:root {
  color-scheme: light;
  --ink: #172027;
  --muted: #5c6972;
  --soft: #eef2f3;
  --line: #d7dee2;
  --panel: #ffffff;
  --steel: #6f7b82;
  --graphite: #252d32;
  --teal: #147d7b;
  --teal-dark: #0d5556;
  --amber: #c7892b;
  --red: #a6403c;
  --shadow: 0 24px 70px rgba(18, 30, 37, 0.16);
  --radius: 8px;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #f6f7f7;
  color: var(--ink);
}

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

button,
input {
  font: inherit;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 66px;
  padding: 0 32px;
  color: #f7fbfb;
  background: rgba(12, 20, 24, 0.68);
  border-bottom: 1px solid rgba(255, 255, 255, 0.13);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 750;
}

.brand-mark {
  width: 28px;
  height: 28px;
  border: 2px solid rgba(255, 255, 255, 0.88);
  border-radius: 50%;
  position: relative;
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 11px;
  height: 2px;
  background: var(--amber);
  transform-origin: 0 50%;
}

.brand-mark::before {
  transform: rotate(22deg);
}

.brand-mark::after {
  transform: rotate(142deg);
}

.nav-links {
  display: flex;
  gap: 24px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.78);
}

.nav-links a {
  padding: 22px 0;
}

.nav-links a:hover {
  color: #fff;
}

.hero {
  position: relative;
  min-height: calc(100vh - 44px);
  overflow: hidden;
  display: grid;
  align-items: center;
  padding: 86px 32px 30px;
  color: white;
}

.hero-media,
.hero-media img,
.hero-overlay {
  position: absolute;
  inset: 0;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(10, 16, 20, 0.91) 0%, rgba(12, 18, 21, 0.75) 36%, rgba(12, 18, 21, 0.22) 72%),
    linear-gradient(0deg, rgba(10, 16, 20, 0.58), rgba(10, 16, 20, 0.08) 48%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(1120px, 100%);
  margin: 0 auto;
  padding-top: 20px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #82d8d3;
}

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

h1 {
  max-width: 720px;
  margin-bottom: 20px;
  font-size: clamp(46px, 7vw, 92px);
  line-height: 0.98;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 710px;
  color: rgba(255, 255, 255, 0.83);
  font-size: 19px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 30px 0 30px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 4px;
  font-weight: 760;
}

.primary-action {
  background: #d89932;
  color: #101417;
}

.secondary-action {
  border: 1px solid rgba(255, 255, 255, 0.48);
  color: #fff;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(120px, 1fr));
  max-width: 760px;
  margin: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
  border-left: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-metrics div {
  padding: 18px 18px 16px;
  border-right: 1px solid rgba(255, 255, 255, 0.16);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-metrics dt {
  color: rgba(255, 255, 255, 0.61);
  font-size: 13px;
}

.hero-metrics dd {
  margin: 4px 0 0;
  color: #fff;
  font-size: 30px;
  font-weight: 820;
}

.section {
  padding: 92px 32px;
}

.section[id] {
  scroll-margin-top: 82px;
}

.section-head {
  width: min(1120px, 100%);
  margin: 0 auto 36px;
}

.section-head.compact {
  margin-bottom: 26px;
}

.section-head h2 {
  max-width: 820px;
  margin-bottom: 12px;
  font-size: clamp(32px, 4vw, 54px);
  line-height: 1.08;
  letter-spacing: 0;
}

.section-head p:not(.eyebrow) {
  max-width: 860px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.scope-band {
  background: #fff;
}

.scope-grid {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.scope-grid article {
  min-height: 230px;
  padding: 26px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.scope-index {
  display: inline-block;
  margin-bottom: 42px;
  color: var(--amber);
  font-weight: 850;
}

.scope-grid h3,
.architecture-flow h3,
.validation-grid h3,
.calc-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

.scope-grid p,
.architecture-flow p,
.validation-grid p,
.calc-card p,
.check-list {
  color: var(--muted);
  line-height: 1.72;
}

.motion-section {
  background: #edf1f2;
}

.motion-layout {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 22px;
  align-items: stretch;
}

.motion-visual,
.control-panel,
.calc-card,
.validation-grid article {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.7) inset;
}

.motion-visual {
  min-height: 520px;
  padding: 14px;
  overflow: hidden;
}

#igvDiagram {
  width: 100%;
  height: 100%;
  min-height: 490px;
  display: block;
}

.control-panel {
  padding: 24px;
}

.panel-topline {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 18px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.panel-topline strong {
  color: var(--teal-dark);
}

.range-control {
  display: grid;
  gap: 12px;
  font-weight: 760;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--teal);
}

.quick-positions {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin: 18px 0 20px;
}

.quick-positions button {
  min-height: 38px;
  cursor: pointer;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #f5f7f7;
  color: var(--ink);
  font-weight: 750;
}

.quick-positions button:hover,
.quick-positions button.active {
  border-color: var(--teal);
  color: white;
  background: var(--teal);
}

.readouts {
  display: grid;
  gap: 10px;
  margin: 0;
}

.readouts div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
}

.readouts dt {
  color: var(--muted);
  font-size: 14px;
}

.readouts dd {
  margin: 0;
  font-size: 18px;
  font-weight: 820;
}

.panel-note {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.architecture-section {
  background: #f8f9f9;
}

.architecture-flow {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.architecture-flow article {
  min-height: 250px;
  padding: 24px;
  background: #fff;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.architecture-flow span {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  margin-bottom: 42px;
  border-radius: 50%;
  color: white;
  background: var(--graphite);
  font-weight: 820;
}

.calc-section {
  background: #ffffff;
}

.calc-layout {
  width: min(1120px, 100%);
  margin: 0 auto 30px;
  display: grid;
  grid-template-columns: 1fr 1.15fr 0.9fr;
  gap: 18px;
}

.calc-card {
  padding: 26px;
}

.calc-card.highlight {
  border-color: rgba(20, 125, 123, 0.35);
}

.calc-card table {
  width: 100%;
  border-collapse: collapse;
}

.calc-card th,
.calc-card td {
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.calc-card th {
  width: 58%;
  color: var(--muted);
  font-weight: 650;
}

.calc-card td {
  font-weight: 780;
}

.check-list {
  display: grid;
  gap: 12px;
  padding-left: 18px;
  margin: 0;
}

.result-card {
  color: white;
  background: var(--graphite);
  border-color: var(--graphite);
}

.result-card h3,
.result-card p {
  color: white;
}

.result-card p:not(.big-number) {
  color: rgba(255, 255, 255, 0.76);
}

.big-number {
  margin: 8px 0 14px;
  color: #f2a941;
  font-size: 46px;
  font-weight: 860;
  line-height: 1;
}

.table-wrap {
  width: min(1120px, 100%);
  margin: 0 auto;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.evaluation-table {
  width: 100%;
  min-width: 860px;
  border-collapse: collapse;
  background: #fff;
}

.evaluation-table caption {
  padding: 16px 18px;
  text-align: left;
  color: var(--ink);
  font-weight: 830;
  border-bottom: 1px solid var(--line);
}

.evaluation-table th,
.evaluation-table td {
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  line-height: 1.6;
}

.evaluation-table thead th {
  color: #fff;
  background: var(--graphite);
  font-size: 14px;
}

.evaluation-table tbody th {
  width: 15%;
  color: var(--teal-dark);
}

.evaluation-table td {
  color: var(--muted);
}

.validation-section {
  background: #edf1f2;
}

.validation-grid {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.validation-grid article {
  padding: 24px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 32px;
  color: rgba(255, 255, 255, 0.68);
  background: #11191d;
  font-size: 14px;
}

.site-footer p {
  margin: 0;
}

.ring {
  fill: none;
  stroke: #9aa6ac;
  stroke-width: 18;
}

.inner-ring {
  fill: none;
  stroke: #cdd5d9;
  stroke-width: 5;
}

.sync-ring {
  fill: none;
  stroke: var(--teal);
  stroke-width: 7;
  stroke-linecap: round;
  stroke-dasharray: 21 16;
}

.center-body {
  fill: #f5f7f7;
  stroke: #c8d0d5;
  stroke-width: 2;
}

.vane {
  fill: #45525a;
  stroke: #192229;
  stroke-width: 1.2;
}

.vane.open {
  fill: #6f7b82;
}

.link {
  stroke: #c7892b;
  stroke-width: 4;
  stroke-linecap: round;
}

.lever {
  stroke: #273137;
  stroke-width: 5;
  stroke-linecap: round;
}

.pin {
  fill: #fff;
  stroke: #243039;
  stroke-width: 2;
}

.support {
  fill: #eef2f3;
  stroke: #aeb9bf;
  stroke-width: 2;
}

.actuator-body {
  fill: #2b363c;
}

.actuator-rod {
  stroke: #c7892b;
  stroke-width: 9;
  stroke-linecap: round;
}

.diagram-label {
  fill: #2a353b;
  font-size: 15px;
  font-weight: 760;
}

.diagram-small {
  fill: #65737b;
  font-size: 12px;
}

@media (max-width: 980px) {
  .site-header {
    padding: 0 20px;
  }

  .nav-links {
    display: none;
  }

  .hero {
    padding-inline: 22px;
  }

  .hero-overlay {
    background:
      linear-gradient(90deg, rgba(10, 16, 20, 0.94) 0%, rgba(12, 18, 21, 0.78) 62%, rgba(12, 18, 21, 0.34) 100%),
      linear-gradient(0deg, rgba(10, 16, 20, 0.56), rgba(10, 16, 20, 0.12));
  }

  .hero-metrics,
  .scope-grid,
  .architecture-flow,
  .validation-grid,
  .calc-layout,
  .motion-layout {
    grid-template-columns: 1fr 1fr;
  }

  .control-panel {
    grid-column: 1 / -1;
  }

  .architecture-flow {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 660px) {
  .section {
    padding: 68px 20px;
  }

  .hero {
    min-height: auto;
    padding: 92px 20px 30px;
  }

  .hero-copy {
    font-size: 16px;
  }

  .hero-actions {
    display: grid;
  }

  .hero-metrics {
    display: none;
  }

  .scope-grid,
  .validation-grid,
  .calc-layout,
  .motion-layout {
    grid-template-columns: 1fr;
  }

  .motion-visual {
    min-height: 410px;
    padding: 6px;
  }

  #igvDiagram {
    min-height: 390px;
  }

  .section-head h2 {
    font-size: 32px;
  }

  .site-footer {
    display: grid;
  }
}