/*
 * Web showroom. One full-viewport stage with the interface in fixed zones over it:
 * identity, sections and presenting along the top; where you stand at the left; the story
 * at the lower left; detail on demand at the right; the light moods along the bottom.
 * Separation is by alignment, then space, then a hairline. One flat plate per region keeps
 * text readable over the studio; there are no gradients, shadows or cards inside the plates.
 *
 * The layout is the Hilton client app's (review/conexion-01/app.css in that project); the
 * face is this project's: the remote's ground and blue, a text serif for what is said and
 * a plain sans for what is pressed.
 */
*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--stage); color: var(--ink);
  font: 400 var(--t-ui)/1.35 var(--font-ui);
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
  overflow: hidden;
}
h1, h2, h3, p, dl, dd { margin: 0; }
button, input, select { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; touch-action: manipulation; }
button:disabled { cursor: default; }
svg { width: 16px; height: 16px; flex: none; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
[hidden] { display: none !important; }
::selection { background: var(--accent); color: var(--accent-ink); }

/* Two rings: the ground-coloured halo keeps the blue ring visible over a
   bright softbox and a dark floor alike. */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; box-shadow: 0 0 0 5px var(--stage); }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip-link { position: fixed; left: var(--s-3); top: -80px; z-index: 50; padding: var(--s-3) var(--s-4); background: var(--accent); color: var(--accent-ink); font-weight: 600; text-decoration: none; }
.skip-link:focus { top: var(--s-3); }

.mono, .idx, .readout, .counter, .card-meta, output, kbd { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ---------- Stage ---------- */
.app { position: fixed; inset: 0; overflow: hidden; isolation: isolate; }
.stage { position: absolute; inset: 0; background: var(--stage); }
.stage canvas { position: absolute; display: block; outline-offset: -4px; touch-action: none; }
.stage canvas:focus-visible { box-shadow: none; }
.poster, .film { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.poster { transition: opacity var(--dur-veil) var(--ease-standard); pointer-events: none; }
[data-ready='true'] .poster { opacity: 0; }
.film { object-fit: contain; background: var(--stage); }
/* A flat veil in the ground colour: the title sits on it, and camera cuts
   pass behind it. Opacity only, so it is safe under reduced motion. */
.dim, .veil { position: absolute; inset: 0; background: var(--stage); opacity: 0; pointer-events: none; }
.dim { transition: opacity var(--dur-veil) var(--ease-standard); }
[data-mode='title'] .dim, [data-card='end'] .dim { opacity: .28; }
.veil { z-index: var(--z-veil); transition: opacity 160ms var(--ease-exit); }
.veil.is-up { opacity: 1; transition-duration: 160ms; }
.veil.is-lifting { transition: opacity var(--dur-enter) var(--ease-enter); }

/* ---------- HUD grid ---------- */
.hud {
  position: absolute; inset: 0; z-index: var(--z-hud);
  display: grid; gap: var(--s-4) var(--gutter);
  padding: var(--gutter);
  padding-top: max(var(--s-4), calc(var(--gutter) * .7));
  grid-template:
    'bar bar bar' auto
    'left . right' minmax(0, 1fr)
    'transport transport transport' auto / minmax(0, var(--panel)) minmax(0, 1fr) minmax(0, var(--sheet-w));
  pointer-events: none;      /* a drag on open scene reaches the room */
  transition: opacity var(--dur-enter) var(--ease-enter);
}
.hud > * { min-width: 0; min-height: 0; }
.hud :is(button, a, input, label, .plate) { pointer-events: auto; }
[data-mode='title'] .hud > :not(.bar, .sheet), [data-card='end'] .hud > :not(.bar, .sheet) { display: none; }
/* Behind a card or a film the room is a picture, not a control. */
[data-mode='title'] .stage canvas, [data-mode='film'] .stage canvas, [data-card='end'] .stage canvas { pointer-events: none; }

.plate {
  background: var(--plate);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border: 1px solid var(--rule); border-radius: var(--radius);
}

/* Coming from a card, the panels arrive after it has left: a short rise, once. */
.narrative, .views, .caption, .transport { transition: opacity var(--dur-enter) var(--ease-enter), transform var(--dur-enter) var(--ease-enter); }
[data-arriving] :is(.narrative, .views, .caption, .transport) { opacity: 0; transform: translateY(var(--rise)); transition: none; }

/* ---------- Top bar ---------- */
.bar { grid-area: bar; display: grid; grid-template-columns: 1fr auto 1fr; align-items: start; gap: var(--s-4); transition: opacity var(--dur-veil) var(--ease-standard); }
.wordmark { justify-self: start; display: inline-flex; align-items: baseline; gap: var(--s-3); height: 44px; padding: 0 var(--s-4); line-height: 42px; color: var(--ink); text-decoration: none; white-space: nowrap; }
.wordmark b { font-weight: 600; letter-spacing: .04em; font-size: var(--t-ui); }
.wordmark span { color: var(--muted); font-size: var(--t-ui); }
.modes { display: flex; height: 44px; padding: 0 var(--s-1); }
.modes button { position: relative; padding: 0 var(--s-4); color: var(--muted); font-weight: 500; white-space: nowrap; transition: color var(--dur-exit) var(--ease-standard); }
.modes button:hover:not(:disabled) { color: var(--ink); }
.modes button:disabled { opacity: .45; }
.modes button[aria-pressed='true'] { color: var(--ink); }
.modes button[aria-pressed='true']::after { content: ''; position: absolute; left: var(--s-4); right: var(--s-4); bottom: -1px; height: 2px; background: var(--accent); }
.bar-actions { justify-self: end; display: flex; align-items: center; gap: var(--s-1); height: 44px; padding: 0 var(--s-2); }

/* ---------- Buttons ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--s-3); min-height: 44px; padding: 0 var(--s-4); border-radius: var(--radius); font-weight: 600; white-space: nowrap; transition: background-color var(--dur-exit) var(--ease-standard), color var(--dur-exit) var(--ease-standard), border-color var(--dur-exit) var(--ease-standard), opacity var(--dur-exit); }
.btn:active:not(:disabled) { transform: translateY(1px); transition-duration: var(--dur-press); }
/* One filled action per state: the next thing to do. */
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); }
.btn-primary:disabled { background: rgb(241 238 231 / .14); color: var(--muted); }
.btn-large { min-height: calc(52px * var(--density)); padding: 0 var(--s-5); font-size: var(--t-body); }
.btn-quiet { border: 1px solid var(--rule-strong); color: var(--ink); font-weight: 500; }
.btn-quiet:hover { background: var(--hover); }
.btn-icon { width: 44px; padding: 0; border: 1px solid var(--rule-strong); color: var(--ink); }
.btn-icon:hover:not(:disabled) { background: var(--hover); }
.btn-icon:disabled { opacity: .35; }
.btn-bare { border-color: transparent; color: var(--muted); }
.btn-bare:hover { color: var(--ink); }
.btn-text { display: inline-flex; align-items: center; gap: var(--s-2); min-height: 44px; padding: 0 var(--s-3); color: var(--ink-2); font-weight: 500; white-space: nowrap; text-underline-offset: 5px; transition: color var(--dur-exit); }
.btn-text:hover:not(:disabled) { color: var(--ink); text-decoration: underline; text-decoration-thickness: 1px; }
.btn-text:disabled { opacity: .45; }
.btn-text[aria-pressed='true'] { color: var(--accent); }

.segmented { display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; border: 1px solid var(--rule-strong); border-radius: var(--radius); }
.segmented-2 { grid-auto-flow: row; grid-template-columns: 1fr 1fr; }
.segmented button { min-height: 40px; padding: 0 var(--s-2); color: var(--ink-2); font-weight: 500; border-left: 1px solid var(--rule); transition: background-color var(--dur-exit), color var(--dur-exit); }
.segmented button:first-child { border-left: 0; }
.segmented-2 button:nth-child(odd) { border-left: 0; }
.segmented-2 button:nth-child(n + 3) { border-top: 1px solid var(--rule); }
.segmented button:hover { background: var(--hover); color: var(--ink); }
.segmented button[aria-pressed='true'] { background: var(--ink); color: var(--stage); font-weight: 600; }

/* ---------- Where you stand ---------- */
.views { grid-area: left; align-self: start; width: var(--rail-w); max-height: 100%; display: flex; flex-direction: column; padding: var(--s-4) 0 var(--s-2); overflow: hidden; }
.views h2 { padding: 0 var(--s-4) var(--s-2); font-size: var(--t-ui); font-weight: 600; }
.view-list { overflow: auto; overscroll-behavior: contain; scrollbar-width: thin; }
.view-group { padding: var(--s-3) var(--s-4) var(--s-1); color: var(--muted); font-size: var(--t-meta); border-top: 1px solid var(--rule); }
.view-group:first-child { border-top: 0; padding-top: var(--s-1); }
.view-list button { position: relative; display: grid; grid-template-columns: 26px 1fr auto; align-items: center; gap: var(--s-1); width: 100%; min-height: calc(34px * var(--density)); padding: 0 var(--s-4); text-align: left; color: var(--ink-2); transition: background-color var(--dur-exit), color var(--dur-exit); }
.view-list button:hover { background: var(--hover); color: var(--ink); }
.view-list .idx { color: var(--muted); font-size: var(--t-meta); }
.view-list .value { color: var(--muted); font: 400 var(--t-meta)/1 var(--font-mono); }
.view-list button[aria-pressed='true'] { color: var(--ink); font-weight: 600; }
.view-list button[aria-pressed='true']::before { content: ''; position: absolute; left: 0; top: 6px; bottom: 6px; width: 2px; background: var(--accent); }
.view-list button[aria-pressed='true'] .idx { color: var(--accent); }
.reset { margin: var(--s-1) var(--s-1) 0; align-self: flex-start; color: var(--accent); }

/* ---------- The story ---------- */
.narrative { grid-area: left; align-self: end; display: grid; gap: var(--s-5); padding: var(--s-5); max-height: 100%; overflow: auto; }
.narrative-copy { display: grid; gap: var(--s-3); transition: opacity var(--dur-enter) var(--ease-enter), transform var(--dur-enter) var(--ease-enter); }
/* Leaving is faster than arriving, and nothing slides while the camera travels. */
.narrative-copy.is-out { opacity: 0; transition: opacity var(--dur-exit) var(--ease-exit); }
.narrative h2 { font: 400 var(--t-h2)/1.12 var(--font-display); font-variation-settings: 'opsz' 40; letter-spacing: -.012em; text-wrap: balance; }
.narrative .idx { margin-right: .6em; color: var(--muted); font-size: .56em; font-weight: 400; letter-spacing: 0; vertical-align: .36em; }
.lede { color: var(--ink-2); font-size: var(--t-body); line-height: 1.5; max-width: 44ch; text-wrap: pretty; }
.readout { display: flex; flex-wrap: wrap; gap: var(--s-1) var(--s-4); color: var(--muted); font-size: var(--t-meta); }
.readout span + span::before, .card-meta span + span::before { content: ''; display: inline-block; width: 3px; height: 3px; margin-right: var(--s-4); vertical-align: middle; background: currentColor; }
.narrative-actions { display: grid; grid-template-columns: auto 1fr; gap: var(--s-2); }
#beat-next { justify-content: flex-start; padding: 0 var(--s-4); }
.next-name { margin-left: auto; font-weight: 450; opacity: .78; overflow: hidden; text-overflow: ellipsis; }

/* ---------- Detail on demand ---------- */
.sheet { grid-area: right; align-self: end; display: flex; flex-direction: column; max-height: 100%; overflow: hidden; animation: sheet-in var(--dur-sheet) var(--ease-enter); }
@keyframes sheet-in { from { opacity: 0; transform: translateX(var(--rise)); } }
.sheet-head { display: flex; align-items: center; justify-content: space-between; padding: var(--s-2) var(--s-2) var(--s-2) var(--s-5); border-bottom: 1px solid var(--rule); }
.sheet-head h2 { font-size: var(--t-body); font-weight: 600; }
.sheet-body { padding: var(--s-4) var(--s-5) var(--s-5); overflow: auto; overscroll-behavior: contain; scrollbar-width: thin; }
.sheet-body section { display: grid; gap: var(--s-4); }
.sheet-body h3 { font-size: var(--t-ui); font-weight: 600; }
.sheet-body h3:not(:first-child) { padding-top: var(--s-4); border-top: 1px solid var(--rule); }
.sheet-lede { color: var(--ink-2); line-height: 1.5; }
.fine { color: var(--muted); font-size: var(--t-meta); line-height: 1.5; }
.count { color: var(--muted); font-size: var(--t-meta); }
.count output { color: var(--ink); }
.check { display: flex; align-items: center; gap: var(--s-3); min-height: 32px; color: var(--ink-2); cursor: pointer; }
.check input { width: 18px; height: 18px; margin: 0; accent-color: var(--accent); }
.field { display: grid; gap: var(--s-1); }
.field-line { display: flex; justify-content: space-between; align-items: baseline; }
.field-line label { font-weight: 600; }
input[type='range'] { width: 100%; height: 28px; margin: 0; accent-color: var(--accent); }

.notes { display: grid; grid-template-columns: auto 1fr; gap: var(--s-3) var(--s-4); }
.notes dt { font-weight: 600; }
.notes dd { color: var(--ink-2); line-height: 1.5; }
.keys { display: grid; grid-template-columns: auto 1fr; gap: 0 var(--s-4); }
.keys dt, .keys dd { padding: var(--s-2) 0; border-top: 1px solid var(--rule); }
.keys dt:first-of-type, .keys dt:first-of-type + dd { border-top: 0; }
.keys dt { font: 500 var(--t-meta)/1.6 var(--font-mono); color: var(--ink); white-space: nowrap; }
.keys dd { color: var(--ink-2); }

/* A detail view's caption: the headset app's own words for the part in view. */
.caption { grid-area: left; align-self: end; display: grid; gap: var(--s-1); max-width: var(--panel); padding: var(--s-4) var(--s-5); color: var(--ink-2); line-height: 1.5; }
.caption b { color: var(--ink); font: 400 var(--t-h3)/1.15 var(--font-display); font-variation-settings: 'opsz' 32; }

/* Configuration: a chip of the real colour, pressed like any other button. */
.sheet-body h3 output { margin-left: var(--s-2); color: var(--muted); font: 400 var(--t-meta)/1 var(--font-mono); }
.swatches { display: flex; flex-wrap: wrap; gap: var(--s-2); }
.swatch { position: relative; width: 44px; height: 44px; border-radius: var(--radius); }
.swatch i { position: absolute; inset: 5px; border-radius: 2px; background: var(--chip); border: 1px solid rgb(237 235 230 / .28); }
.swatch:hover i { border-color: var(--ink); }
.swatch[aria-pressed='true'] { outline: 2px solid var(--accent); outline-offset: -2px; }
.swatch[aria-pressed='true'] i { inset: 7px; border-color: transparent; }

.toggles { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s-2); }
.toggle { min-height: 40px; padding: 0 var(--s-2); border: 1px solid var(--rule-strong); border-radius: var(--radius); color: var(--ink-2); font-weight: 500; white-space: nowrap; transition: background-color var(--dur-exit), color var(--dur-exit), border-color var(--dur-exit); }
.toggle:hover:not(:disabled) { background: var(--hover); color: var(--ink); }
.toggle:disabled { opacity: .4; }
.toggle[aria-pressed='true'] { background: var(--ink); border-color: var(--ink); color: var(--stage); font-weight: 600; }

#sound .i-mute, #sound[aria-pressed='false'] .i-waves { display: none; }
#sound[aria-pressed='false'] .i-mute { display: block; }
#sound[aria-pressed='true'] { color: var(--ink-2); }
#sound[aria-pressed='false'] { color: var(--muted); }

/* ---------- The mood rail ---------- */
.transport { grid-area: transport; position: relative; display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: center; gap: var(--s-5); min-height: calc(60px * var(--density)); padding: var(--s-2) var(--s-4) var(--s-2) var(--s-2); }
.transport-toggle { display: inline-flex; align-items: center; gap: var(--s-2); min-height: 44px; padding: 0 var(--s-4) 0 var(--s-3); white-space: nowrap; border: 1px solid var(--rule-strong); border-radius: var(--radius); color: var(--ink); font-weight: 500; transition: background-color var(--dur-exit); }
.transport-toggle:hover { background: var(--hover); }
.transport-toggle .i-play { display: none; fill: currentColor; stroke: none; }
.transport-toggle[aria-pressed='false'] .i-play { display: block; }
.transport-toggle[aria-pressed='false'] .i-pause { display: none; }
.transport-toggle[aria-pressed='false'] { color: var(--ink-2); }
.segments { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(0, 1fr); gap: 3px; align-items: stretch; }
.segments button { display: flex; align-items: baseline; gap: var(--s-2); padding: var(--s-3) var(--s-2) var(--s-2) 0; border-top: 2px solid var(--rule-strong); text-align: left; color: var(--muted); white-space: nowrap; transition: color var(--dur-exit), border-color var(--dur-exit); min-width: 0; }
.segments button:hover { color: var(--ink); }
.segments .num { font: 400 var(--t-meta)/1.2 var(--font-mono); flex: none; }
.segments .name { font-weight: 500; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.segments button[data-state='done'] { border-color: var(--ink-2); color: var(--ink-2); }
.segments button[aria-pressed='true'] { border-color: var(--accent); color: var(--ink); }
.segments button[aria-pressed='true'] .name { font-weight: 600; }
.segments button[aria-pressed='true'] .num { color: var(--accent); }
.transport-side { display: flex; align-items: center; gap: var(--s-3); }
.counter { color: var(--ink-2); font-size: var(--t-ui); white-space: nowrap; }
/* All that stays up while presenting: a hairline of how far along the story is. */
.progress { position: absolute; left: -1px; bottom: -1px; height: 2px; width: calc(var(--progress, 0) * (100% + 2px)); background: var(--accent); opacity: 0; pointer-events: none; }

[data-mode='walk'] :is(#configure-open, #car-open, #resume), [data-mode='film'] :is(#configure-open, #car-open, #resume), [data-mode='explore'] .counter { display: none; }
[data-mode='film'] .hud > :is(.views, .narrative, .caption) { display: none; }

/* ---------- Title and end cards ---------- */
.card { position: absolute; z-index: var(--z-card); left: 0; right: 0; bottom: 0; display: grid; gap: var(--s-5); max-width: 980px; padding: var(--gutter); padding-bottom: clamp(var(--s-6), 7vh, var(--s-8)); animation: card-in var(--dur-veil) var(--ease-enter) backwards; }
@keyframes card-in { from { opacity: 0; transform: translateY(var(--rise)); } }
.card.is-leaving { opacity: 0; transition: opacity var(--dur-exit) var(--ease-exit); }
.card h1 { display: grid; gap: .1em; font: 300 var(--t-h1)/.98 var(--font-display); font-variation-settings: 'opsz' 72; letter-spacing: -.022em; }
.card h1 b { font-weight: 300; }
.card h1 span { color: var(--ink-2); font: 400 .3em/1.2 var(--font-ui); letter-spacing: 0; }
.card h2 { font: 300 clamp(2.25rem, 1.2rem + 3.4vw, 4.5rem)/1 var(--font-display); font-variation-settings: 'opsz' 72; letter-spacing: -.022em; max-width: 14ch; text-wrap: balance; }
.card-lede { max-width: 46ch; color: var(--ink); font-size: var(--t-lede); line-height: 1.4; text-wrap: pretty; }
.card-meta { display: flex; flex-wrap: wrap; gap: var(--s-1) var(--s-4); color: var(--muted); font-size: var(--t-meta); }
.card-actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--s-2) var(--s-3); }
.card-status { min-height: 1.4em; color: var(--muted); font-size: var(--t-meta); }
.card-status.is-alert { color: var(--alert); }
[data-ready='true'] .card-status:not(.is-alert) { visibility: hidden; }
/* A thin line while the room loads; it never claims a percentage it does not have. */
.load-line { position: absolute; left: 0; bottom: 0; height: 2px; width: 100%; background: var(--accent); transform-origin: left; animation: load 1.6s var(--ease-standard) infinite; }
@keyframes load { 0% { transform: scaleX(0); } 60% { transform: scaleX(1); opacity: 1; } 100% { transform: scaleX(1); opacity: 0; } }
[data-ready='true'] .load-line, [data-ready='failed'] .load-line { display: none; }

/* ---------- Small notices ---------- */
.hint, .notice { position: absolute; left: 50%; z-index: var(--z-card); translate: -50% 0; padding: var(--s-2) var(--s-4); background: var(--plate); border: 1px solid var(--rule); border-radius: var(--radius); color: var(--ink); white-space: nowrap; pointer-events: none; }
.hint { top: 38%; animation: hint 3.2s var(--ease-standard) forwards; }
@keyframes hint { 0% { opacity: 0; } 10%, 80% { opacity: 1; } 100% { opacity: 0; } }
.notice { top: calc(var(--gutter) + 60px); white-space: normal; max-width: min(560px, 80vw); text-align: center; }
.blank { position: fixed; inset: 0; z-index: var(--z-blank); background: #000; cursor: none; }

/* ---------- Presenting ---------- */
/* Essential text stays out of the outer 5% of a projected picture. */
[data-presenting='true'] .hud { padding: max(var(--gutter), 5vh) max(var(--gutter), 5vw); }
[data-presenting='true'] .card { padding-left: max(var(--gutter), 5vw); padding-bottom: max(var(--s-7), 7vh); }
/* In front of an audience the page does not teach its gestures, and a key pressed after a
   drag does not ring the whole stage: the presenter knows where the keys go. */
[data-presenting='true'] .hint { display: none; }
[data-presenting='true'] .stage canvas:focus-visible { outline: none; }
/* The list of viewpoints keeps its ordinary rows, so all eleven and the reset still fit a 16:9 screen. */
[data-presenting='true'] .view-list button { min-height: 34px; }
/* Presenting is driven by keys or a clicker, so the story panel is copy only. */
[data-presenting='true'] .narrative-actions { display: none; }
[data-presenting='true'] :is(.bar, .views, .sheet, .transport) { transition: opacity var(--dur-enter) var(--ease-enter); }
/* After 2.5 s without the pointer the chrome and the cursor step back. What
   stays up is the story and a hairline of how far through it the room is. */
[data-presenting='true'][data-idle] .app { cursor: none; }
[data-presenting='true'][data-idle] :is(.bar, .views, .sheet, .hint, .caption) { opacity: 0; pointer-events: none; transition: opacity var(--dur-veil) var(--ease-exit); }
[data-presenting='true'][data-idle] .transport { background: none; border-color: transparent; -webkit-backdrop-filter: none; backdrop-filter: none; pointer-events: none; }
[data-presenting='true'][data-idle] .transport > :not(.progress) { opacity: 0; transition: opacity var(--dur-veil) var(--ease-exit); }
[data-presenting='true'][data-idle] [data-mode='walk'] .progress { opacity: 1; transition: opacity var(--dur-veil) var(--ease-exit); }

/* ---------- Narrower windows ---------- */
@media (max-width: 1180px) {
  :root { --panel: 380px; --sheet-w: 340px; --rail-w: 240px; }
  /* The current segment takes the room its name needs. */
  .segments { display: flex; }
  .segments button { flex: 1 1 0; }
  .segments button[aria-pressed='true'] { flex: 1.9 1 0; }
  .segments button:not([aria-pressed='true']) .num { display: none; }
}
@media (max-width: 960px) {
  .wordmark span { display: none; }
  .hud { grid-template-columns: minmax(0, var(--panel)) minmax(0, 1fr); grid-template-areas: 'bar bar' 'left right' 'transport transport'; }
  .sheet { justify-self: end; width: min(100%, var(--sheet-w)); }
  .segments button:not([aria-pressed='true']) .name { font-size: var(--t-meta); }
  .transport-side .btn-quiet { padding: 0 var(--s-3); }
}

/* Phones: stop overlaying. The room becomes a block at the top and the story,
   controls and detail flow below it on the same ground; one finger scrolls. */
@media (max-width: 700px) {
  body { overflow: auto; }
  .app { position: static; overflow: visible; min-height: 100svh; display: flex; flex-direction: column; }
  .stage { position: sticky; top: 0; z-index: 1; height: 56svh; flex: none; }
  .stage canvas { touch-action: pan-y; }
  .dim, .veil { position: absolute; height: 56svh; inset: 0 0 auto; z-index: 2; }
  .hud { position: static; display: flex; flex-direction: column; gap: var(--s-3); padding: var(--s-3) var(--s-4) var(--s-6); z-index: 3; background: var(--stage); }
  .hud > .bar { order: -1; position: fixed; top: 0; left: 0; right: 0; z-index: 4; padding: var(--s-2) var(--s-3); grid-template-columns: auto 1fr auto; gap: var(--s-2); }
  .wordmark { padding: 0 var(--s-3); }
  .modes button { padding: 0 var(--s-2); }
  .modes { justify-self: center; }
  /* Presenting is for a projector or a monitor; a phone has neither. */
  .bar-actions { display: none; }
  .plate { -webkit-backdrop-filter: none; backdrop-filter: none; }
  .views, .narrative, .caption, .sheet, .transport { width: auto; max-width: none; max-height: none; align-self: stretch; }
  /* The rail gets the full width; its controls sit on the row under it. */
  .hud > .transport { order: 1; display: flex; flex-wrap: wrap; align-items: center; gap: var(--s-3); padding: var(--s-2) var(--s-3) var(--s-3); }
  .hud > .transport .segments { order: -1; flex: 1 1 100%; }
  .hud > .narrative { order: 2; border: 0; background: none; padding: var(--s-2) 0; }
  .hud > .views { order: 3; }
  .hud > .caption { order: 2; }
  .hud > .sheet { order: 2; }
  .transport-side { flex-wrap: wrap; margin-left: auto; }
  /* The current segment takes the room for its name; the rest are ticks. */
  .segments { display: flex; }
  .segments button { flex: 1 1 0; }
  .segments button[aria-pressed='true'] { flex: 6 1 0; }
  .segments button:not([aria-pressed='true']) .name { display: none; }
  .segments button { min-height: 44px; }
  .card { position: relative; z-index: 3; margin-top: -28svh; padding: var(--s-4); background: none; }
  .card h1 { font-size: clamp(2.5rem, 13vw, 3.6rem); }
  .hint { display: none; }
  .view-list button, .segmented button, .toggle { min-height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  .load-line { animation: none; opacity: .6; }
  .card, .sheet { animation-duration: 1ms; }
}
@media (forced-colors: active) {
  .plate { background: Canvas; color: CanvasText; border: 1px solid; }
}