/* Lumina: museum captions around a glowing exhibit.
   Serif for names, the system sans for everything you operate. Ivory on black,
   hairlines, no decoration. The particles are the only thing that glows. */

:root {
  --ink: #000;
  --panel: #0d0c0b;
  --text: #ebe6dc;
  --muted: #9a948a;
  --faint: rgba(235, 230, 220, 0.5);
  --line: rgba(235, 230, 220, 0.18);
  --gutter: clamp(16px, 3vw, 36px);
  --serif: 'Newsreader', 'Iowan Old Style', 'Palatino Linotype', Georgia, serif;
  --sans: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  /* Keeps text legible where it crosses bright particles. */
  --lift: 0 0 2px #000, 0 0 8px #000, 0 0 16px rgba(0, 0, 0, 0.8);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: var(--ink);
  color: var(--text);
  font: 400 14px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
}

#scene {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
  touch-action: none;
}
#scene:active { cursor: grabbing; }

.caps { font-variant-caps: all-small-caps; letter-spacing: 0.04em; }

/* ── buttons: words, not pills ───────────────────────── */
button {
  font: 400 13px/1 var(--sans);
  color: var(--muted);
  background: none;
  border: 0;
  border-radius: 0;
  padding: 8px 0;
  cursor: pointer;
  text-decoration: underline 1px transparent;
  text-underline-offset: 5px;
  transition: color 0.15s, text-decoration-color 0.15s;
}
button:hover { color: var(--text); }
button[aria-pressed='true'], button[aria-expanded='true'] { color: var(--text); text-decoration-color: currentColor; }
button:focus-visible, a:focus-visible { outline: 1px solid var(--text); outline-offset: 4px; }
button.primary { color: var(--text); text-decoration-color: currentColor; }
a { color: inherit; text-underline-offset: 3px; text-decoration-thickness: 1px; }

/* ── top line ────────────────────────────────────────── */
.brand {
  position: fixed;
  top: var(--gutter);
  left: var(--gutter);
  right: var(--gutter);
  display: flex;
  align-items: baseline;
  gap: 16px;
  pointer-events: none;
}
.wordmark { font: italic 400 20px/1 var(--serif); }
.status { color: var(--muted); font-size: 13px; }

/* ── the catalogue entry ─────────────────────────────── */
.model {
  position: fixed;
  left: var(--gutter);
  bottom: calc(var(--gutter) + 48px);
  max-width: min(60ch, calc(100vw - 2 * var(--gutter)));
  pointer-events: none;
  text-shadow: var(--lift);
}
.model-number { margin: 0 0 6px; color: var(--muted); font-size: 12px; font-variant-caps: all-small-caps; letter-spacing: 0.06em; }
.model h1 {
  margin: 0;
  font: 400 44px/1.05 var(--serif);
  letter-spacing: -0.01em;
  transition: opacity 0.4s;
}
.model p { margin: 6px 0 0; color: var(--muted); font-size: 13px; }
.model .credit { margin-top: 2px; font-size: 12px; pointer-events: auto; }
.model .credit[hidden] { display: none; }
.model .credit a { color: var(--muted); }
.model .credit a:hover { color: var(--text); }
body[data-mode='dormant'] .model h1 { opacity: 0.45; }

.parts {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  pointer-events: auto;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.3s;
}
body[data-mode='formed'] .parts { opacity: 1; }
.parts li { display: flex; align-items: center; gap: 6px; cursor: default; color: var(--muted); }
.parts li span { color: var(--muted); }
.parts li:hover span, .parts li.active span { color: var(--text); text-decoration: underline 1px; text-underline-offset: 3px; }
.parts i { width: 6px; height: 6px; background: currentColor; }

body.compact .model h1 { font-size: 24px; }
body.compact .parts { display: none; }

/* ── part labels: placards ───────────────────────────── */
.leaders, .labels {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.leaders line { stroke-width: 1; stroke-opacity: 0.55; }
.label {
  position: absolute;
  top: 0;
  left: 0;
  display: block;
  max-width: 260px;
  padding: 2px 0;
  color: var(--text);
  text-align: left;
  text-shadow: var(--lift);
  pointer-events: auto;
  visibility: hidden;
  transition: none;
}
.label:hover { color: var(--text); }
.label-name {
  display: block;
  font: 400 16px/1.2 var(--serif);
  font-variant-caps: all-small-caps;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.label-name::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 8px;
  background: var(--part);
  vertical-align: 2px;
}
.label-info {
  display: none;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font: 400 13px/1.45 var(--sans);
}
.label.active { width: 240px; z-index: 1; }
.label.active .label-name { white-space: normal; }
.label.active .label-info { display: block; color: var(--text); }

.finger {
  position: fixed;
  top: -9px;
  left: -9px;
  width: 18px;
  height: 18px;
  border: 1px solid var(--text);
  border-radius: 50%;
  pointer-events: none;
}
.finger[hidden] { display: none; }

/* ── how far apart ───────────────────────────────────── */
.meter {
  position: fixed;
  top: calc(var(--gutter) + 30px);
  left: var(--gutter);
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 12px;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.06em;
}
.meter[hidden] { display: none; }
body.starting .model, body.starting .meter, body.starting .controls { visibility: hidden; }
.meter-track { width: 96px; height: 1px; background: var(--line); }
.meter-fill { height: 100%; width: 0; background: var(--text); }

/* ── camera preview ──────────────────────────────────── */
.cam {
  position: fixed;
  right: var(--gutter);
  bottom: calc(var(--gutter) + 48px);
  width: clamp(140px, 18vw, 240px);
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid var(--line);
  background: #000;
}
.cam video, .cam canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scaleX(-1);
}
.cam video { opacity: 0.4; filter: grayscale(1); }
.cam-pose {
  position: absolute;
  left: 10px;
  bottom: 6px;
  color: var(--text);
  font-size: 12px;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.06em;
  text-shadow: var(--lift);
}

/* ── controls: one line of words ─────────────────────── */
.controls {
  position: fixed;
  left: var(--gutter);
  right: var(--gutter);
  bottom: calc(var(--gutter) - 8px);
  display: flex;
  flex-wrap: wrap;
  gap: 0 22px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
}
.controls [data-action='help'] { margin-left: auto; }

/* ── model list: a catalogue index ───────────────────── */
.picker {
  position: fixed;
  left: var(--gutter);
  bottom: calc(var(--gutter) + 48px);
  width: min(300px, calc(100vw - 2 * var(--gutter)));
  max-height: min(70vh, 560px);
  overflow-y: auto;
  padding: 8px 16px 12px;
  border: 1px solid var(--line);
  background: var(--panel);
  z-index: 4;
}
.picker[hidden] { display: none; }
.picker-title {
  margin: 12px 0 4px;
  color: var(--muted);
  font-size: 12px;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.06em;
}
.picker button {
  display: flex;
  align-items: baseline;
  gap: 12px;
  width: 100%;
  padding: 7px 0;
  border-bottom: 1px solid var(--line);
  color: var(--text);
  text-align: left;
  text-decoration: none;
}
.picker button:hover .picker-name { text-decoration: underline 1px; text-underline-offset: 4px; }
.picker-num { width: 20px; flex: none; color: var(--muted); font: 400 11px/1 var(--sans); font-variant-numeric: tabular-nums; }
.picker-name { font: 400 17px/1.2 var(--serif); }
.picker button[aria-current='true'] .picker-name { text-decoration: underline 1px; text-underline-offset: 4px; }
.picker .picker-open { margin-top: 10px; border-bottom: 0; color: var(--muted); font: 400 13px/1 var(--sans); }
.picker .picker-open:hover { color: var(--text); }

/* ── first-run hint ──────────────────────────────────── */
.hint {
  position: fixed;
  top: calc(var(--gutter) + 60px);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: baseline;
  gap: 14px;
  max-width: calc(100vw - 2 * var(--gutter));
  color: var(--text);
  font: italic 400 17px/1.35 var(--serif);
  text-align: center;
  text-shadow: var(--lift);
}
.hint[hidden] { display: none; }
.hint button { flex: none; padding: 6px 8px; margin: -6px -8px; font-style: normal; font-size: 12px; }
body.starting .hint { display: none; }

/* ── gesture guide (camera on) ───────────────────────── */
.guide {
  position: fixed;
  top: calc(var(--gutter) + 60px);
  left: var(--gutter);
  width: 200px;
  pointer-events: none;
  text-shadow: var(--lift);
}
.guide[hidden] { display: none; }
.guide-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 6px;
}
.guide-head button { padding: 7px 8px; margin: -7px -8px; font-size: 11px; pointer-events: auto; }
.guide-title {
  color: var(--muted);
  font-size: 12px;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.06em;
}
.guide ul { margin: 0; padding: 0; list-style: none; }
.guide ul[hidden] { display: none; }
.guide li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 4px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  transition: color 0.2s;
}
.guide li b {
  width: 86px;
  flex: none;
  white-space: nowrap;
  font-weight: 400;
  font: 400 15px/1.2 var(--serif);
  font-variant-caps: all-small-caps;
  letter-spacing: 0.03em;
}
.guide li span { color: var(--muted); font-size: 12px; }
/* Gestures that do something now are ivory; the rest stay readable in grey. */
.guide li.now, .guide li.held { color: var(--text); }
.guide li.held b { text-decoration: underline 1px; text-underline-offset: 4px; }
.guide li.held span { color: var(--text); }
body.starting .guide { display: none; }

/* ── messages ────────────────────────────────────────── */
.toast {
  position: fixed;
  top: var(--gutter);
  left: 50%;
  transform: translateX(-50%);
  max-width: min(520px, calc(100vw - 2 * var(--gutter)));
  padding: 10px 14px;
  border-left: 1px solid var(--text);
  background: var(--panel);
  font-size: 13px;
  z-index: 6;
}

/* ── sheets: start, help, drop ───────────────────────── */
.sheet {
  position: fixed;
  inset: 0;
  display: grid;
  align-items: center;
  padding: var(--gutter);
  background: rgba(0, 0, 0, 0.82);
}
.sheet[hidden] { display: none; }

.start-body { max-width: 30rem; margin-left: clamp(0px, 8vw, 128px); }
.start h2 { margin: 0 0 16px; font: 400 clamp(36px, 5vw, 56px)/1.05 var(--serif); letter-spacing: -0.01em; }
.start p { margin: 0 0 28px; color: var(--muted); font-size: 15px; }
.start-actions { display: flex; flex-wrap: wrap; gap: 0 28px; margin-bottom: 20px; }
.start-actions button { font-size: 15px; padding: 10px 0; }
.start .fine { margin: 0; color: var(--muted); font-size: 12px; }

.help { background: var(--panel); overflow-y: auto; align-items: start; }
.help-body { max-width: 48rem; margin: 6vh auto 0; padding-bottom: 48px; }
.help h2 { margin: 0 0 28px; font: 400 36px/1.1 var(--serif); }
.help h3 { margin: 0 0 10px; font: 400 20px/1.2 var(--serif); }
.help-cols { display: grid; grid-template-columns: 1.2fr 1fr; gap: 48px; margin-bottom: 32px; }
.help dl { margin: 0; }
.help dl div { display: grid; grid-template-columns: 7rem 1fr; gap: 12px; padding: 7px 0; border-top: 1px solid var(--line); }
.help dt { font: 400 15px/1.3 var(--serif); font-variant-caps: all-small-caps; letter-spacing: 0.03em; }
.help dd { margin: 0; color: var(--muted); font-size: 13px; }
.help-own { margin-bottom: 28px; max-width: 40rem; }
.help-own p { margin: 0; color: var(--muted); }
.help-own strong { color: var(--text); font-weight: 500; }
kbd {
  font: 400 12px/1 var(--sans);
  padding: 1px 0;
  border-bottom: 1px solid var(--line);
}

.drop {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  padding: var(--gutter);
  background: rgba(0, 0, 0, 0.82);
  pointer-events: none;
  z-index: 5;
}
.drop[hidden] { display: none; }
.drop-body { width: min(520px, 100%); padding: 56px 32px; border: 1px dashed var(--faint); text-align: center; }
.drop-title { margin: 0 0 8px; font: 400 clamp(22px, 3vw, 30px)/1.2 var(--serif); }
.drop-fine { margin: 0; color: var(--muted); font-size: 13px; }

.noscript { position: fixed; inset: 0; display: grid; place-items: center; }

/* ── phones ──────────────────────────────────────────── */
@media (max-width: 719px) {
  /* One swipeable row of controls instead of a wrapped block. */
  .controls { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; gap: 0 20px; }
  .controls::-webkit-scrollbar { display: none; }
  .controls button { flex: none; }
  /* Help stays reachable at the right end while the rest of the row scrolls under it. */
  .controls [data-action='help'] { position: sticky; right: 0; padding-left: 14px; background: var(--ink); box-shadow: none; }
  /* The labels name the parts, so the legend and caption step aside. */
  .model #model-blurb, .parts { display: none; }
}

@media (max-width: 640px) {
  .model { bottom: calc(var(--gutter) + 44px); }
  .model h1 { font-size: 30px; }
  body.compact .model h1 { font-size: 22px; }
  .controls { gap: 0 18px; }
  .cam { bottom: auto; top: calc(var(--gutter) + 30px); width: 112px; }
  .help-cols { grid-template-columns: 1fr; gap: 24px; }
  .help dl div { grid-template-columns: 6rem 1fr; }
  .guide { width: auto; }
  .guide:has([data-for='hand']:not([hidden])) .guide-head { display: none; }
  .guide [data-for='hand'] li span { display: none; }
  .guide [data-for='hand'] li b { width: auto; }
}

@media (prefers-reduced-motion: reduce) {
  .model h1, .parts, button, .guide li { transition: none; }
}

/* On small screens the guide already says what to do next, so the first-run hint steps aside. */
@media (max-width: 719px) {
  body:has(#guide:not([hidden])) .hint { display: none; }
}

/* On small screens the selected label sits over the model: give it a solid placard to stay readable. */
@media (max-width: 719px) {
  .label.active {
    width: min(300px, calc(100vw - 2 * var(--gutter)));
    max-width: none;
    padding: 10px 12px;
    border-left: 1px solid var(--part);
    background: var(--panel);
    text-shadow: none;
  }
}