:root {
  color-scheme: dark;
  --ink: #ececec;
  --muted: #a3a3a3;
  --accent: #ebce42;
  --page: #080808;
  --mono: 'IBM Plex Mono', ui-monospace, Menlo, Consolas, monospace;
  --sans: Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  --halo: 0 0 4px #080808, 0 0 10px #080808, 0 0 16px #080808;
}
* {
  box-sizing: border-box;
}
html {
  background: var(--page);
  scrollbar-width: thin;
  scrollbar-color: #777 var(--page);
  scroll-snap-type: y proximity;
}
html:has(dialog[open]) {
  overflow: hidden;
}
body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 16px/1.6 var(--sans);
}
button,
a {
  -webkit-tap-highlight-color: transparent;
}
button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}
button:hover,
a:hover {
  color: var(--accent);
}
[aria-disabled='true'] {
  opacity: 0.25;
  cursor: default;
}
[aria-disabled='true']:hover {
  color: inherit;
}
a {
  color: inherit;
}
[hidden] {
  display: none !important;
}
/* A dark halo keeps the accent ring visible over any part of the scene. */
:is(button, a, summary):focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  box-shadow: 0 0 0 7px var(--page);
}
[tabindex='-1']:focus {
  outline: none;
}
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ── World layers ─────────────────────────────────────────────────────────── */
#world {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  touch-action: pan-y;
}
#world canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: pan-y;
}
#scroll-track {
  position: relative;
  height: 680vh;
  height: 680svh;
  pointer-events: none;
}
#scroll-track .snap {
  position: absolute;
  left: 0;
  width: 1px;
  height: 1px;
  scroll-snap-align: start;
}
.vignette {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(90deg, #080808e6 0, #080808b3 14%, transparent 24%),
    linear-gradient(270deg, #080808eb 0, #080808c7 27%, transparent 44%),
    linear-gradient(0deg, #080808cc, transparent 28%);
}
.world-loading {
  position: absolute;
  left: 50%;
  top: 45%;
  margin: 0;
  transform: translate(-50%, -50%);
  font: 12px var(--mono);
  letter-spacing: 0.08em;
  color: #9a9a9a;
}
.world-fallback {
  position: absolute;
  top: 25%;
  left: 50%;
  transform: translateX(-50%);
  width: min(400px, calc(100% - 32px));
  padding: 25px;
  background: #151515;
  border: 1px solid #666;
  font-size: 16px;
  z-index: 3;
}
.hotspots {
  position: fixed;
  inset: 0;
  z-index: 3;
  pointer-events: none;
}
.hotspot {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 3;
  pointer-events: auto;
  background: #101010;
  border: 1px solid #aaa;
  color: #fff;
  font: 12px var(--mono);
  padding: 7px 9px;
  box-shadow: 3px 3px #0008;
  white-space: nowrap;
}
.hotspot::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  height: 16px;
  width: 1px;
  background: #aaa;
}
.hotspot-item {
  font-size: 10px;
  letter-spacing: 0.05em;
  padding: 4px 6px;
}
.hotspot:hover,
.hotspot.selected {
  background: var(--node-color);
  border-color: var(--node-color);
  color: #050505;
}
.world-tooltip {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 12;
  pointer-events: none;
  background: #101010;
  border: 1px solid #555;
  color: #eee;
  font: 12px var(--mono);
  padding: 4px 8px;
  white-space: nowrap;
}

/* ── Chrome around the world ──────────────────────────────────────────────── */
.skip-link {
  position: fixed;
  top: -100px;
  left: 20px;
  z-index: 30;
  background: #ddd;
  color: #111;
  padding: 10px;
}
.skip-link:focus {
  top: 15px;
}
.skip-link:focus-visible {
  box-shadow: none;
  outline-color: #111;
  outline-offset: -5px;
}
.identity {
  position: fixed;
  top: 35px;
  left: 36px;
  z-index: 6;
}
.identity button {
  text-align: left;
  padding: 0;
}
.logo {
  display: block;
  width: 86px;
  height: 53px;
  border: 4px solid #949494;
  color: #bbb;
  font: 600 40px/0.92 var(--mono);
  letter-spacing: -8px;
  padding: 3px 9px;
  position: relative;
}
.logo span {
  color: #999;
}
.logo i {
  position: absolute;
  width: 6px;
  height: 7px;
  right: 17px;
  bottom: 12px;
  background: #e8352e;
}
.logo i:nth-of-type(2) {
  left: 7px;
  top: 14px;
  background: #26a1d5;
}
.logo i:nth-of-type(3) {
  left: 21px;
  bottom: 2px;
  background: #f3d335;
}
.identity-name {
  display: block;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-top: 13px;
  text-shadow: var(--halo);
}
#chapter-nav {
  position: fixed;
  top: 50%;
  left: 0;
  transform: translateY(-38%);
  z-index: 5;
  display: grid;
  gap: 10px;
  padding: 14px 44px 14px 35px;
  background: linear-gradient(90deg, #080808f5 78%, #08080000);
}
#chapter-nav button {
  position: relative;
  font-size: 14px;
  text-align: left;
  font-weight: 600;
  padding: 3px 0;
  color: #a3a3a3;
  transition: color 0.3s;
  text-shadow: var(--halo);
}
#chapter-nav button span {
  display: inline-block;
  font: 11px var(--mono);
  width: 26px;
  color: #8c8c8c;
}
#chapter-nav button[aria-current='step'],
#chapter-nav button[aria-current='step'] span {
  color: #eee;
}
#chapter-nav button[aria-current='step']::before {
  content: '';
  width: 5px;
  height: 5px;
  background: var(--accent);
  position: absolute;
  left: -13px;
  top: 12px;
}
.utility {
  position: fixed;
  left: 35px;
  bottom: 35px;
  z-index: 5;
  display: grid;
  gap: 5px;
}
.utility button {
  font-size: 12px;
  text-align: left;
  color: #a3a3a3;
  padding: 2px 0;
  min-height: 24px;
  text-shadow: var(--halo);
}
.utility button:hover {
  color: #fff;
}
.utility .rotate {
  display: flex;
  gap: 10px;
}
.utility .rotate button {
  font-size: 17px;
  line-height: 1;
  min-width: 24px;
}
#menu-toggle {
  display: none;
  text-shadow: var(--halo);
}
.tour-controls {
  position: fixed;
  right: 35px;
  top: 35px;
  z-index: 6;
  display: flex;
  gap: 17px;
  align-items: center;
  background: #080808e6;
  padding: 6px 10px;
  margin: -6px -10px;
}
.tour-controls > span {
  font: 12px var(--mono);
  color: #b5b5b5;
  margin-right: 12px;
}
.tour-controls button {
  font-size: 24px;
  line-height: 1;
  padding: 4px;
  min-width: 32px;
}
.progress-line {
  position: fixed;
  right: 0;
  top: 0;
  height: 100%;
  width: 3px;
  background: #282828;
  z-index: 10;
}
.progress-line i {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--accent);
  transform-origin: top;
  transform: scaleY(0);
}

/* ── Chapter copy ─────────────────────────────────────────────────────────── */
#story {
  position: fixed;
  right: 5vw;
  bottom: 70px;
  width: min(380px, 31vw);
  z-index: 4;
  outline: none;
  pointer-events: none;
}
/* A soft scrim keeps the copy readable over bright equipment. */
#story::before {
  content: '';
  position: absolute;
  inset: -80px -60px -50px -90px;
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(closest-side, #080808eb 60%, #08080000);
}
#chapter-copy {
  pointer-events: auto;
}
.eyebrow {
  font: 12px var(--mono);
  letter-spacing: 0.11em;
  color: var(--accent);
  margin: 0 0 17px;
}
#story .eyebrow,
#story h1,
#story p.lead {
  text-shadow:
    0 0 2px #080808,
    0 0 8px #080808;
}
#story h1 {
  font-size: clamp(30px, 3vw, 48px);
  line-height: 1.05;
  letter-spacing: -0.055em;
  font-weight: 600;
  margin: 0 0 20px;
  text-wrap: balance;
}
#story p.lead {
  font-size: 16px;
  line-height: 1.65;
  color: #c9c9c9;
  margin: 0 0 22px;
  max-width: 350px;
}
.enter-button {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 35px;
  border-bottom: 1px solid #858585;
  padding: 13px 0;
  width: 100%;
  font-size: 14px;
}
.enter-button span {
  font-size: 22px;
}
.chapter-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin-top: 12px;
}
.chapter-actions :is(button, a) {
  font-size: 13px;
  border: 1px solid #777;
  background: #090909cc;
  padding: 9px 13px;
  text-decoration: none;
}
.chapter-actions [aria-pressed='true'] {
  border-color: var(--accent);
  color: var(--accent);
}
.chapter-actions :is(button, a):hover {
  border-color: #ddd;
}
.flow-caption {
  pointer-events: auto;
  font: 12px/1.65 var(--mono);
  color: #b8b8b8;
  margin: 14px 0 0;
  max-width: 360px;
  text-shadow:
    0 0 2px #080808,
    0 0 8px #080808;
}
.flow-caption:empty {
  display: none;
}

/* ── Drawers ──────────────────────────────────────────────────────────────── */
/* The equipment drawer is non-modal, so it sits above the chrome explicitly. */
dialog {
  position: fixed;
  inset: 0 0 0 auto;
  z-index: 20;
  margin: 0;
  width: min(460px, 100%);
  height: 100%;
  max-height: 100%;
  max-width: 100%;
  border: 0;
  border-left: 1px solid #454545;
  background: #101010;
  color: var(--ink);
  padding: 70px 35px 45px;
  overflow: auto;
  overscroll-behavior: contain;
}
dialog::backdrop {
  background: #0006;
}
body:has(#equipment-dialog[open]) :is(#story, #chapter-nav, #menu-toggle, .tour-controls) {
  visibility: hidden;
}
dialog .close-dialog {
  position: absolute;
  top: 21px;
  right: 26px;
  font-size: 30px;
  line-height: 1;
  min-width: 32px;
  min-height: 32px;
}
dialog h2 {
  font-size: 36px;
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.04em;
  margin: 0 0 22px;
}
dialog p {
  font-size: 16px;
  color: #bdbdbd;
}
dialog .eyebrow {
  font-size: 12px;
  color: var(--accent);
}
dialog a {
  color: #c3bc87;
  text-underline-offset: 3px;
}
.equipment-list {
  display: grid;
  margin: 18px 0 25px;
}
.equipment-list button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  padding: 15px 0;
  border-bottom: 1px solid #353535;
  font-size: 16px;
}
.equipment-list button span {
  color: var(--accent);
}
.equipment-path {
  font: 13px/1.8 var(--mono);
  border-top: 1px solid #414141;
  border-bottom: 1px solid #414141;
  padding: 20px 0;
  margin: 26px 0;
}
.back-equipment {
  font: 12px var(--mono);
  padding: 4px 0;
  margin-bottom: 23px;
  color: #a6a6a6;
}
.source-link {
  font: 12px var(--mono);
  display: inline-block;
  margin-top: 24px;
}
.detail-insight {
  font-size: 15px;
  line-height: 1.8;
}
.no-script {
  position: fixed;
  left: 24px;
  right: 24px;
  bottom: 24px;
  z-index: 8;
  max-width: 520px;
  margin: 0;
  padding: 20px;
  background: #151515;
  border: 1px solid #666;
}

/* ── Wide screens ─────────────────────────────────────────────────────────── */
@media (min-width: 1600px) {
  #story {
    right: 7vw;
    bottom: 12vh;
    width: 390px;
  }
  #story h1 {
    font-size: 53px;
  }
  .identity {
    left: 50px;
    top: 50px;
  }
  .utility {
    left: 50px;
  }
  #chapter-nav {
    padding-left: 50px;
  }
}

/* ── Small laptops ────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .identity {
    top: 25px;
    left: 24px;
  }
  .logo {
    width: 70px;
    height: 45px;
    font-size: 33px;
    padding: 3px 7px;
  }
  .identity-name {
    font-size: 16px;
  }
  #chapter-nav {
    padding-left: 25px;
    gap: 9px;
    top: 43%;
  }
  #chapter-nav button {
    font-size: 12px;
  }
  #chapter-nav button span {
    font-size: 10px;
    width: 22px;
  }
  .utility {
    left: 25px;
    bottom: 27px;
  }
  .tour-controls {
    top: 27px;
    right: 25px;
    gap: 14px;
  }
  .tour-controls > span {
    margin-right: 0;
  }
  #story {
    right: 30px;
    bottom: 66px;
    width: 300px;
  }
  #story h1 {
    font-size: 36px;
  }
  #story p.lead {
    font-size: 15px;
    line-height: 1.55;
  }
}

/* ── Stacked layout: phones and portrait tablets ──────────────────────────── */
@media (max-width: 700px), (orientation: portrait) and (max-width: 1100px) {
  .vignette {
    background:
      linear-gradient(0deg, #080808 0, #080808e6 30%, transparent 50%),
      linear-gradient(180deg, #080808b3 0, transparent 16%);
  }
  #story::before {
    display: none;
  }
  .identity {
    top: 21px;
    left: 21px;
  }
  .identity-name {
    font-size: 14px;
  }
  .tour-controls {
    right: 22px;
    top: 26px;
    gap: 11px;
  }
  .tour-controls > span {
    font-size: 11px;
  }
  #chapter-nav {
    display: none;
    top: 125px;
    left: 20px;
    right: 20px;
    transform: none;
    background: #0c0c0cf7;
    padding: 22px;
    border: 1px solid #555;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    z-index: 8;
  }
  #chapter-nav.open {
    display: grid;
  }
  #chapter-nav button {
    font-size: 14px;
  }
  #menu-toggle {
    display: block;
    position: fixed;
    top: 87px;
    right: 23px;
    z-index: 7;
    font: 12px var(--mono);
    padding: 4px 0;
    text-shadow: var(--halo);
  }
  #menu-toggle span {
    margin-left: 8px;
  }
  #story {
    left: 24px;
    right: 24px;
    bottom: 76px;
    width: auto;
    max-width: 440px;
  }
  #story h1 {
    font-size: 34px;
    margin-bottom: 13px;
    max-width: 340px;
  }
  #story p.lead {
    font-size: 14px;
    line-height: 1.55;
    margin-bottom: 13px;
    max-width: 380px;
  }
  .eyebrow {
    font-size: 11px;
    margin-bottom: 12px;
  }
  .enter-button {
    width: 270px;
    max-width: 100%;
    font-size: 13px;
    padding: 8px 0;
  }
  .utility {
    left: 23px;
    right: 23px;
    bottom: 22px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4px 16px;
  }
  .utility button {
    font-size: 11px;
  }
  .hotspot {
    font-size: 11px;
    padding: 6px;
  }
  .hotspot-item {
    font-size: 10px;
    padding: 4px 5px;
  }
  .flow-caption {
    font-size: 11px;
    line-height: 1.45;
    margin-top: 10px;
  }
  .chapter-actions button,
  .chapter-actions a {
    font-size: 12px;
    padding: 7px 10px;
  }
  .chapter-actions {
    margin-top: 7px;
  }
  .tour-controls button {
    font-size: 22px;
  }
  /* The equipment drawer becomes a bottom sheet so the 3D view stays visible above it. */
  #equipment-dialog {
    inset: auto 0 0 0;
    width: 100%;
    height: auto;
    max-height: 48svh;
    border-left: 0;
    border-top: 1px solid #454545;
    padding: 48px 24px 28px;
  }
  #equipment-dialog h2 {
    font-size: 28px;
    margin-bottom: 12px;
  }
  #equipment-dialog .close-dialog {
    top: 10px;
    right: 16px;
  }
  #about-dialog {
    padding: 70px 27px 35px;
  }
}

/* ── Short windows: collapse the chapter list and let the copy scroll ─────── */
@media (max-height: 560px) and (orientation: landscape) {
  .identity {
    top: 14px;
    left: 18px;
  }
  .logo {
    width: 58px;
    height: 37px;
    font-size: 27px;
    border-width: 3px;
    padding: 2px 6px;
    letter-spacing: -6px;
  }
  .identity-name {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
  }
  #chapter-nav {
    display: none;
    position: fixed;
    top: 60px;
    left: 18px;
    right: auto;
    transform: none;
    background: #0c0c0cf7;
    padding: 16px;
    border: 1px solid #555;
    grid-template-columns: 1fr 1fr;
    gap: 8px 18px;
    z-index: 8;
  }
  #chapter-nav.open {
    display: grid;
  }
  #menu-toggle {
    display: block;
    position: fixed;
    top: 22px;
    left: 92px;
    right: auto;
    z-index: 7;
    font: 12px var(--mono);
    padding: 4px 0;
  }
  #story {
    top: 64px;
    bottom: 44px;
    overflow: auto;
    overscroll-behavior: contain;
    pointer-events: auto;
  }
  #story::before {
    display: none;
  }
  #story h1 {
    font-size: 26px;
  }
}
/* Short stacked windows keep the copy at the bottom, scrolling if it would not fit. */
@media (max-height: 560px) and (orientation: portrait),
  (min-height: 501px) and (max-height: 560px) and (max-width: 700px) {
  #story {
    top: auto;
    bottom: 76px;
    max-height: calc(100% - 140px);
    overflow: auto;
    overscroll-behavior: contain;
    pointer-events: auto;
  }
}
@media (max-height: 500px) and (orientation: landscape) {
  .tour-controls {
    top: 14px;
    right: 18px;
  }
  #story {
    left: auto;
    right: 18px;
    top: 64px;
    bottom: 44px;
    width: min(360px, 46vw);
    max-width: none;
  }
  #story h1 {
    font-size: 24px;
    margin-bottom: 8px;
    max-width: none;
  }
  #story p.lead {
    font-size: 13px;
    line-height: 1.45;
    margin-bottom: 8px;
  }
  .eyebrow {
    font-size: 11px;
    margin-bottom: 6px;
  }
  .enter-button {
    padding: 6px 0;
    font-size: 13px;
    width: 100%;
  }
  .chapter-actions {
    margin-top: 4px;
  }
  .chapter-actions button,
  .chapter-actions a {
    font-size: 12px;
    padding: 6px 10px;
  }
  .flow-caption {
    margin-top: 6px;
    font-size: 11px;
  }
  .utility {
    left: 18px;
    right: auto;
    bottom: 8px;
    display: flex;
    gap: 14px;
  }
  .utility button {
    font-size: 11px;
  }
  .vignette {
    background: linear-gradient(270deg, #080808f0 0, #080808c0 38%, transparent 58%);
  }
  /* Landscape phones keep a side drawer; a bottom sheet would leave no room above it. */
  #equipment-dialog {
    inset: 0 0 0 auto;
    width: min(360px, 50vw);
    height: 100%;
    max-height: 100%;
    border-top: 0;
    border-left: 1px solid #454545;
    padding: 48px 22px 24px;
  }
}
@media (max-height: 300px) {
  .identity,
  .tour-controls > span {
    display: none;
  }
  #story {
    top: 48px;
    bottom: 32px;
  }
}
@media (max-width: 370px) {
  #story h1 {
    font-size: 29px;
  }
  #story p.lead {
    font-size: 13px;
  }
  .identity-name {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
  }
}
@media (max-width: 370px) and (orientation: portrait) {
  #menu-toggle {
    top: 77px;
  }
}

/* ── Past the journey (when the page continues after the track) ──────────── */
html:has(body.past-journey) {
  scroll-snap-type: none;
}
:is(.identity, #menu-toggle, #chapter-nav, .utility, #story, .tour-controls, .progress-line, .hotspots, .vignette) {
  transition:
    opacity 0.25s,
    visibility 0.25s;
}
body.past-journey
  :is(.identity, #menu-toggle, #chapter-nav, .utility, #story, .tour-controls, .progress-line, .hotspots) {
  opacity: 0;
  visibility: hidden;
}

/* ── User preferences ─────────────────────────────────────────────────────── */
@media (prefers-contrast: more) {
  :root {
    --muted: #c8c8c8;
  }
  #chapter-nav button,
  #chapter-nav button span,
  .utility button,
  #story p.lead {
    color: #d8d8d8;
  }
}
@media (forced-colors: active) {
  #chapter-nav button[aria-current='step'] {
    text-decoration: underline 2px;
    text-underline-offset: 4px;
  }
  #chapter-nav button[aria-current='step']::before,
  .progress-line i {
    forced-color-adjust: none;
    background: Highlight;
  }
}
@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}

/* ── Links to further material (set per chapter in content.js) ───────────── */
.chapter-links {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 16px;
}
.chapter-links .eyebrow {
  flex-basis: 100%;
  margin: 0 0 2px;
  font-size: 11px;
  color: #a6a6a6;
}
.chapter-links a {
  font-size: 13px;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: #777;
  text-shadow:
    0 0 2px #080808,
    0 0 8px #080808;
}