/*
 * CARSPARE engine-system hero
 * Brand source: docs/brand/00-Apex-Auto-VI系统与设计规范.md
 * All colors resolve to APEX VI tokens. SVG stays transparent for banner reuse.
 */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--apx-charcoal-900);
  scroll-behavior: smooth;
}

body {
  display: grid;
  min-height: 100vh;
  min-height: 100svh;
  place-items: center;
  margin: 0;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 78% 48%, var(--apx-forest-900), transparent 42%),
    var(--apx-charcoal-900);
  color: var(--apx-on-dark);
  font-family: var(--apx-font-sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

button,
a {
  font: inherit;
}

a {
  color: inherit;
}

::selection {
  background: var(--apx-forest-300);
  color: var(--apx-charcoal-950);
}

/* Banner shell: 16:9 at desktop, natural height on small screens. */
.banner-frame {
  position: relative;
  isolation: isolate;
  display: grid;
  width: min(100%, 1600px);
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  background: var(--apx-charcoal-900);
  color: var(--apx-on-dark);
}

.banner-frame::before,
.banner-frame::after {
  position: absolute;
  z-index: -1;
  content: "";
  pointer-events: none;
}

.banner-frame::before {
  inset: 0;
  background-image:
    radial-gradient(circle, var(--apx-slate-300) 0.8px, transparent 0.9px),
    linear-gradient(to right, var(--apx-slate-300) 1px, transparent 1px),
    linear-gradient(to bottom, var(--apx-slate-300) 1px, transparent 1px);
  background-position: -1px -1px, 0 0, 0 0;
  background-size: 24px 24px, 96px 96px, 96px 96px;
  opacity: 0.045;
  -webkit-mask-image: linear-gradient(to right, transparent 2%, black 24%, black 100%);
  mask-image: linear-gradient(to right, transparent 2%, black 24%, black 100%);
}

.banner-frame::after {
  top: 18%;
  right: -8%;
  width: 56%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, var(--apx-forest-500), transparent 68%);
  opacity: 0.07;
  filter: blur(10px);
}

.banner-document--transparent,
.banner-document--transparent body,
.banner-document--transparent .banner-frame {
  background: transparent;
}

/* Header */
.banner-nav {
  position: relative;
  z-index: 4;
  display: flex;
  min-height: 86px;
  align-items: center;
  gap: 32px;
  padding: 0 clamp(24px, 4vw, 60px);
  border-bottom: 1px solid var(--apx-charcoal-800);
}

.brand-lockup {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  text-decoration: none;
}

.brand-lockup picture {
  display: flex;
}

.brand-lockup img {
  display: block;
  width: auto;
  height: 46px;
}

.banner-nav__links {
  display: flex;
  align-items: center;
  gap: clamp(18px, 2.2vw, 34px);
  margin-right: auto;
}

.banner-nav__links a {
  position: relative;
  padding: 10px 0;
  color: var(--apx-on-dark-muted);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  transition: color var(--apx-duration-fast) var(--apx-ease-standard);
}

.banner-nav__links a::after {
  position: absolute;
  right: 0;
  bottom: 4px;
  left: 0;
  height: 1px;
  background: var(--apx-forest-300);
  content: "";
  opacity: 0;
  transform: scaleX(0);
  transform-origin: right;
  transition:
    opacity var(--apx-duration-fast) var(--apx-ease-standard),
    transform var(--apx-duration-base) var(--apx-ease-standard);
}

.banner-nav__links a:hover {
  color: var(--apx-white);
}

.banner-nav__links a:hover::after {
  opacity: 1;
  transform: scaleX(1);
  transform-origin: left;
}

.nav-cta {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 14px;
  padding: 0 18px;
  border: 1px solid var(--apx-charcoal-800);
  border-radius: var(--apx-radius-action);
  background: var(--apx-forest-600);
  color: var(--apx-white);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  transition:
    background-color var(--apx-duration-fast) var(--apx-ease-standard),
    border-color var(--apx-duration-fast) var(--apx-ease-standard);
}

.nav-cta:hover {
  border-color: var(--apx-forest-500);
  background: var(--apx-forest-700);
}

.nav-cta__arrow {
  font-family: var(--apx-font-mono);
  font-size: 15px;
  transition: transform var(--apx-duration-fast) var(--apx-ease-standard);
}

.nav-cta:hover .nav-cta__arrow {
  transform: translate(2px, -2px);
}

/* Main composition */
.banner-content {
  display: grid;
  min-height: 0;
  grid-template-columns: minmax(0, 0.75fr) minmax(0, 1.25fr);
  align-items: center;
  gap: clamp(16px, 2vw, 36px);
  padding: clamp(28px, 3.1vw, 48px) clamp(24px, 4vw, 60px) clamp(16px, 2.1vw, 32px);
}

.banner-copy {
  position: relative;
  z-index: 2;
  max-width: 580px;
  padding-block: clamp(8px, 1.3vw, 20px);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 24px;
  color: var(--apx-forest-300);
  font-family: var(--apx-font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.11em;
  line-height: 1.4;
  text-transform: uppercase;
}

.eyebrow__rule {
  width: 32px;
  height: 1px;
  background: var(--apx-forest-500);
}

.banner-copy h1 {
  max-width: 620px;
  margin: 0;
  color: var(--apx-on-dark);
  font-size: clamp(44px, 4.4vw, 60px);
  font-weight: 700;
  letter-spacing: -0.038em;
  line-height: 1.02;
}

.banner-copy h1 span {
  color: var(--apx-forest-300);
}

.banner-lede {
  max-width: 46ch;
  margin: 26px 0 0;
  color: var(--apx-on-dark-muted);
  font-size: clamp(14px, 1.15vw, 16px);
  line-height: 1.72;
}

.banner-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.cta {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--apx-radius-action);
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  transition:
    background-color var(--apx-duration-fast) var(--apx-ease-standard),
    border-color var(--apx-duration-fast) var(--apx-ease-standard),
    color var(--apx-duration-fast) var(--apx-ease-standard),
    transform var(--apx-duration-fast) var(--apx-ease-standard);
}

.cta:hover {
  transform: translateY(-1px);
}

.cta--primary {
  min-width: 190px;
  background: var(--apx-forest-600);
  color: var(--apx-white);
}

.cta--primary:hover {
  background: var(--apx-forest-700);
}

.cta--secondary {
  min-width: 214px;
  border-color: var(--apx-charcoal-800);
  background: transparent;
  color: var(--apx-on-dark);
}

.cta--secondary:hover {
  border-color: var(--apx-slate-500);
  background: var(--apx-charcoal-950);
}

.cta__mark {
  display: grid;
  width: 26px;
  height: 22px;
  place-items: center;
  border: 1px solid var(--apx-charcoal-800);
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 9px;
  letter-spacing: 0.04em;
}

.proof-strip {
  display: grid;
  max-width: 540px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  margin: clamp(34px, 4vw, 58px) 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--apx-charcoal-800);
}

.proof-strip div {
  min-width: 0;
  padding-right: 16px;
}

.proof-strip div + div {
  padding-left: 20px;
  border-left: 1px solid var(--apx-charcoal-800);
}

.proof-strip dt {
  margin: 0 0 5px;
  color: var(--apx-forest-300);
  font-family: var(--apx-font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  line-height: 1.4;
  text-transform: uppercase;
}

.proof-strip dd {
  margin: 0;
  color: var(--apx-on-dark-muted);
  font-size: 11px;
  line-height: 1.5;
}

/* Engine stage */
.engine-stage {
  position: relative;
  display: flex;
  min-width: 0;
  min-height: 0;
  flex-direction: column;
  align-self: stretch;
  padding-left: clamp(8px, 1.4vw, 24px);
}

.engine-stage::before {
  position: absolute;
  top: 4%;
  right: 7%;
  bottom: 10%;
  left: 14%;
  border: 1px solid var(--apx-charcoal-800);
  border-radius: 50%;
  content: "";
  opacity: 0.28;
  pointer-events: none;
  transform: rotate(-8deg);
}

.engine-stage__meta {
  position: relative;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 4px;
}

.tech-label {
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.09em;
  line-height: 1.4;
  text-transform: uppercase;
}

.cycle-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
}

.cycle-status__dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--apx-forest-300);
  box-shadow: 0 0 0 3px var(--apx-forest-900);
}

.engine-stage__drawing {
  position: relative;
  z-index: 1;
  display: flex;
  min-height: 0;
  flex: 1 1 0;
  align-items: center;
  justify-content: center;
  padding-top: 8px;
}

.engine-svg {
  --engine-stroke-strong: 1.8px;
  --engine-stroke-main: 1.25px;
  --engine-stroke-detail: 0.9px;
  display: block;
  width: 100%;
  height: 100%;
  overflow: visible;
  color: var(--apx-on-dark);
}

.engine-svg text {
  font-family: var(--apx-font-mono);
}

.engine-svg path,
.engine-svg circle {
  vector-effect: initial;
}

.technical-guides path,
.technical-guides circle {
  fill: none;
  stroke: var(--apx-slate-300);
  stroke-width: 1;
  stroke-opacity: 0.11;
}

.technical-guides path:nth-last-child(-n + 4) {
  stroke-dasharray: 2 5;
}

.engine-fill {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.65;
}

.engine-outline {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-width: var(--engine-stroke-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
}

.engine-line,
.cylinder-bore,
.port,
.camshaft-line,
.crank-axle__line,
.timing-cover__detail {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-linecap: round;
  stroke-linejoin: round;
}

.engine-line {
  stroke-width: var(--engine-stroke-main);
  stroke-opacity: 0.72;
}

.engine-detail,
.coolant-path,
.bolt-row circle,
.port-seat,
.timing-guide {
  fill: none;
  stroke: var(--apx-slate-300);
  stroke-linecap: round;
  stroke-linejoin: round;
}

.engine-detail {
  stroke-width: var(--engine-stroke-detail);
  stroke-opacity: 0.32;
}

.bolt-row circle {
  stroke-width: 1;
  stroke-opacity: 0.55;
}

.cylinder {
  opacity: 0.72;
  transition: opacity var(--apx-duration-slow) var(--apx-ease-standard);
}

.cylinder--primary {
  opacity: 1;
}

.cylinder-bore {
  stroke-width: 1.45;
  stroke-opacity: 0.92;
}

.cylinder-wall {
  stroke-dasharray: 3 5;
}

.coolant-path {
  stroke-width: 1.2;
  stroke-opacity: 0.2;
  stroke-dasharray: 2 7;
}

.port {
  stroke-width: 1.2;
  stroke-opacity: 0.4;
  transition:
    stroke var(--apx-duration-base) var(--apx-ease-standard),
    stroke-opacity var(--apx-duration-base) var(--apx-ease-standard);
}

.port-seat {
  stroke-width: 1;
  stroke-opacity: 0.42;
}

.cylinder[data-phase="intake"] .port--intake,
.cylinder[data-phase="exhaust"] .port--exhaust {
  stroke: var(--apx-forest-300);
  stroke-opacity: 1;
}

.gas-trace {
  fill: none;
  stroke: var(--apx-forest-300);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-dasharray: 3 7;
  stroke-opacity: 0;
  filter: drop-shadow(0 0 3px var(--apx-forest-600));
  transition: stroke-opacity 120ms var(--apx-ease-standard);
}

.compression-lines path {
  fill: none;
  stroke: var(--apx-forest-300);
  stroke-width: 0.9;
  stroke-linecap: round;
  stroke-opacity: 0;
}

.combustion-glow__core {
  stop-color: var(--apx-forest-200);
  stop-opacity: 0.72;
}

.combustion-glow__edge {
  stop-color: var(--apx-forest-500);
  stop-opacity: 0.28;
}

.combustion-glow__tail {
  stop-color: var(--apx-forest-900);
  stop-opacity: 0;
}

.cam-lobe path {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.7;
  stroke: var(--apx-on-dark);
  stroke-width: 1.25;
  stroke-linejoin: round;
}

.cam-lobe circle {
  fill: var(--apx-charcoal-900);
  stroke: var(--apx-on-dark-muted);
  stroke-width: 1;
}

.cylinder[data-phase="intake"] .cam-lobe--intake path,
.cylinder[data-phase="exhaust"] .cam-lobe--exhaust path {
  stroke: var(--apx-forest-300);
  stroke-opacity: 0.9;
}

.valve-stem,
.valve-head,
.valve-bucket {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-linecap: round;
  stroke-linejoin: round;
}

.valve-stem {
  stroke-width: 1.1;
  stroke-opacity: 0.9;
}

.valve-head {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.86;
  stroke-width: 1.2;
}

.valve-bucket {
  stroke-width: 2;
  stroke-opacity: 0.74;
}

.spark-plug__body {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.72;
  stroke: var(--apx-on-dark);
  stroke-width: 1.1;
}

.spark-plug__ribs,
.spark-plug__electrode {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-linecap: round;
}

.spark-plug__ribs {
  stroke-width: 0.8;
  stroke-opacity: 0.7;
}

.spark-plug__electrode {
  stroke-width: 1.2;
}

.spark__core {
  fill: var(--apx-forest-200);
}

.spark__rays {
  fill: none;
  stroke: var(--apx-forest-200);
  stroke-width: 1.4;
  stroke-linecap: round;
}

.spark__ring {
  fill: none;
  stroke: var(--apx-forest-300);
  stroke-width: 1;
}

.crank-arm__body {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.88;
  stroke: var(--apx-on-dark);
  stroke-width: 1.35;
  stroke-linejoin: round;
}

.crank-arm__weight {
  fill: var(--apx-slate-500);
  fill-opacity: 0.22;
  stroke: var(--apx-on-dark);
  stroke-width: 1.1;
  stroke-opacity: 0.8;
}

.crank-pin {
  fill: var(--apx-charcoal-950);
  stroke: var(--apx-on-dark);
  stroke-width: 1.4;
}

.rod__body {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.72;
  stroke: var(--apx-on-dark);
  stroke-width: 1.25;
  stroke-linejoin: round;
}

.rod__small,
.rod__big {
  fill: var(--apx-charcoal-900);
  stroke: var(--apx-on-dark);
  stroke-width: 1.35;
}

.rod__small {
  stroke: var(--apx-forest-300);
  stroke-opacity: 0.82;
}

.piston__body {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.92;
  stroke: var(--apx-on-dark);
  stroke-width: 1.45;
  stroke-linejoin: round;
}

.piston__crown {
  fill: var(--apx-slate-500);
  fill-opacity: 0.18;
  stroke: var(--apx-on-dark);
  stroke-width: 1;
}

.piston__rings {
  fill: none;
  stroke: var(--apx-forest-300);
  stroke-width: 0.9;
  stroke-opacity: 0.7;
}

.piston__pin {
  fill: var(--apx-charcoal-900);
  stroke: var(--apx-on-dark);
  stroke-width: 1.2;
}

.piston__pin-core {
  fill: var(--apx-on-dark);
  fill-opacity: 0.55;
}

.cylinder-index {
  fill: var(--apx-on-dark-muted);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.07em;
  opacity: 0.54;
  text-anchor: middle;
}

.cylinder--primary .cylinder-index {
  fill: var(--apx-forest-300);
  opacity: 0.9;
}

.cylinder-tick {
  fill: none;
  stroke: var(--apx-slate-300);
  stroke-width: 1;
  stroke-opacity: 0.24;
}

.camshaft-line {
  stroke-width: 2.1;
  stroke-opacity: 0.44;
}

.camshaft-line--exhaust {
  stroke-width: 1.1;
  stroke-opacity: 0.56;
}

.camshaft-node {
  fill: var(--apx-charcoal-900);
  stroke: var(--apx-on-dark-muted);
  stroke-width: 1;
  stroke-opacity: 0.7;
}

.crank-axle__line {
  stroke-width: 4;
  stroke-opacity: 0.5;
}

.crank-main {
  fill: var(--apx-charcoal-950);
  stroke: var(--apx-on-dark);
  stroke-width: 1.3;
}

.crank-bearing {
  fill: none;
  stroke: var(--apx-slate-300);
  stroke-width: 1;
  stroke-dasharray: 2 4;
  stroke-opacity: 0.35;
}

.timing-cover {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.34;
  stroke: var(--apx-slate-300);
  stroke-width: 1;
  stroke-opacity: 0.18;
}

.timing-cover__detail {
  stroke-width: 1;
  stroke-opacity: 0.16;
}

.timing-chain,
.timing-chain-motion {
  fill: none;
  stroke-linecap: round;
}

.timing-chain {
  stroke: var(--apx-slate-300);
  stroke-width: 3.2;
  stroke-opacity: 0.26;
}

.timing-chain-motion {
  stroke: var(--apx-forest-300);
  stroke-width: 1.5;
  stroke-opacity: 0.52;
  stroke-dasharray: 3 7;
}

.timing-sprocket circle:not(.timing-sprocket__bolt) {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-width: 1.3;
}

.timing-sprocket__teeth {
  stroke: var(--apx-forest-300);
  stroke-width: 1.2;
  stroke-opacity: 0.72;
  stroke-dasharray: 3 4;
}

.timing-sprocket__hub {
  fill: var(--apx-charcoal-950);
  fill-opacity: 0.9;
  stroke: var(--apx-on-dark-muted);
}

.timing-sprocket__spokes {
  fill: none;
  stroke: var(--apx-on-dark);
  stroke-width: 1.1;
  stroke-opacity: 0.64;
  stroke-linecap: round;
}

.timing-sprocket__bolt {
  fill: var(--apx-forest-300);
  fill-opacity: 0.74;
  stroke: none;
}

.timing-guide {
  stroke-width: 1;
  stroke-opacity: 0.24;
}

.engine-callouts path {
  fill: none;
  stroke: var(--apx-slate-300);
  stroke-width: 0.9;
  stroke-opacity: 0.22;
}

.engine-callouts text {
  fill: var(--apx-on-dark-muted);
  font-size: 8.5px;
  letter-spacing: 0.08em;
  opacity: 0.48;
}

/* Entry reveal */
.engine-draw {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw-engine 1.25s var(--apx-ease-standard) forwards;
}

.engine-base .engine-draw:nth-child(3) {
  animation-delay: 90ms;
}

.engine-base .engine-draw:nth-child(4) {
  animation-delay: 160ms;
}

.banner-copy,
.engine-stage__meta,
.engine-hud,
.banner-footer {
  animation: rise-in 560ms var(--apx-ease-standard) both;
}

.banner-copy {
  animation-delay: 60ms;
}

.engine-stage__meta {
  animation-delay: 160ms;
}

.engine-hud {
  animation-delay: 260ms;
}

.engine-svg {
  animation: engine-in 720ms 80ms var(--apx-ease-standard) both;
}

@keyframes draw-engine {
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes engine-in {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.985);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* Technical HUD */
.engine-hud {
  position: relative;
  z-index: 3;
  display: grid;
  grid-template-columns: minmax(116px, 0.78fr) minmax(220px, 1.45fr) minmax(170px, 1fr) auto;
  gap: 22px;
  align-items: end;
  padding: 14px 4px 2px;
  border-top: 1px solid var(--apx-charcoal-800);
}

.phase-readout__stage {
  display: block;
  min-width: 0;
  margin-top: 4px;
}

.phase-readout strong {
  display: block;
  color: var(--apx-forest-300);
  font-size: clamp(19px, 1.5vw, 23px);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1;
  text-transform: uppercase;
  white-space: nowrap;
}

.phase-readout__stage span {
  display: block;
  margin-top: 4px;
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.phase-progress__track {
  position: relative;
  height: 2px;
  overflow: hidden;
  background: var(--apx-charcoal-800);
}

.phase-progress__fill {
  position: absolute;
  inset: 0;
  background: var(--apx-forest-500);
  transform: scaleX(0);
  transform-origin: left;
  will-change: transform;
}

.phase-progress__marker {
  position: absolute;
  top: -2px;
  left: 0;
  width: 1px;
  height: 6px;
  background: var(--apx-forest-200);
  box-shadow: 0 0 0 2px var(--apx-forest-900);
  will-change: transform;
}

.phase-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin: 9px 0 0;
  padding: 0;
  list-style: none;
}

.phase-steps li {
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 10px;
  letter-spacing: 0.04em;
  line-height: 1.3;
  text-transform: uppercase;
  transition: color var(--apx-duration-base) var(--apx-ease-standard);
}

.phase-steps li span {
  margin-left: 3px;
}

.phase-steps li.is-active {
  color: var(--apx-forest-300);
}

.cylinder-phases__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 5px;
  margin-top: 7px;
}

.cylinder-phases__grid > span {
  display: grid;
  gap: 2px;
  padding-left: 6px;
  border-left: 1px solid var(--apx-charcoal-800);
  color: var(--apx-on-dark-muted);
  font-family: var(--apx-font-mono);
  font-size: 8.5px;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-transform: uppercase;
}

.cylinder-phases__grid b {
  color: var(--apx-on-dark);
  font-size: 9px;
  font-weight: 600;
}

.cylinder-phases__grid > span[data-phase="intake"],
.cylinder-phases__grid > span[data-phase="exhaust"],
.cylinder-phases__grid > span[data-phase="compression"],
.cylinder-phases__grid > span[data-phase="power"] {
  border-left-color: var(--apx-forest-500);
}

.crank-readout {
  min-width: 82px;
  text-align: right;
}

.crank-readout strong {
  display: block;
  margin-top: 3px;
  color: var(--apx-on-dark);
  font-family: var(--apx-font-mono);
  font-size: 22px;
  font-weight: 500;
  font-variant-numeric: tabular-nums lining-nums;
  letter-spacing: -0.02em;
  line-height: 1;
}

.crank-readout strong span:last-child {
  margin-left: 2px;
  color: var(--apx-forest-300);
  font-size: 11px;
}

/* Footer */
.banner-footer {
  display: flex;
  min-height: 58px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 clamp(24px, 4vw, 60px);
  border-top: 1px solid var(--apx-charcoal-800);
}

.banner-footer p {
  display: flex;
  align-items: center;
  gap: 20px;
  margin: 0;
  color: var(--apx-on-dark-muted);
  font-size: 11px;
  line-height: 1.5;
}

.footer-index {
  color: var(--apx-forest-300);
  font-family: var(--apx-font-mono);
  font-size: 9px;
  letter-spacing: 0.08em;
}

.banner-footer a {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--apx-on-dark);
  font-size: 11px;
  font-weight: 600;
  text-decoration: none;
}

.banner-footer a span {
  color: var(--apx-forest-300);
  font-family: var(--apx-font-mono);
  transition: transform var(--apx-duration-fast) var(--apx-ease-standard);
}

.banner-footer a:hover span {
  transform: translate(2px, -2px);
}

a:focus-visible {
  outline: 2px solid var(--apx-forest-300);
  outline-offset: 4px;
}

@media (min-width: 1024px) {
  .banner-frame {
    aspect-ratio: 16 / 9;
    min-height: 640px;
    max-height: 900px;
  }
}

/* Laptop */
@media (max-width: 1500px) {
  .cylinder-phases {
    display: none;
  }

  .engine-hud {
    grid-template-columns: minmax(150px, 0.8fr) minmax(240px, 1.55fr) auto;
  }
}

@media (max-width: 1320px) {
  .banner-nav__links {
    gap: 20px;
  }

  .phase-readout__stage span {
    display: none;
  }

  .phase-readout strong {
    font-size: 20px;
  }
}

@media (max-width: 1120px) {
  .banner-nav__links {
    display: none;
  }

  .banner-nav {
    justify-content: space-between;
  }

  .banner-content {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
  }

  .banner-copy h1 {
    font-size: clamp(40px, 4.8vw, 52px);
  }

  .proof-strip {
    margin-top: 32px;
  }
}

/* Tablet and mobile: keep the engine intact below the copy. */
@media (max-width: 1023px) {
  body {
    display: block;
    background: var(--apx-charcoal-900);
  }

  .banner-frame {
    width: 100%;
    min-height: 100vh;
    min-height: 100svh;
    overflow: hidden;
  }

  .banner-frame::after {
    top: 48%;
    right: -20%;
    width: 92%;
  }

  .banner-nav {
    min-height: 76px;
  }

  .banner-content {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
    padding-top: 42px;
    padding-bottom: 42px;
  }

  .banner-copy {
    max-width: 720px;
  }

  .banner-copy h1 {
    font-size: clamp(42px, 7vw, 60px);
  }

  .banner-lede {
    max-width: 58ch;
  }

  .engine-stage {
    min-height: 560px;
    padding-left: 0;
  }

  .engine-stage::before {
    top: 2%;
    right: 12%;
    bottom: 8%;
    left: 20%;
  }

  .engine-hud {
    grid-template-columns: minmax(140px, 0.8fr) minmax(240px, 1.6fr) auto;
  }
}

/* Phone */
@media (max-width: 640px) {
  .banner-nav {
    min-height: 68px;
    gap: 16px;
    padding-inline: 20px;
  }

  .brand-lockup img {
    height: 38px;
  }

  .brand-lockup {
    min-height: 44px;
  }

  .nav-cta {
    min-height: 44px;
    padding-inline: 14px;
    font-size: 11px;
  }

  .nav-cta__arrow {
    display: none;
  }

  .banner-content {
    gap: 22px;
    padding: 32px 20px;
  }

  .eyebrow {
    margin-bottom: 18px;
    font-size: 9px;
  }

  .eyebrow__rule {
    width: 22px;
  }

  .banner-copy h1 {
    font-size: clamp(40px, 12.5vw, 54px);
    letter-spacing: -0.045em;
  }

  .banner-lede {
    margin-top: 20px;
    font-size: 14px;
  }

  .banner-actions {
    display: grid;
    grid-template-columns: 1fr;
    margin-top: 26px;
  }

  .cta {
    width: 100%;
    min-width: 0;
  }

  .proof-strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 26px;
    padding-top: 16px;
  }

  .proof-strip div {
    display: block;
    padding: 0 8px 0 0;
    border-bottom: 0;
  }

  .proof-strip div + div {
    padding-left: 10px;
    border-left: 1px solid var(--apx-charcoal-800);
  }

  .proof-strip dt {
    margin: 0 0 4px;
    font-size: 9px;
  }

  .proof-strip dd {
    font-size: 10px;
    line-height: 1.4;
    text-align: left;
  }

  .engine-stage {
    min-height: 460px;
  }

  .engine-stage::before {
    top: 4%;
    right: 4%;
    bottom: 12%;
    left: 7%;
  }

  .engine-stage__drawing {
    padding-top: 4px;
  }

  .engine-hud {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 12px 16px;
    padding-top: 14px;
  }

  .phase-progress {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .phase-readout {
    grid-column: 1;
    grid-row: 1;
  }

  .crank-readout {
    grid-column: 2;
    grid-row: 1;
  }

  .phase-readout strong {
    font-size: 22px;
  }

  .phase-readout__stage span {
    display: none;
  }

  .phase-steps li {
    font-size: 9px;
  }

  .phase-steps li span {
    display: none;
  }

  .crank-readout strong {
    font-size: 19px;
  }

  .banner-footer {
    display: grid;
    min-height: 82px;
    gap: 8px;
    padding: 16px 20px;
  }

  .banner-footer p {
    gap: 10px;
  }

  .banner-footer a {
    min-height: 44px;
  }

  .footer-index {
    display: none;
  }
}

@media (max-width: 390px) {
  .banner-copy h1 {
    font-size: 39px;
  }

  .engine-stage {
    min-height: 430px;
  }
}

/* Short desktop viewports */
@media (min-width: 1024px) and (max-height: 780px) {
  .banner-nav {
    min-height: 74px;
  }

  .banner-content {
    padding-top: 20px;
    padding-bottom: 12px;
  }

  .eyebrow {
    margin-bottom: 18px;
  }

  .banner-lede {
    margin-top: 18px;
  }

  .banner-actions {
    margin-top: 24px;
  }

  .proof-strip {
    margin-top: 26px;
    padding-top: 14px;
  }

  .engine-hud {
    padding-top: 10px;
  }

  .banner-footer {
    min-height: 48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

  .engine-draw {
    stroke-dashoffset: 0;
  }

  .cycle-status__dot {
    box-shadow: none;
  }

  .gas-trace {
    filter: none;
  }
}

/*
 * Embed mode for the public homepage hero.
 * Loads the same live SVG and animation as the standalone banner, but shows
 * only the engine drawing so it can sit inside an existing technical panel.
 */
.banner-document--engine-embed,
.banner-document--engine-embed body {
  width: 100%;
  min-width: 0;
  height: 100%;
  min-height: 0;
  margin: 0;
  overflow: hidden;
  background: var(--apx-charcoal-900);
}

.banner-document--engine-embed body {
  display: block;
}

.banner-document--engine-embed .banner-frame {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  max-height: none;
  aspect-ratio: auto;
  background: transparent;
}

.banner-document--engine-embed .banner-frame::after,
.banner-document--engine-embed .banner-nav,
.banner-document--engine-embed .banner-copy,
.banner-document--engine-embed .banner-footer,
.banner-document--engine-embed .engine-stage__meta,
.banner-document--engine-embed .engine-hud {
  display: none;
}

.banner-document--engine-embed .banner-content {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  padding: 0;
}

.banner-document--engine-embed .engine-stage {
  width: 100%;
  height: 100%;
  min-height: 0;
  padding: 0;
}

.banner-document--engine-embed .engine-stage::before {
  top: 4%;
  right: 8%;
  bottom: 7%;
  left: 10%;
}

.banner-document--engine-embed .engine-stage__drawing {
  width: 100%;
  height: 100%;
  flex: none;
  padding: 0;
}

.banner-document--engine-embed .engine-svg {
  width: 100%;
  height: 100%;
  overflow: visible;
  transform: scale(1.14);
  transform-origin: center;
}

/*
 * Light-surface embed:
 * the homepage supplies its own paper grid, so the iframe stays transparent
 * and the engineering linework switches from light-on-dark to dark-on-light.
 */
.banner-document--engine-light,
.banner-document--engine-light body,
.banner-document--engine-light .banner-frame,
.banner-document--engine-light .banner-content,
.banner-document--engine-light .engine-stage {
  background: transparent;
}

.banner-document--engine-light .engine-stage::before {
  border-color: var(--apx-line-strong);
  opacity: 0.55;
}

.banner-document--engine-light .engine-svg {
  --apx-on-dark: var(--apx-ink);
  --apx-on-dark-muted: var(--apx-ink-muted);
  --apx-slate-300: var(--apx-slate-500);
  --apx-charcoal-950: var(--apx-white);
  --apx-charcoal-900: var(--apx-white);
  --apx-forest-300: var(--apx-forest-700);
  --apx-forest-200: var(--apx-forest-600);
  --apx-forest-500: var(--apx-forest-600);
  --apx-forest-900: var(--apx-forest-100);
}

.banner-document--engine-light .cylinder-index,
.banner-document--engine-light .engine-callouts text {
  opacity: 0.72;
}