:root {
  color-scheme: light;
  --paper: #f4f2ea;
  --paper-strong: #e7e4d8;
  --ink: #181a17;
  --muted: #5c6259;
  --line: #c8c6ba;
  --charcoal: #191c18;
  --charcoal-soft: #242822;
  --dark-text: #f4f6ed;
  --dark-muted: #c3c9bc;
  --lime: #c9ff52;
  --lime-ink: #173000;
  --link: #365f00;
  --focus: #547b00;
  --danger: #8b2d24;
  --lime-soft: #e5ffac;
  --radius-sm: 0.45rem;
  --radius-md: 1rem;
  --content: 72rem;
  --reading: 46rem;
  --shadow: 0 1.25rem 4rem rgba(24, 26, 23, 0.12);
  --font-display: Baskerville, "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --font-body: "Avenir Next", Avenir, "Helvetica Neue", Helvetica, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-width: 18rem;
  margin: 0;
  background:
    linear-gradient(rgba(24, 26, 23, 0.035) 1px, transparent 1px),
    var(--paper);
  background-size: 100% 2rem;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--link);
  -webkit-tap-highlight-color: rgba(54, 95, 0, 0.18);
  text-decoration-thickness: 0.1em;
  text-underline-offset: 0.2em;
  touch-action: manipulation;
}

a:hover {
  text-decoration-thickness: 0.16em;
}

a:focus-visible,
summary:focus-visible,
video:focus-visible {
  border-radius: 0.2rem;
  outline: 3px solid var(--focus);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.7rem 1rem;
  border-radius: var(--radius-sm);
  background: var(--lime);
  color: var(--lime-ink);
  font-weight: 700;
  transform: translateY(-180%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header,
.site-footer,
.page-shell {
  width: min(calc(100% - 2rem), var(--content));
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: 5.5rem;
  border-bottom: 1px solid var(--line);
}

.site-header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--ink);
  font-weight: 750;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.brand-mark {
  display: block;
  flex: 0 0 2.35rem;
  width: 2.35rem;
  height: 2.35rem;
  user-select: none;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  color: var(--ink);
  font-size: 0.92rem;
  font-weight: 650;
  text-decoration: none;
  transition: background-color 160ms ease, color 160ms ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  background: var(--charcoal);
  color: var(--dark-text);
}

.language-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 3.25rem;
  min-height: 2.75rem;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink);
  font-size: 0.88rem;
  font-weight: 750;
  text-decoration: none;
  transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}

.language-link:hover {
  border-color: var(--charcoal);
  background: var(--charcoal);
  color: var(--dark-text);
}

.page-shell {
  padding-block: clamp(2.75rem, 7vw, 6.5rem);
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(15rem, 0.55fr);
  gap: clamp(2rem, 7vw, 7rem);
  overflow: hidden;
  padding: clamp(2rem, 6vw, 5.5rem);
  border-radius: var(--radius-md);
  background: var(--charcoal);
  box-shadow: var(--shadow);
  color: var(--dark-text);
}

.hero::after {
  position: absolute;
  right: -6rem;
  bottom: -9rem;
  width: 14rem;
  height: 14rem;
  border: 3.5rem solid var(--lime);
  border-radius: 50%;
  content: "";
  opacity: 0.96;
}

.hero-copy,
.hero-note {
  position: relative;
  z-index: 1;
}

.eyebrow {
  margin: 0 0 1rem;
  color: inherit;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin-top: 0;
  color: inherit;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.05;
  text-wrap: balance;
}

h1 {
  max-width: 12ch;
  margin-bottom: 1.35rem;
  font-size: clamp(3rem, 8vw, 7.6rem);
}

h2 {
  margin-bottom: 1rem;
  font-size: clamp(2rem, 4.2vw, 3.75rem);
}

h3 {
  margin-bottom: 0.6rem;
  font-size: 1.45rem;
}

.hero-lede {
  max-width: 39rem;
  margin: 0;
  color: var(--dark-muted);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 1.4rem 0 0;
  color: var(--lime-soft);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hero-note {
  align-self: end;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(244, 246, 237, 0.35);
  color: var(--dark-muted);
  font-size: 0.95rem;
}

.hero-note strong {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--lime);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.principles,
.detail-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(3.5rem, 8vw, 7rem);
  border: 1px solid var(--line);
  background: var(--line);
}

.product-demo {
  display: grid;
  grid-template-columns: minmax(15rem, 0.62fr) minmax(0, 1.38fr);
  gap: clamp(2rem, 6vw, 5rem);
  align-items: center;
  margin-top: clamp(4rem, 9vw, 8rem);
}

.demo-copy h2 {
  max-width: 10ch;
}

.demo-copy > p:not(.eyebrow) {
  max-width: 34rem;
  color: var(--muted);
  font-size: 1.08rem;
}

.signal-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.signal-list li {
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper-strong);
  font-size: 0.86rem;
  font-weight: 700;
}

.demo-frame {
  min-width: 0;
  margin: 0;
  padding: clamp(0.55rem, 1.2vw, 0.9rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--charcoal);
  box-shadow: var(--shadow);
}

.demo-frame video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: calc(var(--radius-md) - 0.4rem);
  background: #10120f;
}

.demo-frame figcaption {
  padding: 0.75rem 0.35rem 0.15rem;
  color: var(--dark-muted);
  font-size: 0.82rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.feature-card {
  min-width: 0;
  padding: clamp(1.5rem, 3vw, 2.5rem);
  background: var(--paper);
}

.feature-card h3 {
  margin-bottom: 0.75rem;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
}

.feature-index {
  display: inline-block;
  margin-bottom: 2rem;
  color: var(--link);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
}

.safety-band {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 7vw, 7rem);
  margin-top: clamp(4.5rem, 10vw, 9rem);
  padding: clamp(2rem, 5vw, 4.5rem);
  border-radius: var(--radius-md);
  background: var(--charcoal);
  color: var(--dark-text);
}

.safety-band h2 {
  max-width: 12ch;
  margin-bottom: 0;
}

.safety-band > div:last-child {
  align-self: end;
}

.safety-band > div:last-child > p {
  margin: 0;
  color: var(--dark-muted);
  font-size: 1.05rem;
}

.text-link-on-dark {
  color: var(--lime);
}

.closing-cta {
  max-width: 48rem;
  margin: clamp(4.5rem, 10vw, 9rem) auto 0;
  text-align: center;
}

.closing-cta h2 {
  margin-inline: auto;
}

.closing-cta > p:not(.eyebrow) {
  max-width: 39rem;
  margin-inline: auto;
  color: var(--muted);
  font-size: 1.08rem;
}

.principle,
.detail-card {
  min-width: 0;
  padding: clamp(1.5rem, 3vw, 2.5rem);
  background: var(--paper);
}

.principle-index {
  display: inline-block;
  margin-bottom: 2rem;
  color: var(--link);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
}

.principle p,
.detail-card p {
  margin-bottom: 0;
  color: var(--muted);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 0.6fr) minmax(0, 1.4fr);
  gap: 2rem;
  align-items: end;
  margin-top: clamp(4.5rem, 10vw, 9rem);
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
}

.section-heading p {
  max-width: 42rem;
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.mode-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.mode-list li {
  display: grid;
  grid-template-columns: minmax(11rem, 0.55fr) minmax(0, 1.45fr);
  gap: 2rem;
  padding-block: 1.4rem;
  border-bottom: 1px solid var(--line);
}

.mode-list strong {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.mode-list span {
  color: var(--muted);
}

.text-link {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  margin-top: 1.5rem;
  font-weight: 750;
}

.document {
  max-width: var(--reading);
  margin-inline: auto;
  overflow-wrap: break-word;
}

[id] {
  scroll-margin-top: 1rem;
}

.document-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 3px solid var(--ink);
}

.document-header h1 {
  max-width: none;
  margin-bottom: 1rem;
  font-size: clamp(2.8rem, 7vw, 5.75rem);
}

.document-header p {
  max-width: 39rem;
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.document section {
  padding-block: 1.5rem;
  border-bottom: 1px solid var(--line);
}

.document section:last-of-type {
  border-bottom: 0;
}

.document h2 {
  margin-bottom: 0.75rem;
  font-size: clamp(1.65rem, 4vw, 2.45rem);
}

.document p,
.document ul,
.document ol,
.document dl {
  margin-top: 0.75rem;
}

.document li + li {
  margin-top: 0.55rem;
}

.document dt {
  margin-top: 1rem;
  font-weight: 750;
}

.document dd {
  margin-left: 0;
  color: var(--muted);
}

.notice {
  margin-block: 1.5rem;
  padding: 1.25rem 1.4rem;
  border-left: 0.4rem solid var(--lime-ink);
  background: var(--paper-strong);
}

.notice strong {
  display: block;
  margin-bottom: 0.25rem;
}

.placeholder {
  display: inline-block;
  max-width: 100%;
  padding: 0.08rem 0.4rem;
  border: 1px dashed var(--danger);
  border-radius: 0.25rem;
  color: var(--danger);
  font-family: var(--font-mono);
  font-size: 0.9em;
  font-weight: 700;
  overflow-wrap: anywhere;
}

code {
  padding: 0.1rem 0.35rem;
  border-radius: 0.25rem;
  background: var(--paper-strong);
  font-family: var(--font-mono);
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem 2rem;
  padding-block: 2rem 3.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer p {
  margin: 0;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}

@media (max-width: 48rem) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    padding-block: 1rem;
  }

  .hero,
  .product-demo,
  .safety-band,
  .section-heading,
  .mode-list li {
    grid-template-columns: 1fr;
  }

  .hero::after {
    right: -7rem;
    bottom: -11rem;
  }

  .principles,
  .detail-grid,
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .hero-note {
    max-width: 17rem;
  }
}

@media (max-width: 28rem) {
  .site-header,
  .site-footer,
  .page-shell {
    width: min(calc(100% - 1.25rem), var(--content));
  }

  .site-nav ul {
    gap: 0;
  }

  .site-header-actions {
    width: 100%;
    align-items: flex-start;
    justify-content: space-between;
  }

  .site-nav {
    min-width: 0;
  }

  .site-nav a {
    padding-inline: 0.6rem;
  }

  .hero {
    padding: 1.5rem;
  }

  h1 {
    font-size: clamp(2.75rem, 15vw, 4.5rem);
  }
}

:lang(zh-CN) body,
body:lang(zh-CN) {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

:lang(zh-CN) h1,
:lang(zh-CN) h2,
:lang(zh-CN) h3 {
  font-family: "Songti SC", STSong, "Noto Serif CJK SC", serif;
  letter-spacing: -0.02em;
}

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

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

@media print {
  body {
    background: #ffffff;
    color: #000000;
  }

  .site-header,
  .site-footer,
  .skip-link {
    display: none;
  }

  .page-shell {
    width: 100%;
    padding: 0;
  }

  a {
    color: inherit;
  }
}