:root {
  color-scheme: light;
  --page-bg: #ffffff;
  --page-surface: #f7f8f9;
  --page-ink: #192945;
  --page-soft-ink: #5c6c83;
  --page-muted: #91a0b4;
  --page-line: #e7ebf0;
  --page-blue: #3179c7;
  --page-blue-soft: #edf5ff;
  --page-shadow: 0 18px 55px rgba(28, 55, 86, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --page-bg: #101318;
    --page-surface: #181e26;
    --page-ink: #f1f5fa;
    --page-soft-ink: #bbc7d4;
    --page-muted: #8999ae;
    --page-line: #303b48;
    --page-blue: #80b8fb;
    --page-blue-soft: #21354e;
    --page-shadow: 0 18px 55px rgba(0, 0, 0, 0.28);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

body {
  min-width: 320px;
  margin: 0;
  background: var(--page-bg);
  color: var(--page-ink);
  font-family: Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--page-blue);
  text-underline-offset: 4px;
}

a:focus-visible {
  border-radius: 3px;
  outline: 2px solid var(--page-blue);
  outline-offset: 4px;
}

.public-page {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

.public-header,
.public-main,
.public-footer {
  width: min(1080px, calc(100% - 56px));
  margin-right: auto;
  margin-left: auto;
}

.public-header {
  display: flex;
  min-height: 78px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--page-line);
}

.public-brand {
  display: inline-flex;
  min-width: 0;
  align-items: center;
  gap: 10px;
  color: var(--page-ink);
  text-decoration: none;
}

.public-brand img {
  width: 34px;
  height: 34px;
  object-fit: contain;
}

.public-brand-copy {
  display: grid;
  line-height: 1.25;
}

.public-brand-copy strong {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.7px;
}

.public-brand-copy small {
  color: var(--page-muted);
  font-size: 10px;
  letter-spacing: 0.02em;
}

.public-nav,
.public-footer nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 22px;
}

.public-nav a,
.public-footer a {
  color: var(--page-soft-ink);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
}

.public-nav a:hover,
.public-footer a:hover {
  color: var(--page-blue);
  text-decoration: underline;
}

.public-main {
  flex: 1 0 auto;
  padding: 72px 0 88px;
}

.public-hero {
  max-width: 820px;
  padding: 18px 0 56px;
}

.public-eyebrow {
  margin: 0 0 18px;
  color: var(--page-blue);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.public-hero h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(38px, 6.4vw, 68px);
  font-weight: 780;
  letter-spacing: -0.065em;
  line-height: 1.16;
}

.public-hero h1 span {
  color: var(--page-blue);
}

.public-lead {
  max-width: 720px;
  margin: 22px 0 0;
  color: var(--page-soft-ink);
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.9;
}

.public-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 28px;
}

.public-action-primary {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid var(--page-blue);
  border-radius: 12px;
  background: var(--page-blue);
  color: var(--page-bg);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.public-action-primary:hover {
  filter: brightness(0.96);
}

.public-action-secondary {
  font-size: 13px;
  font-weight: 650;
}

.public-section {
  margin-top: 38px;
  padding-top: 34px;
  border-top: 1px solid var(--page-line);
}

.public-section h2 {
  margin: 0;
  font-size: clamp(23px, 3vw, 30px);
  font-weight: 740;
  letter-spacing: -0.04em;
  line-height: 1.35;
}

.public-section > p {
  max-width: 720px;
  margin: 14px 0 0;
  color: var(--page-soft-ink);
}

.learning-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
}

.learning-steps li {
  position: relative;
  min-width: 0;
  padding: 22px 24px 0 0;
  border-top: 1px solid var(--page-line);
}

.learning-steps li::before {
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border: 2px solid var(--page-bg);
  border-radius: 50%;
  background: var(--page-blue);
  box-shadow: 0 0 0 1px var(--page-blue);
  content: "";
}

.learning-steps .step-label {
  display: block;
  margin-bottom: 10px;
  color: var(--page-blue);
  font-size: 11px;
  font-weight: 780;
  letter-spacing: 0.08em;
}

.learning-steps h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 730;
}

.learning-steps p {
  margin: 8px 0 0;
  color: var(--page-soft-ink);
  font-size: 14px;
  line-height: 1.85;
}

.principle-block {
  display: grid;
  grid-template-columns: minmax(180px, 0.8fr) minmax(0, 1.2fr);
  gap: 48px;
  align-items: start;
}

.principle-block p {
  max-width: 650px;
  margin: 0;
  color: var(--page-soft-ink);
}

.docs-hero {
  max-width: 780px;
  padding-bottom: 34px;
}

.docs-layout {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 56px;
  align-items: start;
  margin-top: 14px;
}

.docs-index {
  position: sticky;
  top: 28px;
  display: grid;
  gap: 5px;
  padding: 14px 0;
  border-top: 1px solid var(--page-line);
  border-bottom: 1px solid var(--page-line);
}

.docs-index strong {
  margin: 0 0 6px;
  color: var(--page-muted);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.docs-index a {
  padding: 5px 0;
  color: var(--page-soft-ink);
  font-size: 13px;
  text-decoration: none;
}

.docs-index a:hover {
  color: var(--page-blue);
}

.docs-article section {
  padding: 0 0 32px;
  margin: 0 0 32px;
  border-bottom: 1px solid var(--page-line);
  scroll-margin-top: 24px;
}

.docs-article section:last-child {
  margin-bottom: 0;
  border-bottom: 0;
}

.docs-article h2 {
  margin: 0;
  font-size: clamp(21px, 3vw, 27px);
  font-weight: 740;
  letter-spacing: -0.04em;
  line-height: 1.4;
}

.docs-article h3 {
  margin: 22px 0 5px;
  font-size: 16px;
  font-weight: 730;
}

.docs-article p,
.docs-article li {
  color: var(--page-soft-ink);
  font-size: 14px;
  line-height: 1.9;
}

.docs-article p {
  margin: 12px 0 0;
}

.docs-article ol,
.docs-article ul {
  display: grid;
  gap: 8px;
  margin: 14px 0 0;
  padding-left: 22px;
}

.docs-article li strong {
  color: var(--page-ink);
}

.public-note {
  margin-top: 18px;
  padding: 14px 16px;
  border-left: 3px solid var(--page-blue);
  background: var(--page-blue-soft);
  color: var(--page-soft-ink);
  font-size: 13px;
  line-height: 1.8;
}

.public-footer {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 18px 0 24px;
  border-top: 1px solid var(--page-line);
}

.public-footer small {
  color: var(--page-muted);
  font-size: 11px;
}

@media (max-width: 700px) {
  .public-header,
  .public-main,
  .public-footer {
    width: calc(100% - 36px);
  }

  .public-header {
    min-height: 68px;
    gap: 14px;
  }

  .public-brand-copy small {
    display: none;
  }

  .public-nav,
  .public-footer nav {
    gap: 14px;
  }

  .public-nav a,
  .public-footer a {
    font-size: 12px;
  }

  .public-main {
    padding: 42px 0 60px;
  }

  .public-hero {
    padding: 14px 0 36px;
  }

  .learning-steps {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .learning-steps li {
    padding: 18px 0 0;
  }

  .principle-block,
  .docs-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .docs-index {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 16px;
    padding: 12px 0;
  }

  .docs-index strong {
    width: 100%;
  }

  .public-footer {
    min-height: 0;
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }
}

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