/* ============================================================
   IMMERSIVE AUDIO GUIDE — page-scoped
   knowledge/what-is-truehd-atmos.html

   Loaded only by this route. Every component is authored twice:
   once as static stacked content (the no-JavaScript state, which is
   also what a crawler sees), and once under `.is-enhanced`, which the
   page script adds only after it has successfully wired a selector.
   ============================================================ */

.immersive-audio-guide {
  --ia-line: rgba(201, 169, 110, 0.16);
  --ia-line-strong: rgba(201, 169, 110, 0.34);
  --ia-panel: linear-gradient(
    162deg,
    rgba(19, 17, 11, 0.94),
    rgba(7, 6, 4, 0.96)
  );
  --ia-inset: rgba(0, 0, 0, 0.42);
  --ia-micro: 0.62rem;
}

.immersive-audio-guide .ia-micro-label,
.immersive-audio-guide .ia-facts dt,
.immersive-audio-guide .ia-stack__label,
.immersive-audio-guide .ia-stack__title,
.immersive-audio-guide .ia-stack__examples-title,
.immersive-audio-guide .ia-rail__item,
.immersive-audio-guide .ia-status,
.immersive-audio-guide .ia-avr__notice,
.immersive-audio-guide .ia-diagram__node,
.immersive-audio-guide .ia-carrier__part {
  font-family: var(--font-body);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ── Chapter A — the format stack ─────────────────────────── */

.ia-stack {
  align-self: center;
  width: 100%;
  padding: clamp(1.4rem, 2.6vw, 2rem);
  border: 1px solid var(--ia-line);
  border-radius: 10px;
  background:
    radial-gradient(
      ellipse at 12% 0%,
      rgba(201, 169, 110, 0.09),
      transparent 62%
    ),
    var(--ia-panel);
}

.ia-stack__title,
.ia-stack__examples-title {
  margin: 0 0 1.1rem;
  color: var(--bronze);
  font-size: var(--ia-micro);
  font-weight: 600;
}

.ia-stack__ladder {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: ia-stage;
}

.ia-stack__stage {
  position: relative;
  counter-increment: ia-stage;
  padding: 0 0 1.05rem 2.4rem;
}

.ia-stack__stage::before {
  content: counter(ia-stage, decimal-leading-zero);
  position: absolute;
  top: 0.05rem;
  left: 0;
  width: 1.55rem;
  color: var(--bronze-dim);
  font-family: var(--font-body);
  font-size: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.1em;
}

/* The spine that makes the six stages read as one chain rather than
   six unrelated rows. */
.ia-stack__stage::after {
  content: '';
  position: absolute;
  top: 1.15rem;
  bottom: 0.15rem;
  left: 0.52rem;
  width: 1px;
  background: linear-gradient(
    to bottom,
    rgba(201, 169, 110, 0.4),
    rgba(201, 169, 110, 0.06)
  );
}

.ia-stack__stage:last-child {
  padding-bottom: 0;
}

.ia-stack__stage:last-child::after {
  display: none;
}

.ia-stack__label {
  display: block;
  margin-bottom: 0.18rem;
  color: var(--text-muted);
  font-size: var(--ia-micro);
  font-weight: 600;
}

.ia-stack__value {
  display: block;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1rem, 1.55vw, 1.15rem);
  line-height: 1.35;
}

.ia-stack__examples {
  margin-top: 1.5rem;
  padding-top: 1.35rem;
  border-top: 1px solid var(--ia-line);
}

.ia-example-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.ia-example,
.ia-example__button {
  display: block;
  width: 100%;
  text-align: left;
}

.ia-example {
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--ia-line);
  border-radius: 6px;
  background: var(--ia-inset);
}

.ia-example__name,
.ia-example__chain {
  display: block;
}

.ia-example__name {
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.ia-example__chain {
  margin-top: 0.2rem;
  color: var(--text-secondary);
  font-size: 0.8rem;
  line-height: 1.45;
}

/* Enhanced: the four examples become a radio group driving the ladder. */
.ia-stack.is-enhanced .ia-example {
  padding: 0;
  border: 0;
  background: none;
}

.ia-stack.is-enhanced .ia-example__button {
  padding: 0.62rem 0.8rem;
  border: 1px solid var(--ia-line);
  border-radius: 6px;
  background: var(--ia-inset);
  color: inherit;
  cursor: pointer;
  font: inherit;
  transition:
    border-color 0.25s var(--ease-out),
    background 0.25s var(--ease-out),
    transform 0.25s var(--ease-out);
}

.ia-stack.is-enhanced .ia-example__button:hover {
  border-color: var(--ia-line-strong);
}

.ia-stack.is-enhanced .ia-example__button.is-active {
  border-color: var(--bronze-dim);
  background: linear-gradient(
    140deg,
    rgba(201, 169, 110, 0.14),
    rgba(7, 6, 4, 0.7)
  );
  transform: translateX(2px);
}

.ia-stack.is-enhanced .ia-example__button.is-active .ia-example__name {
  color: var(--bronze-light);
}

/* ── Selector rails (comparison + explorer) ───────────────── */

.ia-rail {
  display: flex;
  gap: 0.45rem;
  margin: 0 0 1.5rem;
  padding-bottom: 0.35rem;
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x proximity;
}

.ia-rail__item {
  flex: 0 0 auto;
  padding: 0.62rem 0.95rem;
  border: 1px solid var(--ia-line);
  border-radius: 999px;
  background: var(--ia-inset);
  color: var(--text-secondary);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  scroll-snap-align: start;
  text-transform: uppercase;
  white-space: nowrap;
  transition:
    border-color 0.25s var(--ease-out),
    background 0.25s var(--ease-out),
    color 0.25s var(--ease-out);
}

.ia-rail__item:hover {
  border-color: var(--ia-line-strong);
  color: var(--text-primary);
}

.ia-rail__item.is-active {
  border-color: var(--bronze-dim);
  background: linear-gradient(
    140deg,
    rgba(201, 169, 110, 0.16),
    rgba(7, 6, 4, 0.7)
  );
  color: var(--bronze-light);
}

.immersive-audio-guide :focus-visible {
  outline: 2px solid var(--bronze-dim);
  outline-offset: 2px;
}

/* ── Shared fact lists ────────────────────────────────────── */

.ia-facts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.05rem;
  margin: 0;
}

.ia-fact {
  display: grid;
  grid-template-columns: minmax(0, 10.5rem) minmax(0, 1fr);
  gap: 0.35rem 1.25rem;
  padding: 0.7rem 0;
  border-top: 1px solid rgba(201, 169, 110, 0.09);
}

.ia-facts dt {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.64rem;
  font-weight: 600;
}

.ia-facts dd {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.86rem;
  line-height: 1.55;
}

.ia-fact--myth dd {
  color: var(--text-primary);
}

.ia-facts--compact .ia-fact {
  grid-template-columns: minmax(0, 8rem) minmax(0, 1fr);
  padding: 0.55rem 0;
}

.ia-facts--compact dd {
  font-size: 0.82rem;
}

/* ── Chapter B — format comparison ────────────────────────── */

.ia-compare {
  margin: clamp(2rem, 4vw, 2.75rem) 0 0;
}

.ia-compare__panels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.ia-format {
  padding: clamp(1.4rem, 3vw, 2.25rem);
  border: 1px solid var(--ia-line);
  border-radius: 10px;
  background: var(--ia-panel);
  scroll-margin-top: 6rem;
}

.ia-format__name {
  margin: 0 0 0.55rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 400;
  line-height: 1.15;
}

.ia-format__lede {
  max-width: 58ch;
  margin: 0 0 1.35rem;
  color: var(--text-secondary);
  font-size: 0.96rem;
  line-height: 1.6;
}

/* Carrier / metadata relationship, drawn as two joined segments so the
   dependency is visible rather than asserted in prose. */
.ia-carrier {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  margin: 0 0 1.4rem;
  border: 1px solid var(--ia-line);
  border-radius: 6px;
  overflow: hidden;
}

.ia-carrier__part {
  flex: 1 1 15rem;
  min-width: 0;
  padding: 0.72rem 0.85rem;
  font-size: 0.6rem;
  font-weight: 600;
  line-height: 1.5;
}

.ia-carrier__part--carrier {
  background: linear-gradient(
    120deg,
    rgba(201, 169, 110, 0.16),
    rgba(201, 169, 110, 0.06)
  );
  color: var(--bronze-light);
}

.ia-carrier__part--meta {
  background: var(--ia-inset);
  color: var(--text-muted);
}

.ia-compare.is-enhanced .ia-format {
  display: none;
}

.ia-compare.is-enhanced .ia-format.is-active {
  display: block;
}

/* ── Chapter C — source and signal-path explorer ──────────── */

.ia-explorer {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3vw, 2.25rem);
  margin: clamp(2rem, 4vw, 2.75rem) 0;
}

.ia-axis__title {
  margin: 0 0 1rem;
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.ia-axis__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.ia-card {
  padding: clamp(1.15rem, 2.4vw, 1.6rem);
  border: 1px solid var(--ia-line);
  border-radius: 8px;
  background: var(--ia-panel);
  scroll-margin-top: 6rem;
}

.ia-card__name {
  margin: 0 0 0.65rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 2.2vw, 1.4rem);
  font-weight: 500;
  line-height: 1.2;
}

.ia-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.88rem;
  line-height: 1.6;
}

.ia-explorer__axis.is-enhanced .ia-card {
  display: none;
}

.ia-explorer__axis.is-enhanced .ia-card.is-active {
  display: block;
}

/* Path diagram — the five transports, drawn rather than described. */
.ia-diagram {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  gap: 0.3rem;
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
}

.ia-diagram__node {
  flex: 1 1 auto;
  min-width: 0;
  padding: 0.6rem 0.65rem;
  border: 1px solid rgba(201, 169, 110, 0.2);
  border-radius: 4px;
  background: var(--ia-inset);
  color: var(--text-primary);
  font-size: 0.66rem;
  font-weight: 600;
  text-align: center;
}

.ia-diagram__node + .ia-diagram__node {
  position: relative;
}

.ia-diagram__node + .ia-diagram__node::before {
  content: '→';
  position: absolute;
  top: 50%;
  left: -0.31rem;
  transform: translate(-50%, -50%);
  color: var(--bronze-dim);
  font-size: 0.7rem;
  letter-spacing: 0;
}

/* A visually narrower segment for the reduced-capability return channel:
   the constraint is stated in words as well, never by shape alone. */
.ia-diagram__node--narrow {
  flex: 0 1 4.5rem;
  border-style: dashed;
  color: var(--text-muted);
}

/* Statuses carry their own words. Colour and glyph are reinforcement,
   never the sole carrier of meaning, and no status uses red or green. */
.ia-status {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  margin-right: 0.4rem;
  padding: 0.28rem 0.6rem;
  border: 1px solid var(--ia-line-strong);
  border-radius: 3px;
  color: var(--bronze-light);
  font-size: 0.68rem;
  font-weight: 600;
}

.ia-status::before {
  font-size: 0.72rem;
}

.ia-status--supports::before {
  content: '✓';
}

.ia-status--device::before {
  content: '◎';
}

.ia-status--fallback::before {
  content: '↓';
}

.ia-status--none::before {
  content: '✕';
}

.ia-status--verify::before {
  content: '?';
}

.ia-status--device,
.ia-status--verify {
  border-color: var(--ia-line);
  color: var(--text-primary);
}

.ia-status--fallback,
.ia-status--none {
  border-style: dashed;
  color: var(--text-muted);
}

/* Names the pairing so the verdict reads as a matrix result rather than an
   echo of the selected path card. */
.ia-verdict__pairing {
  display: block;
  margin-bottom: 0.55rem;
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.ia-verdict {
  /* The global `p { max-width: 60ch }` would otherwise keep the verdict
     inside one explorer column instead of spanning both. */
  max-width: none;
  margin: 0;
  padding: clamp(1.1rem, 2.4vw, 1.5rem);
  border: 1px solid var(--ia-line);
  border-left: 2px solid var(--bronze-dim);
  border-radius: 6px;
  background: var(--ia-inset);
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.65;
}

/* Deeper dives — preserves the bitstream / Direct Play / eARC anchors. */
.ia-dives {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.85rem;
  margin: clamp(1.75rem, 3vw, 2.5rem) 0;
}

.ia-dive {
  display: block;
  padding: 1rem 1.15rem;
  border: 1px solid var(--ia-line);
  border-radius: 6px;
  background: var(--ia-inset);
  scroll-margin-top: 6rem;
  text-decoration: none;
  transition: border-color 0.25s var(--ease-out);
}

.ia-dive:hover {
  border-color: var(--ia-line-strong);
}

.ia-dive strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.ia-dive span {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.55;
}

/* ── Chapter D — disc vs streaming, and the AVR display ───── */

.ia-duo {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 2.5vw, 2rem);
  margin: clamp(1.75rem, 3vw, 2.5rem) 0 1.5rem;
}

.ia-duo__side {
  padding: clamp(1.35rem, 2.6vw, 1.9rem);
  border: 1px solid var(--ia-line);
  border-radius: 8px;
  background: var(--ia-panel);
}

.ia-duo__title {
  margin: 0 0 1rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.4vw, 1.6rem);
  font-weight: 400;
}

.ia-duo__breaks {
  margin: 0 0 1rem;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.8rem;
  line-height: 1.5;
}

.ia-duo__breaks span {
  display: block;
  margin-bottom: 0.15rem;
  color: var(--bronze);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.ia-duo__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.ia-duo__list li {
  position: relative;
  padding: 0.55rem 0 0.55rem 1.35rem;
  border-top: 1px solid rgba(201, 169, 110, 0.09);
  color: var(--text-secondary);
  font-size: 0.88rem;
  line-height: 1.55;
}

.ia-duo__list li::before {
  content: '';
  position: absolute;
  top: 1.05rem;
  left: 0;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--bronze-dim);
}

.ia-note {
  max-width: 62ch;
  margin: 0 0 clamp(2rem, 4vw, 2.75rem);
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  font-style: italic;
  line-height: 1.5;
}

.ia-avr {
  margin-top: clamp(2.25rem, 4vw, 3.25rem);
}

.ia-avr__heading {
  margin: 0 0 0.5rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.6vw, 1.75rem);
  font-weight: 400;
}

.ia-avr__notice {
  margin: 0 0 1.5rem;
  color: var(--bronze);
  font-size: var(--ia-micro);
  font-weight: 600;
}

.ia-avr__gallery {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.ia-avr__unit {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-content: start;
  gap: 0.9rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--ia-line);
  border-radius: 8px;
  background: var(--ia-panel);
}

/* A brand-neutral rendering of an AVR front panel: drawn in CSS, copied
   from no manufacturer interface. */
.ia-avr__panel {
  display: block;
  padding: 1rem 1.1rem;
  border: 1px solid rgba(201, 169, 110, 0.22);
  border-radius: 4px;
  background:
    repeating-linear-gradient(
      to bottom,
      rgba(255, 255, 255, 0.022) 0 1px,
      transparent 1px 3px
    ),
    linear-gradient(160deg, rgba(10, 9, 6, 0.95), rgba(4, 4, 3, 0.98));
  box-shadow: inset 0 0 22px rgba(0, 0, 0, 0.65);
}

.ia-avr__main,
.ia-avr__sub {
  display: block;
  font-family: var(--font-mono);
  text-transform: uppercase;
}

.ia-avr__main {
  color: var(--bronze-light);
  font-size: clamp(0.85rem, 1.7vw, 1.05rem);
  font-weight: 600;
  letter-spacing: 0.18em;
}

.ia-avr__sub {
  margin-top: 0.3rem;
  color: rgba(201, 169, 110, 0.5);
  font-size: 0.6rem;
  letter-spacing: 0.22em;
}

.ia-avr__trigger {
  position: relative;
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  cursor: pointer;
  font: inherit;
  text-align: left;
}

/* Affordance: without this the faces look inert to a pointer user, and the
   collapsed units read as broken rather than closed. */
.ia-avr.is-enhanced .ia-avr__trigger::after {
  content: '+';
  position: absolute;
  top: 0.55rem;
  right: 0.6rem;
  color: var(--bronze-dim);
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1;
}

.ia-avr.is-enhanced .ia-avr__unit.is-active .ia-avr__trigger::after {
  content: '\2212';
}

.ia-avr.is-enhanced .ia-avr__trigger:hover .ia-avr__panel {
  border-color: var(--ia-line-strong);
}

.ia-avr.is-enhanced .ia-avr__unit {
  transition: border-color 0.25s var(--ease-out);
}

.ia-avr.is-enhanced .ia-avr__unit:not(.is-active) .ia-avr__read {
  display: none;
}

.ia-avr.is-enhanced .ia-avr__unit.is-active {
  border-color: var(--bronze-dim);
}

.ia-avr.is-enhanced .ia-avr__unit.is-active .ia-avr__panel {
  border-color: rgba(201, 169, 110, 0.45);
}

.ia-avr__read .ia-fact {
  grid-template-columns: minmax(0, 5rem) minmax(0, 1fr);
  padding: 0.45rem 0;
}

.ia-avr__read dd {
  font-size: 0.8rem;
}

/* ── Chapter E — diagnostic flow ──────────────────────────── */

.ia-flow__group {
  margin: clamp(1.75rem, 3vw, 2.5rem) 0 0.25rem;
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: var(--ia-micro);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.ia-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(1.75rem, 3vw, 2.5rem) 0 clamp(2.25rem, 4vw, 3rem);
  padding: 0;
  list-style: none;
  counter-reset: ia-step;
}

/* The second half continues the single ten-step sequence the copy promises. */
.ia-flow--second {
  counter-reset: ia-step 5;
}

.ia-flow__step {
  position: relative;
  counter-increment: ia-step;
  padding: 1.15rem 0 1.15rem 3.4rem;
  border-top: 1px solid rgba(201, 169, 110, 0.1);
}

.ia-flow__step::before {
  content: counter(ia-step, decimal-leading-zero);
  position: absolute;
  top: 1.2rem;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--ia-line-strong);
  border-radius: 50%;
  background: var(--ia-inset);
  color: var(--bronze);
  font-family: var(--font-body);
  font-size: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.06em;
}

/* The spine linking the ten checks into one flow. */
.ia-flow__step::after {
  content: '';
  position: absolute;
  top: 3.5rem;
  bottom: -0.2rem;
  left: 1.1rem;
  width: 1px;
  background: rgba(201, 169, 110, 0.16);
}

.ia-flow__step:last-child::after {
  display: none;
}

.ia-flow__question {
  margin: 0 0 0.3rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 2.1vw, 1.35rem);
  font-weight: 400;
  line-height: 1.3;
}

.ia-flow__step p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.86rem;
  line-height: 1.55;
}

/* ── FAQ as native disclosure ─────────────────────────────── */

.ia-faq {
  margin-top: clamp(2.25rem, 4vw, 3rem);
}

.ia-faq .faq-item {
  padding: 0;
  border-top: 1px solid rgba(201, 169, 110, 0.1);
}

.ia-faq summary {
  padding: 1.1rem 2rem 1.1rem 0;
  position: relative;
  color: var(--text-primary);
  cursor: pointer;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  line-height: 1.35;
  list-style: none;
}

.ia-faq summary::-webkit-details-marker {
  display: none;
}

.ia-faq summary::after {
  content: '+';
  position: absolute;
  top: 1rem;
  right: 0.2rem;
  color: var(--bronze-dim);
  font-family: var(--font-body);
  font-size: 1.1rem;
}

.ia-faq details[open] summary::after {
  content: '−';
}

.ia-faq details p {
  margin: 0;
  padding: 0 0 1.2rem;
  max-width: 68ch;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.65;
}

/* ── Breakpoints ──────────────────────────────────────────── */

@media (min-width: 861px) {
  .ia-compare.is-enhanced {
    display: grid;
    grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
    gap: clamp(1.5rem, 3vw, 2.5rem);
    align-items: start;
  }

  .ia-compare.is-enhanced .ia-rail--formats {
    flex-direction: column;
    margin: 0;
    overflow: visible;
  }

  .ia-compare.is-enhanced .ia-rail--formats .ia-rail__item {
    border-radius: 6px;
    text-align: left;
    white-space: normal;
  }

  .ia-explorer {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  /* Desktop has no drag affordance, so the explorer rails must show every
     option rather than scroll the last ones out of the column. */
  .ia-rail--source,
  .ia-rail--path {
    flex-wrap: wrap;
    overflow-x: visible;
  }

  .ia-rail--source .ia-rail__item,
  .ia-rail--path .ia-rail__item {
    white-space: normal;
  }

  .ia-explorer > .ia-verdict {
    grid-column: 1 / -1;
  }

  .ia-duo {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ia-avr__gallery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ia-dives {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1200px) {
  .ia-avr__gallery {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .ia-avr__read .ia-fact {
    grid-template-columns: minmax(0, 4.5rem) minmax(0, 1fr);
  }
}

/* Matches the shared hero breakpoint, where the two-column grid collapses. */
@media (max-width: 980px) {
  .ia-stack {
    margin-top: 2.25rem;
  }
}

@media (max-width: 860px) {
  .ia-fact {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.2rem;
  }

  .ia-facts--compact .ia-fact,
  .ia-avr__read .ia-fact {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 420px) {
  .ia-status,
  .ia-diagram__node {
    font-size: 0.7rem;
  }

  .ia-stack__stage {
    padding-left: 2rem;
  }

  .ia-diagram__node {
    flex: 1 1 100%;
  }

  .ia-diagram__node + .ia-diagram__node::before {
    content: '↓';
    top: -0.3rem;
    left: 50%;
  }

  .ia-flow__step {
    padding-left: 2.9rem;
  }
}

/* ── Reduced motion ───────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  .immersive-audio-guide .ia-example__button,
  .immersive-audio-guide .ia-rail__item,
  .immersive-audio-guide .ia-dive,
  .immersive-audio-guide .ia-card {
    transition: none;
  }

  .ia-stack.is-enhanced .ia-example__button.is-active {
    transform: none;
  }
}