: absolute; width: 260px; height: 260px; border: 1px solid rgba(255,122,89,.2); border-radius: 50%; animation: selectionPulse 1s ease-out infinite; }
.element-selection > span { align-self: flex-start; margin-top: calc(50vh - 112px); color: #6e7682; font: 10px/1 "Space Grotesk"; }
.element-selection > strong { color: var(--accent); font: 500 clamp(70px, 10vw, 132px)/.8 "Space Grotesk"; text-shadow: 0 0 50px rgba(255,122,89,.38); }
.element-selection div { display: flex; flex-direction: column; gap: 7px; }
.element-selection b { font-size: 18px; font-weight: 500; }
.element-selection small { color: var(--muted); font-size: 10px; }
.element-is-selected .element-selection { opacity: 1; visibility: visible; }
@keyframes elementEnter { from { opacity: 0; transform: translateY(18px); } }
@keyframes selectionPulse { from { transform: scale(.4); opacity: .8; } to { transform: scale(1.6); opacity: 0; } }

.facts-panel { position: absolute; z-index: 4; right: 30px; top: 50%; width: min(30vw, 390px); max-width: 390px; transform: translateY(-52%); }
.facts-head { display: flex; align-items: center; justify-content: space-between; padding-bottom: 14px; border-bottom: 1px solid var(--hairline); color: var(--muted); font-size: 10px; letter-spacing: .18em; }
.live-dot { color: var(--accent); }
.live-dot::before { content: ""; display: inline-block; width: 5px; height: 5px; margin-right: 6px; border-radius: 50%; background: currentColor; box-shadow: 0 0 10px currentColor; animation: blink 1.8s infinite; }
@keyframes blink { 50% { opacity: .25; } }
.property-list { padding: 8px 0 18px; }
.property { position: relative; display: grid; grid-template-columns: 1fr auto; gap: 12px; padding: 15px 2px; border-bottom: 1px solid rgba(255,255,255,.075); overflow: hidden; }
.property::before { content: ""; position: absolute; inset: 0; transform: translateX(-102%); background: linear-gradient(90deg, rgba(var(--accent-rgb),.11), transparent); transition: transform .45s var(--ease); }
.property:hover::before { transform: translateX(0); }
.property span { position: relative; color: var(--muted); font-size: 11px; }
.property strong { position: relative; font: 500 12px/1.4 "Space Grotesk", "Noto Sans SC"; }
.field-observer[aria-hidden="true"] { display: none; }
.field-observer { display: grid; gap: 14px; padding-top: 6px; }
.field-observer header { display: flex; align-items: end; justify-content: space-between; gap: 14px; padding-bottom: 13px; border-bottom: 1px solid rgba(255,255,255,.11); }
.field-observer header span { color: #8cf5d2; font: 500 9px/1 "Space Grotesk"; letter-spacing: .18em; }
.field-observer header strong { font-size: 13px; font-weight: 500; }
.field-modes { display: flex; flex-wrap: wrap; gap: 0 15px; }
.field-modes button { padding: 7px 0 6px; border: 0; border-bottom: 1px solid transparent; background: none; color: #737c88; font-size: 10px; cursor: pointer; transition: color .25s, border-color .25s; }
.field-modes button:hover, .field-modes button.active { color: #e4ebe9; border-color: #8cf5d2; }
.field-observer > p { min-height: 42px; margin: 0; color: #9aa4af; font-size: 10px; font-weight: 300; line-height: 1.75; }
.field-probe { display: grid; grid-template-columns: 1fr 1fr; gap: 9px 18px; padding: 14px 0; border-top: 1px solid rgba(255,255,255,.09); border-bottom: 1px solid rgba(255,255,255,.09); }
.field-probe span { color: #69737f; font-size: 9px; }
.field-probe strong { display: block; margin-top: 5px; color: #dbe4e5; font: 500 12px/1 "Space Grotesk"; }
.field-observer > small { color: #65707b; font-size: 9px; line-height: 1.55; }
body[data-scene-stage="atom"] .property-list { padding-bottom: 7px; }
.electron-workbench[aria-hidden="true"] { display: none; }
.electron-workbench { display: grid; gap: 20px; padding-top: 2px; }
.electron-workbench header { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 7px 16px; padding-bottom: 18px; border-bottom: 1px solid rgba(255,255,255,.11); }
.electron-workbench header > span { color: #8cf5d2; font: 500 9px/1 "Space Grotesk"; letter-spacing: .18em; }
.electron-workbench header > strong { grid-row: 1 / 3; grid-column: 2; color: #edf4f2; font-size: 12px; font-weight: 500; }
.electron-workbench header > strong b { color: #8cf5d2; font: 500 28px/1 "Space Grotesk"; }
.electron-workbench header > small { color: #a2abb6; font-size: 10px; letter-spacing: .08em; }
.electron-workbench header > code { grid-column: 1 / -1; color: #697480; font: 400 10px/1.6 "Space Grotesk"; white-space: normal; }
.electron-questions { display: flex; flex-wrap: wrap; gap: 0 16px; }
.electron-questions button { position: relative; padding: 8px 0 7px; border: 0; border-bottom: 1px solid transparent; background: none; color: #737c88; font-size: 10px; cursor: pointer; transition: color .25s, border-color .25s; }
.electron-questions button:hover, .electron-questions button.active { color: #e4ebe9; border-color: #8cf5d2; }
.electron-answer { min-height: 108px; }
.electron-answer strong { display: block; color: #e8ecef; font-size: 13px; font-weight: 500; }
.electron-answer p { margin: 10px 0 0; color: #99a3ae; font-size: 11px; font-weight: 300; line-height: 1.85; }
.electron-experiments { display: grid; gap: 9px; padding-top: 17px; border-top: 1px solid rgba(255,255,255,.11); }
.electron-experiments > span { color: #626c79; font: 500 9px/1 "Space Grotesk"; letter-spacing: .18em; }
.electron-experiments > div { display: flex; flex-wrap: wrap; gap: 6px; }
.electron-experiments button { padding: 8px 10px; border: 0; border-radius: 999px; background: rgba(255,255,255,.045); color: #88929f; font-size: 9px; cursor: pointer; transition: color .25s, background .25s; }
.electron-experiments button:hover, .electron-experiments button.active { background: rgba(140,245,210,.12); color: #dff8ef; }
.electron-experiments small { color: #8cf5d2; font-size: 9px; }
body[data-scene-stage="electron"] .facts-head,
body[data-scene-stage="electron"] .property-list { display: none; }
.standard-model-workbench[aria-hidden="true"] { display: none; }
.standard-model-workbench { display: grid; gap: 15px; padding-top: 4px; }
.standard-model-workbench header { display: flex; align-items: end; justify-content: space-between; gap: 14px; padding-bottom: 13px; border-bottom: 1px solid rgba(255,255,255,.11); }
.standard-model-workbench header span { color: #d68cff; font: 500 9px/1 "Space Grotesk"; letter-spacing: .16em; }
.standard-model-workbench header strong { font-size: 13px; font-weight: 500; }
.sm-modes { display: flex; flex-wrap: wrap; gap: 0 14px; }
.sm-modes button { padding: 7px 0 6px; border: 0; border-bottom: 1px solid transparent; background: none; color: #747c88; font-size: 10px; cursor: pointer; transition: color .25s, border-color .25s; }
.sm-modes button:hover, .sm-modes button.active { color: #f0e8f8; border-color: #d68cff; }
.standard-model-workbench > p { min-height: 54px; margin: 0; color: #9ca4af; font-size: 10px; font-weight: 300; line-height: 1.8; }
.sm-action[aria-hidden="true"], .sm-particles[aria-hidden="true"] { display: none; }
.sm-action { display: grid; gap: 8px; padding: 13px 0; border-top: 1px solid rgba(255,255,255,.09); border-bottom: 1px solid rgba(255,255,255,.09); }
.sm-action button { width: fit-content; padding: 8px 12px; border: 0; border-radius: 999px; background: rgba(214,140,255,.12); color: #f0e4f7; font-size: 9px; cursor: pointer; }
.sm-action small, .standard-model-workbench > small { color: #69717d; font-size: 9px; line-height: 1.55; }
.sm-particles { display: flex; flex-wrap: wrap; gap: 6px; }
.sm-particles button { padding: 7px 10px; border: 0; border-radius: 999px; background: rgba(255,255,255,.045); color: #89929d; font-size: 9px; cursor: pointer; transition: background .25s, color .25s; }
.sm-particles button:hover, .sm-particles button.active { background: rgba(214,140,255,.13); color: #f1e8f6; }
body[data-scene-stage="proton"] .property-list { padding-bottom: 7px; }
.lab-button { width: 100%; min-height: 76px; padding: 14px 14px; display: grid; grid-template-columns: 42px 1fr auto; align-items: center; gap: 12px; border: 1px solid var(--hairline); background: rgba(255,255,255,.035); text-align: left; cursor: pointer; transition: .35s var(--ease); }
.lab-button:hover { border-color: rgba(var(--accent-rgb),.55); background: rgba(var(--accent-rgb),.075); transform: translateY(-2px); }
.lab-icon { position: relative; display: grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; background: rgba(var(--accent-rgb),.12); }
.lab-icon i { position: absolute; width: 4px; height: 4px; border-radius: 50%; background: var(--accent); }
.lab-icon i:nth-child(1) { transform: translate(-8px, 5px); }
.lab-icon i:nth-child(2) { transform: translate(7px, -7px); }
.lab-icon i:nth-child(3) { transform: translate(8px, 8px); }
.lab-button small, .lab-button strong { display: block; }
.lab-button small { color: var(--muted); font-size: 9px; letter-spacing: .16em; }
.lab-button strong { margin-top: 5px; font-size: 12px; font-weight: 500; }
.lab-button > b { font: 300 25px/1 "Space Grotesk"; }

.scale-rail { position: absolute; z-index: 4; inset: auto 42px 20px; display: grid; grid-template-columns: 80px 1fr 80px; align-items: end; gap: 18px; }
.scale-meta { display: flex; align-items: center; gap: 8px; font: 11px/1 "Space Grotesk"; color: var(--muted); }
.scale-meta i { width: 18px; height: 1px; background: var(--hairline); }
.scale-meta span:first-child { color: var(--ink); }
.scale-track { position: relative; height: 26px; display: flex; align-items: center; }
.scale-track::before { content: ""; position: absolute; left: 0; right: 0; top: 50%; height: 1px; background: var(--hairline); }
.scale-step { position: relative; flex: 1; height: 26px; border: 0; background: none; cursor: pointer; }
.scale-step::before { content: ""; position: absolute; left: 50%; top: 50%; width: 4px; height: 4px; border-radius: 50%; background: #555d6a; transform: translate(-50%,-50%); transition: .4s var(--ease); }
.scale-step::after { content: attr(data-title); position: absolute; left: 50%; bottom: 24px; transform: translate(-50%, 5px); color: var(--muted); font-size: 9px; white-space: nowrap; opacity: 0; transition: .25s; }
.scale-step:hover::after, .scale-step.active::after { opacity: 1; transform: translate(-50%,0); }
.scale-step.passed::before { background: rgba(var(--accent-rgb),.62); }
.scale-step.active::before { width: 10px; height: 10px; background: var(--accent); box-shadow: 0 0 18px var(--accent); }
.scale-caption { grid-column: 2; display: flex; justify-content: space-between; align-items: center; margin-top: -2px; color: #535a66; font-size: 9px; letter-spacing: .18em; }
.scale-caption strong { color: var(--muted); font: 400 9px/1 "Space Grotesk"; letter-spacing: .12em; }
.footer-line { position: fixed; z-index: 5; left: 42px; bottom: 22px; display: none; color: #555d6a; font: 9px/1 "Space Grotesk"; letter-spacing: .16em; }
.footer-line a { margin-left: 14px; color: #767f8d; text-decoration: none; }

.sheet { position: fixed; z-index: 30; background: rgba(11,14,20,.96); border: 1px solid var(--hairline); backdrop-filter: blur(28px); visibility: hidden; opacity: 0; transition: transform .7s var(--ease), opacity .4s, visibility .7s; }
.sheet.open { visibility: visible; opacity: 1; transform: translate(0,0); }
.sheet-close { position: absolute; z-index: 2; right: 26px; top: 24px; width: 44px; height: 44px; border: 1px solid var(--hairline); border-radius: 50%; background: rgba(255,255,255,.03); font: 300 24px/1 "Space Grotesk"; cursor: pointer; transition: .3s; }
.sheet-close:hover { transform: rotate(90deg); border-color: var(--accent); }
.scrim { position: fixed; inset: 0; z-index: 20; background: rgba(0,0,0,.58); backdrop-filter: blur(4px); opacity: 0; pointer-events: none; transition: .4s; }
.scrim.visible { opacity: 1; pointer-events: auto; }
.detail-sheet { right: 20px; top: 20px; bottom: 20px; width: min(560px, calc(100vw - 40px)); padding: 76px 60px 60px; transform: translateX(calc(100% + 40px)); display: flex; flex-direction: column; justify-content: center; }
.sheet-index { position: absolute; top: 34px; left: 42px; color: rgba(255,255,255,.12); font: 500 80px/1 "Space Grotesk"; }
.detail-content { position: relative; }
.detail-content h2 { margin: 24px 0; font-size: clamp(42px, 5vw, 74px); font-weight: 300; letter-spacing: -.05em; }
.detail-content > p { color: #b7bec9; font-size: 16px; font-weight: 300; line-height: 2; }
.detail-callout { margin-top: 40px; padding: 22px 0 0; display: flex; justify-content: space-between; border-top: 1px solid var(--hairline); }
.detail-callout span { color: var(--muted); font-size: 10px; letter-spacing: .16em; }
.detail-callout strong { font: 500 13px/1 "Space Grotesk", "Noto Sans SC"; }

.materials-sheet { inset: 20px; padding: 64px 54px 48px; transform: translateY(calc(100% + 40px)); overflow: auto; }
.materials-head { display: flex; align-items: end; justify-content: space-between; gap: 30px; }
.materials-head h2 { margin: 12px 0 0; font-size: clamp(38px, 5vw, 72px); font-weight: 300; letter-spacing: -.05em; }
.search-box { width: min(380px, 40vw); display: flex; align-items: center; gap: 12px; padding: 0 4px 12px; border-bottom: 1px solid var(--hairline); }
.search-box span { color: var(--accent); font-size: 22px; }
.search-box input { width: 100%; border: 0; outline: 0; background: transparent; color: var(--ink); font-size: 12px; }
.search-box input::placeholder { color: #59616e; }
.material-filters { margin: 34px 0 24px; display: flex; flex-wrap: wrap; gap: 8px; }
.filter-chip { padding: 8px 14px; border: 1px solid var(--hairline); border-radius: 999px; background: none; color: var(--muted); font-size: 10px; cursor: pointer; }
.filter-chip.active, .filter-chip:hover { color: var(--ink); border-color: var(--accent); background: rgba(var(--accent-rgb),.09); }
.material-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.material-card { position: relative; min-height: 270px; padding: 24px; display: flex; flex-direction: column; border: 1px solid var(--hairline); background: rgba(255,255,255,.025); overflow: hidden; transition: .35s var(--ease); }
.material-card::before { content: ""; position: absolute; right: -60px; top: -70px; width: 180px; height: 180px; border-radius: 50%; background: radial-gradient(circle, var(--card-accent), transparent 67%); opacity: .16; transition: .4s; }
.material-card:hover { transform: translateY(-5px); border-color: color-mix(in srgb, var(--card-accent), transparent 45%); }
.material-card:hover::before { opacity: .3; transform: scale(1.15); }
.material-number { color: #505864; font: 10px/1 "Space Grotesk"; }
.material-card h3 { margin: auto 0 2px; font-size: 31px; font-weight: 300; letter-spacing: -.04em; }
.material-formula { color: var(--card-accent); font: 500 12px/1 "Space Grotesk"; }
.material-description { min-height: 48px; margin: 16px 0; color: #9ea6b2; font-size: 11px; line-height: 1.7; }
.material-data { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; padding-top: 14px; border-top: 1px solid rgba(255,255,255,.08); }
.material-data span { color: #69717e; font-size: 9px; }
.material-data strong { display: block; margin-top: 3px; color: #dce0e6; font: 400 10px/1.4 "Space Grotesk", "Noto Sans SC"; }

.lab-sheet { left: 20px; right: 20px; bottom: 20px; height: min(600px, calc(100svh - 40px)); padding: 68px 54px 42px; transform: translateY(calc(100% + 40px)); display: grid; grid-template-columns: minmax(280px,.75fr) minmax(500px,1.5fr); gap: 5vw; }
.lab-copy { align-self: center; }
.lab-copy h2 { margin: 22px 0 20px; font-size: clamp(42px, 5vw, 70px); font-weight: 300; line-height: 1; letter-spacing: -.05em; }
.lab-copy > p { color: #aeb5c0; font-size: 13px; line-height: 1.85; }
.lab-control { margin-top: 44px; display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 12px; color: var(--muted); font-size: 10px; letter-spacing: .12em; }
.lab-control input { grid-column: 1 / -1; width: 100%; accent-color: var(--accent); }
.lab-control output { color: var(--accent); font: 500 12px/1 "Space Grotesk"; }
.lab-viewport { position: relative; min-height: 380px; border: 1px solid var(--hairline); background: radial-gradient(circle, rgba(var(--accent-rgb),.08), transparent 55%); overflow: hidden; }
#labCanvas { width: 100%; height: 100%; }
.lab-hint { position: absolute; left: 18px; bottom: 16px; color: #636b77; font-size: 9px; letter-spacing: .13em; pointer-events: none; }

body.transitioning .story-copy, body.transitioning .facts-panel { animation: contentShift .65s var(--ease); }
@keyframes contentShift { 0% { opacity: 1; transform: translateY(-2vh); } 45% { opacity: 0; transform: translateY(-4vh); } 55% { opacity: 0; transform: translateY(1vh); } 100% { opacity: 1; transform: translateY(-2vh); } }

@media (max-width: 980px) {
  .topbar { height: 78px; padding: 0 22px; grid-template-columns: 1fr auto; }
  .chapter { display: none; }
  .sound-button span:last-child { display: none; }
  .experience { min-height: 700px; padding: 78px 22px 58px; }
  .story-copy { left: 22px; width: min(30vw, 270px); transform: translateY(-56%); }
  .focus-stage { inset: 78px 0 48px; height: auto; min-height: 490px; }
  .focus-trigger { width: 100%; }
  .element-explorer { inset: 92px 22px 54px; }
  .major-elements { grid-template-columns: repeat(6, minmax(72px, 1fr)); overflow-y: auto; }
  .facts-panel { right: 22px; width: min(34vw, 320px); max-width: 320px; transform: translateY(-52%); }
  .facts-head { display: flex; }
  .property-list { display: block; padding: 8px 0 18px; }
  .property { padding: 10px; }
  .electron-workbench { display: grid; grid-template-columns: 1fr; gap: 14px; }
  .electron-workbench header, .electron-questions, .electron-answer, .electron-experiments { grid-column: 1; grid-row: auto; }
  .lab-button { align-self: center; }
  .scale-rail { inset: auto 22px 16px; }
  .materials-sheet { inset: 10px; padding: 60px 28px 30px; }
  .material-grid { grid-template-columns: repeat(2, 1fr); }
  .lab-sheet { inset: 10px; height: calc(100svh - 20px); grid-template-columns: 1fr; grid-template-rows: auto 1fr; padding: 64px 28px 28px; overflow: auto; }
  .lab-copy { align-self: start; }
}

@media (max-width: 640px) {
  body { overflow: auto; }
  .topbar { position: fixed; }
  .brand small, .sound-button { display: none; }
  .quiet-button { padding: 0 11px; }
  .experience { height: auto; min-height: 100svh; padding: 106px 18px 92px; display: flex; flex-direction: column; align-items: stretch; gap: 0; }
  .story-copy { position: relative; left: auto; top: auto; order: 1; width: auto; max-width: none; transform: none; text-align: left; }
  .story-copy h1 { font-size: 54px; }
  .summary { line-height: 1.75; }
  .read-more { margin-top: 20px; }
  .focus-stage { position: relative; inset: auto; order: 2; width: calc(100% + 36px); height: 52vh; min-height: 390px; margin-left: -18px; }
  .focus-trigger { width: 100%; }
  .scene-route { top: 0; max-width: 92vw; overflow: hidden; }
  .scene-route span { font-size: 7px; }
  .scene-hover { bottom: 12%; max-width: 92%; }
  .quantum-controls { bottom: -5%; width: min(94vw, 420px); flex-wrap: wrap; justify-content: center; }
  .show-human-visual .focus-core { right: 7%; bottom: 13%; width: 64px; height: 64px; }
  .element-explorer { inset: 78px 8px 8px; padding: 18px 14px 14px; gap: 14px; overflow-y: auto; }
  .element-explorer-head h2 { font-size: 32px; }
  .element-explorer-head p { font-size: 10px; }
  .element-section-label { align-items: flex-end; }
  .element-section-label small { max-width: 180px; text-align: right; }
  .major-elements { height: auto; min-height: 0; grid-template-columns: repeat(3, 1fr); overflow: visible; }
  .element-card { min-height: 104px; }
  .element-card strong { font-size: 28px; }
  .element-card small { display: none; }
  .trace-elements { gap: 5px; }
  .trace-chip { min-width: 47px; flex: 1 0 47px; }
  .element-selection > span { margin-top: 0; align-self: center; }
  .facts-panel { position: relative; right: auto; top: auto; order: 3; display: block; width: auto; max-width: none; margin-top: -2px; transform: none; }
  .property-list { grid-template-columns: 1fr 1fr; }
  .electron-workbench { display: grid; grid-template-columns: 1fr; padding-top: 18px; }
  .electron-workbench[aria-hidden="true"] { display: none; }
  .electron-workbench header, .electron-questions, .electron-answer, .electron-experiments { grid-column: 1; grid-row: auto; }
  .lab-button { margin-top: 12px; }
  .scale-rail { position: relative; order: 4; inset: auto; margin-top: 34px; grid-template-columns: 56px 1fr; }
  .scale-caption { grid-column: 2; }
  .orbit-label { display: none; }
  .detail-sheet { inset: 8px; width: auto; padding: 76px 28px 36px; }
  .materials-sheet { inset: 8px; padding: 64px 20px 24px; }
  .materials-head { display: block; }
  .search-box { width: 100%; margin-top: 28px; }
  .material-grid { grid-template-columns: 1fr; }
  .material-card { min-height: 230px; }
  .lab-sheet { inset: 8px; height: calc(100svh - 16px); padding: 64px 20px 22px; }
  .lab-copy h2 { font-size: 46px; }
  .lab-viewport { min-height: 310px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; scroll-behavior: auto !important; }
}