:root {
  --page: #f7f8f5;
  --paper: #ffffff;
  --ink: #12120f;
  --muted: #666a61;
  --line: #dde1d8;
  --soft: #eff2ec;
  --black: #11110f;
  --yellow: #f2c84b;
  --orange: #e66032;
  --green: #23784b;
  --blue: #2f6786;
  --shadow: 0 18px 44px rgba(17, 17, 15, 0.08);
  --tight-shadow: 0 8px 24px rgba(17, 17, 15, 0.08);
  --radius: 8px;
  --rail: 248px;
}

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

html {
  scroll-behavior: auto;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(17, 17, 15, 0.035) 1px, transparent 1px) 0 0 / 32px 32px,
    var(--page);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.52;
  overflow-x: hidden;
}

body[data-lang="zh"] {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

img {
  display: block;
  max-width: 100%;
}

button,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

a {
  color: inherit;
}

p,
h1,
h2,
h3 {
  margin-top: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  min-height: 68px;
  padding: 10px clamp(14px, 2.5vw, 28px);
  display: grid;
  grid-template-columns: minmax(210px, auto) minmax(0, 1fr);
  align-items: center;
  gap: 18px;
  background: rgba(247, 248, 245, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  text-decoration: none;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  color: var(--black);
  background: var(--yellow);
  border: 2px solid var(--black);
  border-radius: var(--radius);
  font-weight: 950;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 0.96rem;
  line-height: 1.08;
}

.brand small {
  color: var(--muted);
  font-size: 0.76rem;
}

.navlinks {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 4px;
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.navlinks a {
  min-height: 34px;
  padding: 8px 10px;
  border-radius: 6px;
  color: #353832;
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 850;
}

.navlinks a:hover {
  background: var(--soft);
}

.mobile-chapter-nav {
  display: none;
}

.image-tools,
.menu-tabs {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: 0 1px 0 rgba(17, 17, 15, 0.04);
}

.image-tools button,
.menu-tabs button,
.primary-button {
  min-height: 34px;
  border: 0;
  border-radius: 6px;
  padding: 0 12px;
  cursor: pointer;
  color: var(--ink);
  background: transparent;
  font-weight: 900;
  font-size: 0.82rem;
}

.image-tools button.active,
.menu-tabs button.active {
  color: var(--paper);
  background: var(--black);
}

.manual-shell {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  align-items: start;
}

.manual-rail {
  position: sticky;
  top: 68px;
  min-height: calc(100vh - 68px);
  padding: 28px 18px;
  background: rgba(255, 255, 255, 0.76);
  border-right: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.manual-rail p {
  margin: 0 0 16px;
  color: var(--orange);
  font-size: 0.72rem;
  font-weight: 950;
  text-transform: uppercase;
}

.manual-rail a {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 10px;
  padding: 11px 8px;
  border-radius: var(--radius);
  text-decoration: none;
}

.manual-rail a:hover {
  background: var(--soft);
}

.manual-rail a.active {
  background: var(--black);
  color: var(--paper);
}

.manual-rail a.active span {
  color: var(--black);
  background: var(--yellow);
}

.manual-rail span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  color: var(--paper);
  background: var(--black);
  border-radius: 6px;
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.72rem;
  font-weight: 900;
}

.manual-rail strong {
  line-height: 1.1;
}

.manual-main {
  min-width: 0;
}

.hero,
.section {
  max-width: 1180px;
  margin: 0 auto;
  padding: 54px clamp(18px, 3vw, 44px);
  scroll-margin-top: 96px;
}

.manual-panel {
  margin-top: 22px;
  margin-bottom: 24px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero {
  display: grid;
  grid-template-columns: minmax(280px, 0.82fr) minmax(380px, 1.18fr);
  gap: clamp(24px, 4.4vw, 54px);
  align-items: center;
}

.hero-copy {
  max-width: 560px;
}

.overline {
  margin: 0 0 10px;
  color: var(--orange);
  font-size: 0.75rem;
  font-weight: 950;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1 {
  margin-bottom: 16px;
  font-size: clamp(2.6rem, 5.2vw, 5.2rem);
  line-height: 0.95;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(1.65rem, 2.9vw, 2.65rem);
  line-height: 1.04;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 7px;
  font-size: 1.02rem;
  line-height: 1.22;
}

.hero-lede,
.section-head p,
.part-detail p,
.menu-card p,
.trouble-card p,
.calibration-card p,
.support-text {
  color: var(--muted);
}

.hero-lede {
  max-width: 520px;
  font-size: 1.08rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.hero-actions {
  margin: 24px 0 16px;
}

.primary-link,
.secondary-link,
.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 16px;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 950;
}

.primary-link,
.primary-button {
  color: var(--paper);
  background: var(--black);
}

.secondary-link {
  color: var(--black);
  background: var(--yellow);
  border: 1px solid rgba(17, 17, 15, 0.18);
}

.operator-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin: 0 0 18px;
}

.operator-strip a {
  min-height: 82px;
  padding: 12px;
  display: grid;
  align-content: start;
  gap: 3px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
}

.operator-strip span {
  color: var(--orange);
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.76rem;
  font-weight: 950;
}

.operator-strip small {
  color: var(--muted);
  font-size: 0.76rem;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin: 0;
}

.summary-grid div {
  min-height: 88px;
  padding: 14px;
  background: #f9faf7;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.summary-grid dt {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 900;
  text-transform: uppercase;
}

.summary-grid dd {
  margin: 5px 0 0;
  font-size: 1.04rem;
  font-weight: 950;
}

.product-stage {
  min-width: 0;
}

.image-card-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.image-card-head p {
  margin: 0 0 2px;
  color: var(--orange);
  font-size: 0.72rem;
  font-weight: 950;
  text-transform: uppercase;
}

.image-card-head strong {
  display: block;
  font-size: 0.96rem;
}

.image-wrap {
  position: relative;
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--tight-shadow);
  aspect-ratio: 0.96;
}

.image-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hotspot {
  position: absolute;
  z-index: 2;
  width: 7px;
  height: 7px;
  transform: translate(-50%, -50%);
  border: 1px solid var(--paper);
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 1px rgba(230, 96, 50, 0.24);
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease;
}

.image-wrap.show-callouts .hotspot {
  opacity: 1;
  pointer-events: auto;
}

.hotspot.active {
  background: var(--yellow);
  border-color: var(--black);
  box-shadow: 0 0 0 2px rgba(242, 200, 75, 0.36);
}

.image-callout-lines {
  position: absolute;
  inset: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease;
}

.image-wrap.show-callouts .image-callout-lines {
  opacity: 1;
}

.image-callout-lines line {
  stroke: var(--orange);
  stroke-width: 0.52;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.image-callouts {
  position: absolute;
  inset: 0;
  z-index: 3;
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease;
}

.image-wrap.show-callouts .image-callouts {
  opacity: 1;
  pointer-events: auto;
}

.image-callout {
  position: absolute;
  transform: translate(-50%, -50%);
  max-width: 118px;
  padding: 0 0 0 7px;
  border: 0;
  border-left: 2px solid var(--orange);
  border-radius: 0;
  color: var(--ink);
  background: transparent;
  appearance: none;
  text-shadow:
    0 1px 2px rgba(255, 255, 255, 0.96),
    0 -1px 2px rgba(255, 255, 255, 0.96),
    1px 0 2px rgba(255, 255, 255, 0.96),
    -1px 0 2px rgba(255, 255, 255, 0.96);
  box-shadow: none;
  cursor: pointer;
  text-align: left;
}

.image-callout span {
  display: block;
  font-size: 0.64rem;
  font-weight: 900;
  line-height: 1.15;
}

.image-callout.active {
  color: var(--black);
  background: transparent;
  border-left-color: var(--yellow);
  text-shadow:
    0 1px 2px rgba(255, 255, 255, 0.98),
    0 -1px 2px rgba(255, 255, 255, 0.98),
    1px 0 2px rgba(255, 255, 255, 0.98),
    -1px 0 2px rgba(255, 255, 255, 0.98);
}

.part-detail {
  margin-top: 10px;
  padding: 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 5px solid var(--orange);
  border-radius: var(--radius);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(240px, 0.42fr) minmax(0, 0.58fr);
  gap: 24px;
  align-items: end;
  margin-bottom: 22px;
}

.section-head p:not(.overline) {
  max-width: 620px;
}

.manual-section {
  border-top: 1px solid rgba(17, 17, 15, 0.08);
}

.step-grid,
.control-grid,
.menu-grid,
.calibration-grid,
.spec-grid,
.trouble-list {
  display: grid;
  gap: 12px;
}

.step-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.control-grid,
.menu-grid,
.calibration-grid,
.spec-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.step-card,
.control-card,
.menu-card,
.calibration-card,
.spec-card,
.trouble-card,
.part-button,
.state-card {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 1px 0 rgba(17, 17, 15, 0.03);
}

.step-card,
.control-card,
.menu-card,
.calibration-card,
.spec-card,
.trouble-card {
  padding: 18px;
}

.step-card {
  min-height: 220px;
}

.install-video {
  display: grid;
  grid-template-columns: minmax(220px, 0.34fr) minmax(0, 0.66fr);
  gap: 18px;
  align-items: center;
  margin-bottom: 14px;
  padding: 18px;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  border-left: 5px solid var(--orange);
  border-radius: var(--radius);
  box-shadow: 0 1px 0 rgba(17, 17, 15, 0.03);
}

.install-video-copy h3 {
  margin-bottom: 8px;
  font-size: 1.2rem;
}

.install-video-copy p:not(.overline) {
  margin: 0;
  color: var(--muted);
}

.install-video-actions {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.install-video-link {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: fit-content;
  padding: 0 14px;
  color: var(--paper);
  background: var(--black);
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 950;
}

.install-video-actions small {
  color: var(--muted);
  font-weight: 800;
  line-height: 1.4;
}

.install-video-frame {
  overflow: hidden;
  background: #11110f;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  aspect-ratio: 16 / 9;
}

.install-video-frame iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
}

.audio-learn-guide {
  display: grid;
  gap: 14px;
}

.audio-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  align-items: start;
}

.audio-apps,
.audio-player-card {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 1px 0 rgba(17, 17, 15, 0.03);
}

.audio-apps {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  padding: 14px;
}

.audio-apps .overline {
  grid-column: 1 / -1;
  margin-bottom: 0;
}

.audio-mode-note {
  grid-column: 1 / -1;
  margin: -4px 0 2px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.45;
}

.audio-app-card {
  min-height: 78px;
  display: grid;
  gap: 4px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--paper);
  cursor: pointer;
  text-align: left;
}

.audio-app-card span,
.audio-card-head .audio-map,
.audio-play span,
.audio-checkline span {
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 950;
  text-transform: uppercase;
}

.audio-app-card strong {
  font-size: 1.15rem;
}

.audio-app-card small {
  color: var(--muted);
  font-weight: 800;
}

.audio-app-card.primary {
  border-color: rgba(230, 96, 50, 0.42);
}

.audio-app-card.active {
  color: var(--ink);
  background: var(--paper);
  border-color: var(--orange);
  box-shadow: inset 5px 0 0 var(--orange);
}

.audio-app-card.active span,
.audio-app-card.active small {
  color: var(--muted);
}

.audio-player-card {
  padding: 20px;
  border-left: 5px solid var(--orange);
}

.audio-card-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: start;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.audio-card-head h3 {
  font-size: 1.25rem;
}

.audio-card-head p {
  max-width: 680px;
  margin-bottom: 0;
  color: var(--muted);
}

.audio-card-head .audio-map {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  padding: 0 10px;
  color: var(--black);
  background: var(--yellow);
  border: 1px solid rgba(17, 17, 15, 0.18);
  border-radius: 6px;
  white-space: nowrap;
}

.delver-app-links {
  display: grid;
  grid-template-columns: minmax(180px, 0.35fr) minmax(0, 0.65fr);
  gap: 14px;
  align-items: stretch;
  margin-top: 16px;
  padding: 14px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.delver-app-links strong {
  display: block;
  margin-bottom: 4px;
  font-size: 0.95rem;
}

.delver-app-links p {
  margin: 0;
  color: var(--muted);
}

.delver-app-link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.delver-app-link {
  min-height: 82px;
  display: grid;
  gap: 3px;
  align-content: center;
  padding: 12px;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
}

.delver-app-link span {
  font-size: 1.08rem;
  font-weight: 950;
}

.delver-app-link small {
  color: var(--muted);
  font-weight: 850;
}

.delver-app-link em {
  color: var(--orange);
  font-style: normal;
  font-size: 0.78rem;
  font-weight: 950;
  text-transform: uppercase;
}

.audio-guide-intro {
  margin-top: 16px;
  padding: 14px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.audio-guide-intro strong {
  display: block;
  margin-bottom: 4px;
  font-size: 0.95rem;
}

.audio-guide-intro p {
  margin: 0;
  color: var(--muted);
}

.machine-route-guide {
  display: grid;
  gap: 12px;
  margin-top: 16px;
  padding: 16px 0 18px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.machine-route-copy {
  max-width: 880px;
}

.machine-route-copy .overline {
  margin-bottom: 5px;
  color: var(--orange);
}

.machine-route-copy strong {
  display: block;
  margin-bottom: 5px;
  font-size: 1rem;
}

.machine-route-copy p {
  margin: 0;
  color: var(--muted);
}

.machine-route-steps {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  margin: 4px 0 0;
  padding: 0;
  list-style: none;
}

.machine-route-steps::before {
  content: "";
  position: absolute;
  top: 20px;
  left: 20px;
  right: 20px;
  height: 2px;
  background: linear-gradient(90deg, rgba(230, 96, 50, 0.7), rgba(242, 200, 75, 0.85));
}

.machine-route-steps li {
  position: relative;
  z-index: 1;
  min-width: 0;
  display: grid;
  grid-template-rows: 40px auto;
  gap: 10px;
  align-items: start;
  padding: 0;
}

.machine-route-index {
  width: 40px;
  height: 40px;
  display: inline-grid;
  place-items: center;
  color: var(--black);
  background: var(--yellow);
  border: 2px solid rgba(17, 17, 15, 0.18);
  border-radius: 6px;
  box-shadow: 0 0 0 5px var(--paper);
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 1rem;
  font-weight: 950;
}

.machine-route-steps strong,
.machine-route-steps p,
.machine-route-steps em {
  display: block;
}

.machine-route-steps strong {
  font-size: 0.92rem;
  line-height: 1.25;
}

.machine-route-steps p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.32;
}

.machine-route-steps em {
  margin-top: 7px;
  color: var(--orange);
  font-style: normal;
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.75rem;
  font-weight: 950;
}

.audio-guide-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.audio-guide-steps li {
  min-width: 0;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 9px;
  align-items: start;
  padding: 12px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.audio-guide-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  color: var(--black);
  background: var(--yellow);
  border: 1px solid rgba(17, 17, 15, 0.18);
  border-radius: 6px;
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-weight: 950;
}

.audio-guide-steps strong {
  display: block;
  font-size: 0.88rem;
  line-height: 1.28;
}

.audio-guide-steps p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.35;
}

.audio-play-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.audio-play {
  position: relative;
  isolation: isolate;
  min-height: 92px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 44px;
  gap: 4px;
  align-content: center;
  align-items: center;
  overflow: hidden;
  border: 1px solid rgba(17, 17, 15, 0.2);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--paper);
  background:
    linear-gradient(135deg, #0d0f12 0%, #172332 54%, #11110f 100%);
  text-align: left;
  padding: 15px 16px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.16),
    0 12px 28px rgba(17, 17, 15, 0.16);
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
  -webkit-tap-highlight-color: transparent;
}

.audio-play::before {
  content: "";
  position: absolute;
  inset: -1px;
  z-index: -1;
  background: linear-gradient(120deg, transparent 0%, rgba(255, 255, 255, 0.2) 42%, transparent 66%);
  transform: translateX(-120%);
  animation: audioButtonSweep 3.2s ease-in-out infinite;
}

.audio-play::after {
  content: "▶";
  grid-column: 2;
  grid-row: 1 / span 3;
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--black);
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 999px;
  box-shadow: 0 8px 18px rgba(17, 17, 15, 0.18);
  font-size: 0.82rem;
  line-height: 1;
}

.audio-play:hover,
.audio-play:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(255, 204, 66, 0.7);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 16px 32px rgba(17, 17, 15, 0.2);
}

.audio-play:active {
  transform: translateY(1px) scale(0.99);
}

.audio-play.fail {
  color: var(--ink);
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96) 0%, rgba(244, 246, 241, 0.96) 52%, rgba(226, 236, 240, 0.96) 100%);
  border-color: rgba(17, 17, 15, 0.38);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.7),
    0 10px 24px rgba(17, 17, 15, 0.1);
}

.audio-play.fail::before {
  background: linear-gradient(120deg, transparent 0%, rgba(255, 204, 66, 0.34) 42%, transparent 66%);
}

.audio-play.fail::after {
  color: var(--paper);
  background: var(--black);
  border-color: rgba(17, 17, 15, 0.22);
}

.audio-play span {
  position: relative;
  z-index: 1;
  grid-column: 1;
  color: inherit;
  opacity: 0.76;
}

.audio-play strong {
  position: relative;
  z-index: 1;
  grid-column: 1;
  font-size: 1.35rem;
}

.audio-play em {
  position: relative;
  z-index: 1;
  grid-column: 1;
  color: inherit;
  font-size: 0.82rem;
  font-style: normal;
  font-weight: 900;
  opacity: 0.82;
}

@keyframes audioButtonSweep {
  0%, 44% {
    transform: translateX(-120%);
  }

  68%, 100% {
    transform: translateX(120%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .audio-play::before {
    animation: none;
    transform: translateX(0);
    opacity: 0;
  }
}

.audio-checkline,
.audio-notes {
  margin-top: 14px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--soft);
}

.audio-checkline {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  align-items: center;
}

.audio-checkline strong {
  color: var(--green);
}

.audio-notes p {
  margin: 0;
  color: var(--muted);
}

.audio-notes p + p {
  margin-top: 6px;
}

.step-number,
.keycap,
.state-code {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 38px;
  height: 34px;
  margin-bottom: 14px;
  border-radius: 6px;
  color: var(--black);
  background: var(--yellow);
  border: 1px solid rgba(17, 17, 15, 0.18);
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-weight: 950;
}

.support-text {
  margin-top: 8px;
  font-size: 0.9rem;
}

.split {
  display: grid;
  grid-template-columns: minmax(240px, 0.36fr) minmax(360px, 0.64fr);
  gap: 24px;
  align-items: start;
}

.split .section-head {
  position: sticky;
  top: 90px;
  display: block;
}

.parts-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.part-button {
  width: 100%;
  min-height: 112px;
  padding: 14px;
  text-align: left;
  cursor: pointer;
}

.part-button.active {
  border-color: var(--orange);
  box-shadow: inset 5px 0 0 var(--orange);
}

.part-button strong,
.part-button span {
  display: block;
}

.part-button span {
  color: var(--muted);
  font-size: 0.9rem;
}

.state-flow {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.state-card {
  min-height: 154px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}

.state-card-head {
  min-height: 30px;
  display: flex;
  align-items: center;
}

.state-card .state-code {
  width: auto;
  min-width: 0;
  height: 28px;
  padding: 0 8px;
  margin-bottom: 0;
  font-size: 0.78rem;
  line-height: 1;
  white-space: nowrap;
}

.state-card p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.46;
}

.state-card.active {
  border-color: var(--orange);
  box-shadow: inset 0 0 0 2px var(--orange);
}

.state-card[data-tone="good"] .state-code {
  color: var(--paper);
  background: var(--green);
}

.state-card[data-tone="warn"] .state-code {
  color: var(--paper);
  background: var(--orange);
}

.control-head {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 10px;
}

.control-head .keycap {
  flex: 0 0 auto;
  width: auto;
  min-width: 0;
  height: 28px;
  padding: 0 8px;
  margin: 0;
  font-size: 0.78rem;
  line-height: 1;
  white-space: nowrap;
}

.control-head div {
  min-width: 0;
}

.menu-tabs {
  margin-bottom: 14px;
}

.oled-simulator {
  display: grid;
  grid-template-columns: minmax(280px, 0.42fr) minmax(360px, 0.58fr);
  gap: 18px;
  align-items: stretch;
  margin-bottom: 20px;
  padding: 18px;
  background: rgba(17, 17, 15, 0.96);
  border: 1px solid rgba(17, 17, 15, 0.18);
  border-radius: var(--radius);
  box-shadow: var(--tight-shadow);
}

.oled-copy {
  padding: 6px 4px;
  color: var(--paper);
}

.oled-copy .overline {
  color: var(--yellow);
}

.oled-copy h3 {
  max-width: 480px;
  font-size: 1.55rem;
}

.oled-copy p:not(.overline) {
  max-width: 540px;
  color: rgba(255, 255, 255, 0.72);
}

.oled-meta {
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
}

.oled-meta div {
  padding: 12px;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
}

.oled-meta dt {
  margin-bottom: 5px;
  color: var(--yellow);
  font-size: 0.72rem;
  font-weight: 950;
  text-transform: uppercase;
}

.oled-meta dd {
  margin: 0;
  color: rgba(255, 255, 255, 0.86);
}

#oledBreadcrumb {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.88rem;
  overflow-wrap: anywhere;
}

#oledTooltip {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

#oledTooltip .zh {
  color: rgba(255, 255, 255, 0.58);
}

.lang-en #oledTooltip .zh {
  display: none;
}

.lang-zh #oledTooltip .zh {
  order: -1;
  color: rgba(255, 255, 255, 0.9);
}

.lang-zh #oledTooltip .en {
  color: rgba(255, 255, 255, 0.58);
}

.oled-device {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 128px;
  gap: 16px;
  align-items: center;
  justify-items: stretch;
}

.oled-screen-stack {
  min-width: 0;
  display: grid;
  gap: 12px;
  justify-items: center;
}

#oled-canvas {
  width: min(100%, 512px);
  height: auto;
  background: #020508;
  border: 10px solid #2c302d;
  border-radius: var(--radius);
  box-shadow: inset 0 0 0 1px rgba(0, 229, 200, 0.24), 0 18px 38px rgba(0, 0, 0, 0.34);
  image-rendering: pixelated;
}

.oled-controls {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  align-content: center;
}

.oled-hw-btn {
  min-height: 54px;
  border: 1px solid rgba(17, 17, 15, 0.22);
  border-radius: 6px;
  color: var(--black);
  background: var(--yellow);
  box-shadow: inset 0 -4px 0 rgba(17, 17, 15, 0.18), 0 6px 12px rgba(0, 0, 0, 0.22);
  cursor: pointer;
  font-weight: 950;
}

.oled-hw-btn:hover {
  background: #f6d766;
}

.oled-hw-btn:active {
  color: var(--black);
  background: var(--yellow);
}

.menu-card small {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--orange);
  font-weight: 950;
  text-transform: uppercase;
}

.table-wrap {
  overflow-x: auto;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

table {
  width: 100%;
  min-width: 760px;
  border-collapse: collapse;
}

caption {
  padding: 16px;
  color: var(--muted);
  text-align: left;
  font-weight: 900;
}

th,
td {
  padding: 14px 16px;
  border-top: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  color: #353832;
  background: var(--soft);
  font-size: 0.76rem;
  text-transform: uppercase;
}

td:first-child {
  font-weight: 950;
}

.calibration-card {
  min-height: 262px;
}

.calibration-card ul {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--muted);
}

.search-box {
  display: block;
  margin-bottom: 16px;
  padding: 14px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.search-box span {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-weight: 950;
}

.search-box input {
  width: 100%;
  min-height: 48px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcfa;
  color: var(--ink);
}

.trouble-card {
  display: grid;
  grid-template-columns: minmax(180px, 0.32fr) minmax(0, 0.68fr);
  gap: 18px;
  border-left: 5px solid var(--orange);
}

.fix-list {
  margin: 0;
  padding-left: 18px;
}

.fix-list li + li {
  margin-top: 8px;
}

.spec-card strong {
  display: block;
  margin-bottom: 6px;
  font-size: 1.12rem;
}

.footer {
  padding: 34px 16px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--line);
}

.lang-secret-toggle {
  position: fixed;
  left: 10px;
  bottom: 10px;
  z-index: 35;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  padding: 0;
  background: transparent;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  opacity: 0.38;
  font-size: 1.08rem;
  line-height: 1;
  transform: scale(0.96);
  transition: opacity 160ms ease, transform 160ms ease;
  appearance: none;
  -webkit-tap-highlight-color: transparent;
}

.lang-secret-toggle:hover,
.lang-secret-toggle:focus-visible {
  opacity: 0.88;
  transform: scale(1.04);
  outline: none;
}

.lang-secret-toggle:active {
  transform: scale(0.92);
}

@media (max-width: 1180px) {
  :root {
    --rail: 212px;
  }

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

  .step-grid,
  .control-grid,
  .menu-grid,
  .calibration-grid,
  .spec-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 920px) {
  .topbar {
    grid-template-columns: 1fr;
  }

  .navlinks {
    display: none;
  }

  .manual-shell,
  .hero,
  .split,
  .section-head,
  .install-video,
  .audio-card-head,
  .oled-simulator {
    grid-template-columns: 1fr;
  }

  .audio-apps .overline {
    grid-column: 1 / -1;
  }

  .audio-guide-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .machine-route-steps {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .machine-route-steps::before {
    top: 0;
    right: auto;
    bottom: 0;
    left: 20px;
    width: 2px;
    height: auto;
    background: linear-gradient(180deg, rgba(230, 96, 50, 0.7), rgba(242, 200, 75, 0.85));
  }

  .machine-route-steps li {
    grid-template-columns: 40px minmax(0, 1fr);
    grid-template-rows: auto;
  }

  .audio-card-head .audio-map {
    justify-self: start;
    white-space: normal;
  }

  .delver-app-links {
    grid-template-columns: 1fr;
  }

  .oled-device {
    grid-template-columns: 1fr;
  }

  .manual-rail {
    display: none;
  }

  .mobile-chapter-nav {
    position: sticky;
    top: 68px;
    z-index: 29;
    display: block;
    padding: 10px 14px;
    background: rgba(247, 248, 245, 0.94);
    border-bottom: 1px solid var(--line);
    backdrop-filter: blur(18px);
  }

  .mobile-nav-toggle {
    width: 100%;
    min-height: 58px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 2px 12px;
    align-items: center;
    padding: 10px 12px;
    color: var(--ink);
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 1px 0 rgba(17, 17, 15, 0.04);
    cursor: pointer;
    text-align: left;
    list-style: none;
  }

  .mobile-nav-toggle::-webkit-details-marker {
    display: none;
  }

  .mobile-nav-toggle span {
    grid-column: 1 / 2;
    color: var(--orange);
    font-size: 0.72rem;
    font-weight: 950;
    text-transform: uppercase;
  }

  .mobile-nav-toggle strong {
    grid-column: 1 / 2;
    display: block;
    overflow: hidden;
    font-size: 1.02rem;
    line-height: 1.18;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .mobile-nav-toggle em {
    grid-row: 1 / 3;
    grid-column: 2 / 3;
    min-height: 34px;
    display: inline-flex;
    align-items: center;
    padding: 0 12px;
    color: var(--paper);
    background: var(--black);
    border-radius: 6px;
    font-style: normal;
    font-size: 0.82rem;
    font-weight: 950;
  }

  .mobile-nav-panel {
    position: absolute;
    top: calc(100% - 4px);
    right: 14px;
    left: 14px;
    z-index: 30;
    padding: 14px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--tight-shadow);
  }

  .mobile-nav-panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 10px;
  }

  .mobile-nav-panel-head strong {
    font-size: 1rem;
  }

  .mobile-nav-panel-head button {
    min-height: 34px;
    padding: 0 12px;
    color: var(--ink);
    background: var(--soft);
    border: 1px solid var(--line);
    border-radius: 6px;
    cursor: pointer;
    font-weight: 900;
  }

  .mobile-nav-list {
    display: grid;
    gap: 8px;
  }

  .mobile-nav-list a {
    min-height: 48px;
    display: grid;
    grid-template-columns: 32px minmax(0, 1fr);
    gap: 10px;
    align-items: center;
    padding: 8px 10px;
    color: var(--ink);
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    text-decoration: none;
  }

  .mobile-nav-list a.active {
    color: var(--paper);
    background: var(--black);
    border-color: var(--black);
  }

  .mobile-nav-list span {
    width: 28px;
    height: 28px;
    display: inline-grid;
    place-items: center;
    color: var(--paper);
    background: var(--black);
    border-radius: 6px;
    font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
    font-size: 0.8rem;
    font-weight: 950;
  }

  .mobile-nav-list a.active span {
    color: var(--black);
    background: var(--yellow);
  }

  .mobile-nav-list strong {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .hero,
  .section {
    padding: 38px 18px;
    scroll-margin-top: 148px;
  }

  .manual-panel {
    margin: 14px 12px 16px;
  }

  .split .section-head {
    position: static;
  }
}

@media (max-width: 640px) {
  .topbar {
    align-items: start;
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 2.42rem;
  }

  .hero,
  .section {
    scroll-margin-top: 148px;
  }

  .operator-strip,
  .summary-grid,
  .step-grid,
  .audio-apps,
  .delver-app-link-grid,
  .audio-guide-steps,
  .audio-play-row,
  .state-flow,
  .control-grid,
  .menu-grid,
  .calibration-grid,
  .spec-grid,
  .parts-list,
  .trouble-card {
    grid-template-columns: 1fr;
  }

  .image-card-head {
    align-items: stretch;
    flex-direction: column;
  }

  .image-tools {
    width: 100%;
  }

  .image-tools button {
    flex: 1;
  }

  .image-wrap {
    aspect-ratio: 0.75;
  }

  .hotspot {
    width: 6px;
    height: 6px;
  }

  .image-callout {
    max-width: 106px;
    padding-left: 6px;
  }

  .image-callout span {
    font-size: 0.54rem;
  }

  .audio-player-card {
    padding: 16px;
  }

  .audio-play {
    min-height: 90px;
  }

  .menu-tabs {
    width: 100%;
    overflow-x: auto;
  }

  .oled-simulator {
    padding: 14px;
  }

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

}