:root {
  color-scheme: light;
  --paper: #ffffff;
  --soft: #f5f7f5;
  --soft-blue: #f2f6fb;
  --ink: #171b1a;
  --muted: #68716e;
  --line: #dfe4e1;
  --signal: #07856f;
  --echo: #3e7fd6;
  --warm: #d55e43;
  --amber: #b57d08;
  --max: 1120px;
  --nav-h: 58px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: 0;
}

body[data-language="en"] .lang-zh,
body[data-language="zh"] .lang-en {
  display: none !important;
}

a {
  color: inherit;
}

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

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

.site-nav {
  position: sticky;
  z-index: 50;
  top: 0;
  height: var(--nav-h);
  border-bottom: 1px solid rgba(23, 27, 26, 0.1);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.nav-inner {
  width: min(calc(100% - 40px), var(--max));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 720;
  white-space: nowrap;
}

.brand-link img {
  width: 28px;
  height: 28px;
}

.primary-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 4px;
}

.primary-nav a {
  padding: 7px 12px;
  color: #414946;
  text-decoration: none;
  font-size: 14px;
  border-radius: 6px;
}

.primary-nav a:hover,
.primary-nav a[aria-current="page"] {
  background: #eef1ef;
  color: var(--ink);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.language-toggle,
.menu-toggle {
  height: 34px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  border-radius: 6px;
  cursor: pointer;
}

.language-toggle {
  min-width: 48px;
  padding: 0 10px;
  font-weight: 650;
}

.menu-toggle {
  display: none;
  width: 36px;
  padding: 0;
  align-items: center;
  justify-content: center;
}

.menu-toggle span,
.menu-toggle::before,
.menu-toggle::after {
  width: 16px;
  height: 1px;
  background: var(--ink);
  content: "";
}

.menu-toggle span {
  margin: 4px 0;
}

.hero {
  position: relative;
  min-height: min(66vh, 610px);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}

.phase-field {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero::after {
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.68);
  content: "";
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(calc(100% - 40px), var(--max));
  min-height: min(66vh, 610px);
  margin: 0 auto;
  padding: 56px 0 50px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--signal);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

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

.hero h1 {
  max-width: 760px;
  margin-bottom: 16px;
  font-size: 72px;
  line-height: 1;
  font-weight: 760;
}

.hero-lead {
  max-width: 680px;
  margin-bottom: 10px;
  font-size: 26px;
  line-height: 1.3;
  font-weight: 610;
}

.hero-support {
  max-width: 640px;
  margin-bottom: 24px;
  color: #515a56;
  font-size: 16px;
}

.hero-actions,
.inline-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.button {
  min-height: 42px;
  padding: 9px 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid var(--ink);
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font-weight: 680;
}

.button.secondary {
  border-color: rgba(23, 27, 26, 0.24);
  background: rgba(255, 255, 255, 0.76);
  color: var(--ink);
}

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

.section {
  border-bottom: 1px solid var(--line);
}

.section.soft {
  background: var(--soft);
}

.section.blue {
  background: var(--soft-blue);
}

.section-inner {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
  padding: 62px 0;
}

.section-heading {
  max-width: 820px;
  margin-bottom: 34px;
}

.section-heading h2,
.page-header h1 {
  margin-bottom: 14px;
  font-size: 46px;
  line-height: 1.12;
  font-weight: 730;
}

.section-heading p,
.page-header .lead {
  max-width: 720px;
  color: var(--muted);
  font-size: 17px;
}

.stage-loop {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  border-top: 1px solid #ccd4d0;
  border-bottom: 1px solid #ccd4d0;
}

.stage-loop span {
  min-height: 80px;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-right: 1px solid #ccd4d0;
  font-size: 14px;
  font-weight: 660;
}

.stage-loop span:last-child {
  border-right: 0;
}

.stage-loop small {
  color: var(--signal);
  font-size: 11px;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 52px;
  align-items: start;
}

.split-copy h2 {
  margin-bottom: 18px;
  font-size: 44px;
  line-height: 1.14;
}

.split-copy p {
  color: var(--muted);
  font-size: 17px;
}

.principle-list,
.fact-list,
.timeline,
.method-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.principle-list li,
.fact-list li {
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.principle-list li:last-child,
.fact-list li:last-child {
  border-bottom: 1px solid var(--line);
}

.principle-list strong,
.fact-list strong {
  display: block;
  margin-bottom: 5px;
  font-size: 18px;
}

.principle-list span,
.fact-list span {
  color: var(--muted);
}

.product-shot {
  overflow: hidden;
  border: 1px solid #d7ddda;
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 24px 60px rgba(19, 35, 30, 0.11);
}

.product-shot img {
  width: 100%;
}

.shot-caption {
  padding: 14px 18px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
}

.metric {
  padding: 28px 22px 0 0;
  border-right: 1px solid var(--line);
}

.metric:last-child {
  border-right: 0;
  padding-left: 22px;
}

.metric strong {
  display: block;
  font-size: 30px;
  line-height: 1.2;
}

.metric span {
  color: var(--muted);
  font-size: 14px;
}

.page-header {
  border-bottom: 1px solid var(--line);
}

.page-header-inner {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
  padding: 68px 0 54px;
}

.page-header h1 {
  max-width: 920px;
}

.method-list {
  counter-reset: method;
}

.method-list li {
  counter-increment: method;
  padding: 28px 0;
  display: grid;
  grid-template-columns: 72px minmax(0, 0.75fr) minmax(260px, 1.25fr);
  gap: 28px;
  border-top: 1px solid var(--line);
}

.method-list li::before {
  content: "0" counter(method);
  color: var(--signal);
  font-size: 13px;
  font-weight: 800;
}

.method-list h3 {
  margin-bottom: 6px;
  font-size: 23px;
}

.method-list p {
  margin-bottom: 0;
  color: var(--muted);
}

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

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

.boundary-table th {
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
}

.status-label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--signal);
  font-size: 13px;
  font-weight: 760;
}

.status-label::before {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  content: "";
}

.timeline li {
  padding: 24px 0;
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 28px;
  border-top: 1px solid var(--line);
}

.timeline time {
  color: var(--muted);
  font-size: 14px;
}

.timeline h3 {
  margin-bottom: 6px;
  font-size: 22px;
}

.timeline p {
  margin-bottom: 0;
  color: var(--muted);
}

.site-footer {
  background: #171b1a;
  color: #fff;
}

.footer-inner {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
  padding: 46px 0 30px;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  gap: 40px;
  align-items: flex-start;
}

.footer-title {
  max-width: 520px;
  font-size: 24px;
  line-height: 1.25;
  font-weight: 680;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.footer-links a {
  color: #cdd5d1;
  text-decoration: none;
}

.footer-bottom {
  margin-top: 38px;
  padding-top: 18px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid #343b38;
  color: #aeb8b3;
  font-size: 13px;
}

@media (max-width: 860px) {
  .nav-inner {
    width: min(calc(100% - 28px), var(--max));
  }

  .menu-toggle {
    display: inline-flex;
    flex-direction: column;
  }

  .primary-nav {
    position: fixed;
    inset: var(--nav-h) 0 auto;
    padding: 12px 14px 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    border-bottom: 1px solid var(--line);
    background: #fff;
  }

  body.menu-open .primary-nav {
    display: flex;
  }

  .primary-nav a {
    padding: 11px 12px;
  }

  .hero,
  .hero-inner {
    min-height: 560px;
  }

  .hero-inner {
    padding-top: 52px;
  }

  .hero h1 {
    font-size: 56px;
  }

  .hero-lead {
    font-size: 23px;
  }

  .section-heading h2,
  .page-header h1,
  .split-copy h2 {
    font-size: 38px;
  }

  .stage-loop {
    grid-template-columns: repeat(4, 1fr);
  }

  .stage-loop span:nth-child(4) {
    border-right: 0;
  }

  .stage-loop span:nth-child(n + 5) {
    border-top: 1px solid #ccd4d0;
  }

  .split {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .method-list li {
    grid-template-columns: 46px 1fr;
  }

  .method-list p {
    grid-column: 2;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 15px;
  }

  .brand-link span {
    max-width: 138px;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .nav-actions {
    margin-left: auto;
  }

  .hero h1 {
    font-size: 42px;
  }

  .hero-lead {
    font-size: 20px;
  }

  .section-heading h2,
  .page-header h1,
  .split-copy h2 {
    font-size: 34px;
  }

  .section-inner,
  .page-header-inner {
    width: min(calc(100% - 28px), var(--max));
    padding: 48px 0;
  }

  .stage-loop {
    grid-template-columns: repeat(2, 1fr);
  }

  .stage-loop span:nth-child(even) {
    border-right: 0;
  }

  .stage-loop span:nth-child(n + 3) {
    border-top: 1px solid #ccd4d0;
  }

  .metrics {
    grid-template-columns: 1fr;
  }

  .metric,
  .metric:last-child {
    padding: 20px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .timeline li {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .boundary-table {
    display: block;
    overflow-x: auto;
  }

  .footer-top,
  .footer-bottom {
    flex-direction: column;
  }
}

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

  .button:hover {
    transform: none;
  }
}