:root {
  color-scheme: light;
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafd;
  --color-surface: #ffffff;
  --color-surface-soft: #f1f3f4;
  --color-primary: #1a73e8;
  --color-primary-strong: #185abc;
  --color-text: #202124;
  --color-text-secondary: #666666;
  --color-border: #e8eaed;
  --shadow-low: 0 1px 2px rgba(60, 64, 67, 0.3), 0 2px 6px 2px rgba(60, 64, 67, 0.15);
  --max-width: 1184px;
  font-family: "Google Sans", "Roboto", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  letter-spacing: 0;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: "Roboto", "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

a {
  color: inherit;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.2em;
}

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

code,
pre {
  font-family: "Roboto Mono", "Cascadia Code", Consolas, monospace;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -64px;
  z-index: 20;
  padding: 8px 16px;
  border-radius: 8px;
  background: var(--color-primary);
  color: #ffffff;
  transition: top 160ms ease;
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
}

.nav-shell,
.container {
  width: min(var(--max-width), calc(100% - 32px));
  margin: 0 auto;
}

.nav-shell {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 20px;
  font-weight: 500;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 10px;
  background: var(--color-primary);
  color: #ffffff;
  font-family: "Roboto Mono", monospace;
  font-size: 14px;
  font-weight: 700;
}

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

.nav-links a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  border-radius: 100px;
  padding: 0 16px;
  color: var(--color-text-secondary);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  background: var(--color-surface-soft);
  color: var(--color-primary);
}

.menu-button {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  background: #ffffff;
  color: var(--color-text);
  cursor: pointer;
}

.menu-button span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  border-radius: 2px;
  background: currentColor;
}

.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--color-border);
  background:
    linear-gradient(180deg, rgba(26, 115, 232, 0.07), rgba(255, 255, 255, 0) 58%),
    var(--color-bg);
}

.hero::before {
  position: absolute;
  inset: 0;
  z-index: 0;
  content: "";
  background-image:
    linear-gradient(rgba(232, 234, 237, 0.72) 1px, transparent 1px),
    linear-gradient(90deg, rgba(232, 234, 237, 0.72) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(90deg, transparent, #000 18%, #000 86%, transparent);
}

.hero-asset {
  position: absolute;
  right: max(-90px, calc((100vw - var(--max-width)) / 2 - 170px));
  bottom: 54px;
  z-index: 0;
  width: min(58vw, 820px);
  opacity: 0.92;
}

.hero-inner {
  position: relative;
  z-index: 1;
  min-height: 690px;
  padding: 96px 0 88px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 24px;
  color: var(--color-primary);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 16px;
  font-weight: 500;
}

.eyebrow::before {
  width: 10px;
  height: 10px;
  border-radius: 100px;
  background: var(--color-primary);
  content: "";
}

.hero h1 {
  max-width: 610px;
  margin: 0;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: clamp(52px, 6.5vw, 84px);
  font-weight: 500;
  letter-spacing: 0;
  line-height: 1.08;
}

.hero-copy {
  max-width: 540px;
  margin: 32px 0 0;
  color: var(--color-text-secondary);
  font-size: 20px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 40px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 100px;
  padding: 0 24px;
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 16px;
  font-weight: 500;
  text-decoration: none;
  transition: background 160ms ease, box-shadow 160ms ease, color 160ms ease, transform 160ms ease;
}

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

.button-primary {
  background: var(--color-primary);
  color: #ffffff;
  box-shadow: 0 1px 2px rgba(26, 115, 232, 0.28), 0 2px 6px 2px rgba(26, 115, 232, 0.16);
}

.button-primary:hover {
  background: var(--color-primary-strong);
}

.button-secondary {
  border-color: var(--color-border);
  background: #ffffff;
  color: var(--color-primary);
}

.button-secondary:hover {
  background: #f8fafd;
}

.button-text {
  min-height: 40px;
  padding: 0 4px;
  color: var(--color-primary);
}

.signal-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-bottom: 1px solid var(--color-border);
  background: #ffffff;
}

.signal-item {
  min-height: 128px;
  padding: 24px;
  border-right: 1px solid var(--color-border);
}

.signal-item:last-child {
  border-right: 0;
}

.signal-item strong {
  display: block;
  margin-bottom: 8px;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 18px;
  font-weight: 500;
}

.signal-item span {
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.section {
  padding: 88px 0;
  background: #ffffff;
}

.section.alt {
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(280px, 0.55fr);
  gap: 48px;
  align-items: end;
  margin-bottom: 40px;
}

.section-label {
  margin: 0 0 12px;
  color: var(--color-primary);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 14px;
  font-weight: 500;
}

.section h2 {
  margin: 0;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 500;
  letter-spacing: 0;
  line-height: 1.25;
}

.section-lede {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 18px;
  line-height: 1.85;
}

.steps,
.features,
.docs-grid {
  display: grid;
  gap: 24px;
}

.steps {
  grid-template-columns: repeat(3, 1fr);
}

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

.docs-grid {
  grid-template-columns: repeat(3, 1fr);
}

.step-card,
.feature-card,
.doc-card,
.workflow-panel,
.safety-card {
  border: 1px solid var(--color-border);
  border-radius: 24px;
  background: var(--color-surface);
  box-shadow: var(--shadow-low);
}

.step-card,
.feature-card,
.doc-card,
.safety-card {
  min-height: 224px;
  padding: 32px;
}

.step-index,
.feature-kicker {
  display: inline-flex;
  min-width: 40px;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  border-radius: 100px;
  background: #e8f0fe;
  color: var(--color-primary);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-weight: 500;
}

.feature-kicker {
  padding: 0 14px;
  font-size: 13px;
}

.step-card h3,
.feature-card h3,
.doc-card h3,
.safety-card h3 {
  margin: 0 0 12px;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 24px;
  font-weight: 500;
  line-height: 1.35;
}

.step-card p,
.feature-card p,
.doc-card p,
.safety-card p {
  margin: 0;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.command-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: start;
  margin-top: 32px;
  border: 1px solid var(--color-border);
  border-radius: 24px;
  background: #f8fafd;
  box-shadow: var(--shadow-low);
}

.command-panel pre {
  margin: 0;
  padding: 24px;
  overflow-x: auto;
  color: #174ea6;
  font-size: 15px;
  line-height: 1.8;
}

.copy-button {
  min-width: 72px;
  min-height: 40px;
  margin: 16px;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  background: #ffffff;
  color: var(--color-primary);
  font: inherit;
  font-weight: 500;
  cursor: pointer;
}

.workflow {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.75fr);
  gap: 24px;
}

.workflow-panel {
  padding: 32px;
}

.workflow-panel h3 {
  margin: 0 0 24px;
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 28px;
  font-weight: 500;
}

.flow-list {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.flow-list li {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 16px;
  align-items: start;
}

.flow-dot {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border-radius: 100px;
  background: #e8f0fe;
  color: var(--color-primary);
  font-family: "Google Sans", sans-serif;
  font-weight: 500;
}

.flow-list strong {
  display: block;
  margin-bottom: 4px;
  color: var(--color-text);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-weight: 500;
}

.flow-list span {
  color: var(--color-text-secondary);
  line-height: 1.75;
}

.doc-card a {
  display: inline-flex;
  margin-top: 20px;
  color: var(--color-primary);
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-weight: 500;
}

.cta-band {
  padding: 80px 0;
  background: #ffffff;
}

.cta-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  border: 1px solid var(--color-border);
  border-radius: 32px;
  padding: 40px;
  background: #e8f0fe;
}

.cta-shell h2 {
  margin: 0 0 8px;
  font-family: "Google Sans", "Noto Sans SC", sans-serif;
  font-size: 36px;
  font-weight: 500;
  line-height: 1.3;
}

.cta-shell p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 18px;
  line-height: 1.75;
}

.site-footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
  background: #ffffff;
}

.footer-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--color-text-secondary);
  font-size: 14px;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  color: var(--color-primary);
}

@media (max-width: 1024px) {
  .hero-asset {
    right: -190px;
    width: 720px;
    opacity: 0.34;
  }

  .section-head,
  .workflow {
    grid-template-columns: 1fr;
  }

  .steps,
  .features,
  .docs-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .signal-item:nth-child(2) {
    border-right: 0;
  }
}

@media (max-width: 720px) {
  .menu-button {
    display: block;
  }

  .nav-links {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 8px;
    border: 1px solid var(--color-border);
    border-radius: 24px;
    background: #ffffff;
    box-shadow: var(--shadow-low);
  }

  .nav-links[data-open="true"] {
    display: flex;
  }

  .hero-inner {
    min-height: 620px;
    padding: 72px 0 64px;
  }

  .hero-asset {
    right: -292px;
    bottom: 24px;
    width: 650px;
    opacity: 0.2;
  }

  .hero h1 {
    font-size: 48px;
  }

  .hero-copy {
    font-size: 18px;
  }

  .hero-actions,
  .cta-shell,
  .footer-shell {
    align-items: flex-start;
    flex-direction: column;
  }

  .signal-strip,
  .steps,
  .features,
  .docs-grid {
    grid-template-columns: 1fr;
  }

  .signal-item {
    border-right: 0;
    border-bottom: 1px solid var(--color-border);
  }

  .signal-item:last-child {
    border-bottom: 0;
  }

  .section {
    padding: 64px 0;
  }

  .step-card,
  .feature-card,
  .doc-card,
  .safety-card,
  .workflow-panel {
    padding: 24px;
  }

  .command-panel {
    grid-template-columns: 1fr;
  }

  .copy-button {
    width: calc(100% - 32px);
    margin-top: 0;
  }
}