:root {
  --void: #030508;
  /* hyper-carbon deep void */
  --panel: #060a10;
  /* raised carbon surface */
  --silver: #e2e8f0;
  /* cold silver text */
  --dim: rgba(226, 232, 240, 0.48);
  --faint: rgba(226, 232, 240, 0.22);
  --line: rgba(226, 232, 240, 0.1);
  --cyan: #05DF72;
  /* neon cyan telemetry */
  --cyan-soft: rgba(0, 240, 255, 0.1);
  --cyan-glass: rgba(0, 240, 255, 0.05);
  --red: #ff003c;
  /* laser red micro interactions */
  --disp: "Space Grotesk", sans-serif;
  --body: "Inter", sans-serif;
  --ease-silk: cubic-bezier(0.22, 1, 0.36, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  overflow: hidden;
  /* virtual scroll engine owns the page */
  overscroll-behavior: none;
}

body {
  background: var(--void);
  color: var(--silver);
  font-family: var(--body);
  font-weight: 300;
  -webkit-font-smoothing: antialiased;
}

/* faint engineering grid behind everything */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    repeating-linear-gradient(
      to right,
      rgba(226, 232, 240, 0.025) 0 1px,
      transparent 1px 120px
    ),
    repeating-linear-gradient(
      to bottom,
      rgba(226, 232, 240, 0.02) 0 1px,
      transparent 1px 120px
    );
  pointer-events: none;
  z-index: 0;
}

::selection {
  background: var(--cyan);
  color: var(--void);
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  background: none;
  border: 0;
  color: inherit;
  cursor: pointer;
}

button:focus-visible,
a:focus-visible {
  outline: 1px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------------------------------------------------------- */
/* STAGE AND TRACK PANELS                                      */
/* ---------------------------------------------------------- */

.stage {
  position: relative;
  z-index: 1;
}

.panel {
  position: fixed;
  top: 0;
  height: 100vh;
  width: 50%;
  display: flex;
  align-items: center;
  will-change: transform;
}

.t-left {
  left: 0;
}

.t-right {
  left: 50%;
}

.panel-inner {
  width: 100%;
  padding: 110px clamp(36px, 5vw, 84px);
}

/* center seam */
.seam {
  position: fixed;
  top: 0;
  left: 50%;
  width: 1px;
  height: 100vh;
  background: var(--line);
  z-index: 4;
  pointer-events: none;
}

.seam::after {
  content: "";
  position: absolute;
  left: -2px;
  top: 0;
  width: 5px;
  height: 56px;
  background: var(--cyan);
  opacity: 0.9;
  transform: translateY(0);
}

/* full-bleed media panels */
.panel-media {
  padding: 0;
  align-items: stretch;
}

.media-frame {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: grayscale(0.55) contrast(1.12) brightness(0.78);
}

/* cyan duotone wash to unify photography with the HUD */
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    160deg,
    rgba(0, 240, 255, 0.1),
    rgba(3, 5, 8, 0.55) 70%
  );
  mix-blend-mode: screen;
  pointer-events: none;
}

.media-tag {
  position: absolute;
  left: 28px;
  bottom: 26px;
  z-index: 2;
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--silver);
  background: rgba(3, 5, 8, 0.6);
  border: 1px solid var(--line);
  padding: 10px 14px;
  backdrop-filter: blur(4px);
}

.media-tag b {
  color: var(--cyan);
  font-weight: 500;
}

/* infinite scan line on the hero image */
.scanline {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--cyan);
  box-shadow:
    0 0 14px rgba(0, 240, 255, 0.9),
    0 0 40px rgba(0, 240, 255, 0.35);
  z-index: 2;
  animation: scanY 6s linear infinite;
}

@keyframes scanY {
  0% {
    top: -2px;
  }

  50% {
    top: 100%;
  }

  100% {
    top: -2px;
  }
}

/* ---------------------------------------------------------- */
/* SHARED TYPE PARTS                                           */
/* ---------------------------------------------------------- */

.eyebrow {
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--disp);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.34em;
  color: var(--cyan);
  margin-bottom: 30px;
}

.eyebrow::before {
  content: "";
  width: 34px;
  height: 1px;
  background: var(--cyan);
}

.lede {
  color: var(--dim);
  font-size: 14px;
  line-height: 1.85;
  letter-spacing: 0.02em;
  max-width: 46ch;
}

/* ---------------------------------------------------------- */
/* BLOCK 1 // TELEMETRY HERO                                   */
/* ---------------------------------------------------------- */

.hero-title {
  font-family: var(--disp);
  font-weight: 700;
  font-size: clamp(3.4rem, 6.4vw, 6.6rem);
  line-height: 0.94;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin-bottom: 34px;
}

.hero-title .slash {
  color: var(--cyan);
}

.hero-title .thin {
  font-weight: 400;
  color: var(--dim);
}

.clock-shell {
  display: inline-flex;
  align-items: baseline;
  gap: 16px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  padding: 16px 22px;
  margin: 38px 0 44px;
  background: rgba(6, 10, 16, 0.7);
}

.clock-label {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.3em;
  color: var(--dim);
}

#live-clock {
  font-family: var(--disp);
  font-weight: 500;
  font-size: clamp(1.3rem, 2vw, 1.8rem);
  letter-spacing: 0.08em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  min-width: 11ch;
}

#live-clock .ms {
  color: var(--red);
}

.spec-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-top: 1px solid var(--line);
}

.spec-cell {
  flex: 1 1 0;
  min-width: 120px;
  padding: 18px 18px 0 0;
  border-right: 1px solid var(--line);
  margin-right: 18px;
}

.spec-cell:last-child {
  border-right: 0;
  margin-right: 0;
}

.spec-cell .k {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.26em;
  color: var(--faint);
  display: block;
  margin-bottom: 8px;
}

.spec-cell .v {
  font-family: var(--disp);
  font-weight: 500;
  font-size: 1.25rem;
  color: var(--silver);
}

.spec-cell .v small {
  font-size: 0.7em;
  color: var(--cyan);
  margin-left: 4px;
}

/* ---------------------------------------------------------- */
/* BLOCK 2 // BLUEPRINT ACCORDION                              */
/* ---------------------------------------------------------- */

.section-title {
  font-family: var(--disp);
  font-weight: 700;
  font-size: clamp(2rem, 3.2vw, 3.2rem);
  line-height: 1.02;
  text-transform: uppercase;
  letter-spacing: -0.01em;
  margin-bottom: 18px;
}

.section-title .slash {
  color: var(--cyan);
}

.accordion {
  margin-top: 38px;
  border-top: 1px solid var(--line);
}

.acc-item {
  border: 1px solid transparent;
  border-bottom: 1px solid var(--line);
  transition:
    border-color 0.35s var(--ease-silk),
    background 0.35s var(--ease-silk);
}

.acc-item.open {
  border: 1px solid var(--cyan);
  background: var(--cyan-glass);
}

.acc-head {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 20px;
  text-align: left;
  padding: 22px 18px;
}

.acc-index {
  font-family: var(--disp);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--faint);
  transition: color 0.3s;
}

.acc-item.open .acc-index {
  color: var(--red);
}

.acc-title {
  flex: 1;
  font-family: var(--disp);
  font-weight: 500;
  font-size: 1.05rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.acc-icon {
  position: relative;
  width: 14px;
  height: 14px;
  flex: 0 0 14px;
}

.acc-icon::before,
.acc-icon::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition:
    transform 0.4s var(--ease-silk),
    background 0.3s;
}

.acc-icon::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.acc-icon::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
}

.acc-item.open .acc-icon::after {
  transform: scaleY(0);
}

.acc-item.open .acc-icon::before {
  background: var(--red);
}

.acc-head:hover .acc-title {
  color: var(--cyan);
}

.acc-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.55s var(--ease-silk);
}

.acc-body p {
  padding: 0 18px 24px 51px;
  color: var(--dim);
  font-size: 13.5px;
  line-height: 1.85;
}

.acc-body .data-strip {
  display: flex;
  gap: 26px;
  padding: 0 18px 22px 51px;
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

/* blueprint photo panel - image, marker and data react to the accordion */
.bp-stage {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--panel);
}

.bp-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.8s var(--ease-silk);
  filter: grayscale(0.55) contrast(1.12) brightness(0.75);
}

.bp-img.active {
  opacity: 1;
}

/* same cyan duotone wash as the other media panels */
.bp-stage::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    160deg,
    rgba(0, 240, 255, 0.1),
    rgba(3, 5, 8, 0.55) 70%
  );
  mix-blend-mode: screen;
  pointer-events: none;
  z-index: 1;
}

.bp-chip {
  position: absolute;
  top: 26px;
  left: 28px;
  z-index: 3;
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--silver);
  background: rgba(3, 5, 8, 0.6);
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  padding: 10px 14px;
  backdrop-filter: blur(4px);
}

/* target marker - repositions per accordion item */
.bp-marker {
  position: absolute;
  z-index: 3;
  left: 24%;
  top: 28%;
  transition:
    left 0.8s var(--ease-silk),
    top 0.8s var(--ease-silk);
}

.bp-ring {
  display: block;
  width: 16px;
  height: 16px;
  border: 1.5px solid var(--cyan);
  border-radius: 50%;
  box-shadow: 0 0 14px rgba(0, 240, 255, 0.7);
  position: relative;
  transition: border-color 0.2s;
}

/* expanding sonar pulse */
.bp-ring::after {
  content: "";
  position: absolute;
  inset: -1.5px;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  animation: bpPulse 2.2s ease-out infinite;
}

@keyframes bpPulse {
  0% {
    transform: scale(1);
    opacity: 0.9;
  }

  100% {
    transform: scale(3.2);
    opacity: 0;
  }
}

.bp-hairline {
  position: absolute;
  left: 22px;
  top: 7.5px;
  width: 72px;
  height: 1px;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(0, 240, 255, 0.5);
}

.bp-data {
  position: absolute;
  left: 102px;
  top: -10px;
  white-space: nowrap;
  font-family: var(--disp);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--cyan);
  background: rgba(3, 5, 8, 0.7);
  border: 1px solid rgba(0, 240, 255, 0.35);
  padding: 8px 12px;
  backdrop-filter: blur(4px);
}

/* laser red blip on change */
.bp-marker.blip .bp-ring {
  border-color: var(--red);
  box-shadow: 0 0 14px rgba(255, 0, 60, 0.8);
}

.bp-marker.blip .bp-hairline {
  background: var(--red);
}

/* ---------------------------------------------------------- */
/* BLOCK 3 // 3D KINETIC CAROUSEL                              */
/* ---------------------------------------------------------- */

.carousel-panel {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 30px;
  padding-top: 90px;
  padding-bottom: 80px;
}

.c3d-stage {
  width: 100%;
  height: 330px;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 1000px;
  cursor: grab;
  touch-action: pan-y;
  user-select: none;
  -webkit-user-select: none;
}

.c3d-stage.dragging {
  cursor: grabbing;
}

.c3d {
  position: relative;
  width: 230px;
  height: 300px;
  transform-style: preserve-3d;
}

.c3d-card {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  transition: opacity 0.2s linear;
}

/* two-sided cards: designed back face instead of mirrored text */
.card-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 22px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.face-front {
  background: var(--cyan-glass);
  border: 1px solid var(--cyan);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  box-shadow: 0 0 50px rgba(0, 240, 255, 0.06) inset;
}

.face-back {
  transform: rotateY(180deg);
  align-items: center;
  justify-content: center;
  gap: 16px;
  background: rgba(6, 10, 16, 0.88);
  border: 1px dashed rgba(0, 240, 255, 0.35);
}

.face-back .back-id {
  font-family: var(--disp);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.34em;
  color: var(--cyan);
}

.face-back .back-bars {
  width: 90px;
  height: 30px;
  background: repeating-linear-gradient(
    to right,
    rgba(0, 240, 255, 0.55) 0 2px,
    transparent 2px 6px,
    rgba(0, 240, 255, 0.3) 6px 7px,
    transparent 7px 12px
  );
}

.face-back .back-label {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.3em;
  color: var(--faint);
}

.c3d-card .c-id {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.3em;
  color: var(--red);
}

.c3d-card .c-name {
  font-family: var(--disp);
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.c3d-card .c-fig {
  font-family: var(--disp);
  font-weight: 500;
  font-size: 2rem;
  color: var(--cyan);
}

.c3d-card .c-fig small {
  font-size: 0.5em;
  color: var(--dim);
  margin-left: 4px;
}

.c3d-card .c-desc {
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--dim);
}

/* control deck */
.c3d-deck {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.c3d-status {
  font-family: var(--disp);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.28em;
  color: var(--silver);
}

.c3d-status b {
  color: var(--cyan);
  font-weight: 500;
}

.c3d-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.c3d-ctl,
.mod-btn {
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  background: rgba(6, 10, 16, 0.7);
  transition:
    border-color 0.25s,
    color 0.25s,
    background 0.25s;
}

.c3d-ctl {
  width: 42px;
}

.c3d-ctl:hover {
  border-color: var(--red);
}

.chev-l,
.chev-r {
  width: 9px;
  height: 9px;
  border-left: 1.6px solid var(--cyan);
  border-bottom: 1.6px solid var(--cyan);
  transition: border-color 0.25s;
}

.chev-l {
  transform: rotate(45deg) translate(1px, -1px);
}

.chev-r {
  transform: rotate(-135deg) translate(1px, -1px);
}

.c3d-ctl:hover .chev-l,
.c3d-ctl:hover .chev-r {
  border-color: var(--red);
}

.mod-btn {
  min-width: 42px;
  padding: 0 10px;
  font-family: var(--disp);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--dim);
}

.mod-btn:hover {
  color: var(--silver);
  border-color: rgba(226, 232, 240, 0.3);
}

.mod-btn.active {
  color: var(--red);
  border-color: var(--red);
}

/* play and pause glyphs drawn in CSS */
.ico-play {
  width: 0;
  height: 0;
  border-left: 9px solid var(--cyan);
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
}

.c3d-ctl.playing .ico-play {
  width: 8px;
  height: 12px;
  border-top: 0;
  border-bottom: 0;
  border-left: 3px solid var(--cyan);
  border-right: 3px solid var(--cyan);
}

.c3d-hint {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.3em;
  color: var(--faint);
}

.c3d-hint b {
  color: var(--cyan);
  font-weight: 500;
}

/* ---------------------------------------------------------- */
/* BLOCK 4 // SYSTEM TABS AND KINETIC TYPE                     */
/* ---------------------------------------------------------- */

.tab-rail {
  display: flex;
  border: 1px solid var(--line);
  margin: 40px 0 30px;
}

.tab-btn {
  flex: 1;
  padding: 18px 10px;
  font-family: var(--disp);
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--dim);
  border-right: 1px solid var(--line);
  position: relative;
  transition:
    color 0.2s,
    background 0.2s;
}

.tab-btn:last-child {
  border-right: 0;
}

.tab-btn::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease-silk);
}

.tab-btn:hover {
  color: var(--silver);
  background: rgba(226, 232, 240, 0.03);
}

.tab-btn.active {
  color: var(--red);
}

.tab-btn.active::after {
  transform: scaleX(1);
}

.tab-copy {
  min-height: 96px;
}

.tab-copy p {
  color: var(--dim);
  font-size: 13.5px;
  line-height: 1.85;
  max-width: 44ch;
}

.tab-meta {
  margin-top: 26px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.tab-chip {
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  border: 1px solid rgba(0, 240, 255, 0.35);
  padding: 8px 14px;
}

.promo-line {
  margin-top: 46px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--faint);
}

.promo-line a {
  color: var(--dim);
  border-bottom: 1px solid var(--faint);
  transition:
    color 0.2s,
    border-color 0.2s;
}

.promo-line a:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}

/* kinetic outline typography */
.kinetic-panel {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  padding: 0 clamp(30px, 4vw, 70px);
  overflow: hidden;
  background: radial-gradient(
    circle at 30% 70%,
    rgba(255, 0, 60, 0.05),
    transparent 55%
  );
}

.kinetic-label {
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.34em;
  color: var(--red);
  margin-bottom: 22px;
}

.kinetic-value {
  font-family: var(--disp);
  font-weight: 700;
  font-size: clamp(3.4rem, 8vw, 9rem);
  line-height: 0.92;
  text-transform: uppercase;
  letter-spacing: -0.01em;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--cyan);
  transition:
    opacity 0.18s ease,
    transform 0.18s ease,
    letter-spacing 0.18s ease;
  word-break: break-word;
}

.kinetic-value.swap {
  opacity: 0;
  transform: translateY(14px);
  letter-spacing: 0.06em;
}

.kinetic-sub {
  margin-top: 26px;
  font-family: var(--disp);
  font-size: 12px;
  letter-spacing: 0.26em;
  color: var(--dim);
}

.kinetic-sub b {
  color: var(--silver);
  font-weight: 500;
}

/* ---------------------------------------------------------- */
/* THE HUD OVERLAY                                             */
/* ---------------------------------------------------------- */

.hud {
  position: fixed;
  inset: 0;
  z-index: 20;
  pointer-events: none;
}

.hud-frame {
  position: absolute;
  inset: 14px;
  border: 1px solid var(--line);
}

/* corner brackets */
.hud-frame::before,
.hud-frame::after,
.hud-frame .ck::before,
.hud-frame .ck::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--cyan);
  border-style: solid;
}

.hud-frame::before {
  top: -1px;
  left: -1px;
  border-width: 2px 0 0 2px;
}

.hud-frame::after {
  top: -1px;
  right: -1px;
  border-width: 2px 2px 0 0;
}

.hud-frame .ck::before {
  bottom: -1px;
  left: -1px;
  border-width: 0 0 2px 2px;
}

.hud-frame .ck::after {
  bottom: -1px;
  right: -1px;
  border-width: 0 2px 2px 0;
}

.hud-item {
  position: absolute;
  pointer-events: auto;
}

.hud-brand {
  top: 30px;
  left: 38px;
  font-family: var(--disp);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.3em;
}

.hud-brand .slash {
  color: var(--cyan);
}

.hud-index {
  top: 32px;
  right: 38px;
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--dim);
  font-variant-numeric: tabular-nums;
}

.hud-index b {
  color: var(--cyan);
  font-weight: 500;
}

.hud-credit {
  bottom: 30px;
  left: 38px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--disp);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--dim);
}

.hud-credit a {
  color: var(--silver);
  transition: color 0.2s;
}

.hud-credit a:hover {
  color: var(--cyan);
}

.hud-credit .dot {
  width: 5px;
  height: 5px;
  background: var(--cyan);
}

.hud-progress {
  bottom: 30px;
  right: 38px;
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--disp);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.hud-progress .bar {
  width: 90px;
  height: 2px;
  background: var(--line);
  position: relative;
  overflow: hidden;
}

.hud-progress .bar i {
  position: absolute;
  inset: 0;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
}

.hud-hint {
  bottom: 88px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--disp);
  font-size: 10px;
  letter-spacing: 0.34em;
  color: var(--faint);
  animation: hintPulse 2.6s ease-in-out infinite;
  transition: opacity 0.6s ease;
}

.hud-hint.hide {
  opacity: 0 !important;
  animation: none;
}

/* arrow nav - bottom center, split by the seam */
.hud-arrows {
  bottom: 26px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 1px;
}

.arrow-btn {
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  background: rgba(6, 10, 16, 0.78);
  backdrop-filter: blur(4px);
  transition:
    border-color 0.25s,
    background 0.25s,
    opacity 0.25s;
}

.arrow-btn .chev {
  width: 11px;
  height: 11px;
  border-left: 1.6px solid var(--cyan);
  border-bottom: 1.6px solid var(--cyan);
  transition:
    border-color 0.25s,
    transform 0.25s var(--ease-silk);
}

.arrow-btn.up .chev {
  transform: rotate(135deg) translate(-2px, 2px);
}

.arrow-btn.down .chev {
  transform: rotate(-45deg) translate(2px, -2px);
}

.arrow-btn:hover {
  border-color: var(--red);
  background: rgba(255, 0, 60, 0.06);
}

.arrow-btn:hover .chev {
  border-color: var(--red);
}

.arrow-btn.up:hover .chev {
  transform: rotate(135deg) translate(0, 0);
}

.arrow-btn.down:hover .chev {
  transform: rotate(-45deg) translate(0, 0);
}

.arrow-btn[disabled] {
  opacity: 0.25;
  pointer-events: none;
}

@keyframes hintPulse {
  0%,
  100% {
    opacity: 0.35;
  }

  50% {
    opacity: 1;
  }
}

/* ---------------------------------------------------------- */
/* REVEALS                                                     */
/* ---------------------------------------------------------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition:
    opacity 0.9s var(--ease-silk),
    transform 0.9s var(--ease-silk);
}

.reveal.on {
  opacity: 1;
  transform: translateY(0);
}

/* ---------------------------------------------------------- */
/* REDUCED MOTION                                              */
/* ---------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .scanline {
    animation: none;
    top: 40%;
  }

  .hud-hint {
    animation: none;
    opacity: 0.6;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .acc-body {
    transition: none;
  }

  .kinetic-value {
    transition: none;
  }

  .bp-img {
    transition: none;
  }

  .bp-marker {
    transition: none;
  }

  .bp-ring::after {
    animation: none;
    opacity: 0;
  }
}

/* ---------------------------------------------------------- */
/* MOBILE AND NARROW LAYOUT - native scroll fallback           */
/* ---------------------------------------------------------- */

@media (max-width: 900px) {
  html,
  body {
    overflow: visible;
    overflow-y: auto;
    overscroll-behavior: auto;
  }

  .panel {
    position: static;
    width: 100%;
    height: auto;
    min-height: 0;
    transform: none !important;
    will-change: auto;
  }

  .panel-inner {
    padding: 86px 26px;
  }

  .panel-media {
    height: 64vh;
    min-height: 380px;
  }

  .kinetic-panel {
    min-height: 60vh;
    padding: 70px 26px;
  }

  .seam {
    display: none;
  }

  .hud-frame,
  .hud-index,
  .hud-hint,
  .hud-arrows {
    display: none;
  }

  .hud-brand {
    top: 20px;
    left: 22px;
    mix-blend-mode: difference;
  }

  .hud-credit {
    bottom: auto;
    top: 20px;
    right: 22px;
    left: auto;
  }

  .hud-progress {
    display: none;
  }

  .c3d-stage {
    height: 340px;
  }

  .spec-cell {
    flex: 1 1 40%;
    margin-bottom: 18px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2.9rem;
  }

  .kinetic-value {
    font-size: 2.6rem;
    -webkit-text-stroke-width: 1px;
  }

  .tab-btn {
    letter-spacing: 0.12em;
    font-size: 10.5px;
  }
}