:root {
  --canvas: #f4f7f8;
  --surface: #ffffff;
  --surface-soft: #eef5f2;
  --surface-code: #18232a;
  --ink: #172126;
  --muted: #5a6870;
  --line: #d6dee2;
  --line-strong: #b8c7ce;
  --accent: #0f6c5c;
  --accent-strong: #0a5649;
  --accent-soft: #e3f1ed;
  --blue: #405ea8;
  --amber: #a66a00;
  --shadow: 0 10px 28px rgba(23, 33, 38, 0.08);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: "Segoe UI Variable Text", "Segoe UI", Arial, sans-serif;
  overflow-x: hidden;
}

a {
  color: var(--accent-strong);
}

a:hover,
a:focus-visible {
  color: var(--blue);
}

.layout-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 304px minmax(0, 1fr);
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 1.35rem 1rem;
  border-right: 1px solid var(--line);
  background: var(--surface);
  overflow-y: auto;
}

.brand-block h1,
.page-title,
.doc-content h1,
.doc-content h2,
.doc-content h3 {
  font-family: inherit;
  letter-spacing: 0;
}

.brand-block h1 {
  margin: 0;
  font-size: 1.35rem;
  line-height: 1.2;
}

.eyebrow,
.page-kicker,
.hero-kicker,
.search-label {
  margin: 0 0 0.45rem;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.tagline,
.sidebar-note,
.hero-copy p {
  color: var(--muted);
  line-height: 1.55;
}

.tagline {
  margin: 0.55rem 0 0;
  font-size: 0.94rem;
}

.lang-switch {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.2rem;
  margin: 1rem 0;
  padding: 0.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafb;
}

.lang-option {
  min-height: 2.25rem;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  font-weight: 800;
}

.lang-option:hover,
.lang-option:focus-visible {
  background: var(--surface-soft);
  color: var(--ink);
  outline: 2px solid transparent;
}

.lang-option.active {
  background: var(--accent);
  color: #ffffff;
}

.nav-filter {
  width: 100%;
  margin-bottom: 1rem;
  padding: 0.75rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
}

.nav-filter:focus {
  border-color: var(--accent);
  outline: 3px solid var(--accent-soft);
}

.page-nav {
  display: grid;
  gap: 0.5rem;
}

.nav-section {
  display: grid;
  gap: 0.35rem;
}

.nav-section + .nav-section {
  margin-top: 0.85rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--line);
}

.nav-section-title {
  margin: 0 0 0.1rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.page-link {
  display: block;
  padding: 0.72rem 0.78rem;
  border: 1px solid transparent;
  border-left: 3px solid transparent;
  border-radius: var(--radius);
  color: inherit;
  text-decoration: none;
  transition: border-color 140ms ease, background 140ms ease;
}

.page-link:hover,
.page-link:focus-visible {
  border-color: var(--line-strong);
  border-left-color: var(--accent);
  background: #f8fbfa;
  outline: none;
}

.page-link.active {
  border-color: #bfded6;
  border-left-color: var(--accent);
  background: var(--accent-soft);
}

.page-link strong {
  display: block;
  margin-bottom: 0.12rem;
  font-size: 0.98rem;
}

.page-link span {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.35;
}

.nav-empty {
  margin: 0;
  padding: 0.85rem;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  color: var(--muted);
  line-height: 1.5;
}

.sidebar-note {
  margin-top: 1rem;
  padding: 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafb;
  font-size: 0.92rem;
}

.content-shell {
  min-width: 0;
  padding: 1.25rem 2rem 4rem;
}

.topbar {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1rem;
}

.topbar > div {
  min-width: 0;
  flex: 1;
}

.nav-toggle {
  display: none;
  min-height: 2.4rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  padding: 0.6rem 0.85rem;
  font: inherit;
  font-weight: 800;
}

.page-title {
  margin: 0;
  font-size: 2rem;
  line-height: 1.2;
}

.page-kicker {
  line-height: 1.35;
  overflow-wrap: anywhere;
}

.hero-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.9fr);
  gap: 1rem;
  margin-bottom: 1rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-copy p:last-child {
  margin-bottom: 0;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafb;
}

.hero-metrics div {
  padding: 0.8rem;
}

.hero-metrics div + div {
  border-left: 1px solid var(--line);
}

.hero-metrics strong {
  display: block;
  font-size: 1rem;
}

.hero-metrics span {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.35;
}

.doc-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 1rem;
  align-items: start;
}

.doc-content {
  min-width: 0;
  overflow: hidden;
  padding: 1.6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  line-height: 1.7;
}

.doc-content h1 {
  margin-top: 0;
  font-size: 2rem;
  line-height: 1.2;
}

.doc-content h2 {
  margin-top: 2rem;
  padding-top: 0.2rem;
  font-size: 1.45rem;
  line-height: 1.25;
}

.doc-content h3 {
  margin-top: 1.5rem;
  font-size: 1.16rem;
  line-height: 1.3;
}

.doc-content h2,
.doc-content h3 {
  scroll-margin-top: 1.5rem;
}

.doc-content img {
  max-width: 100%;
  height: auto;
}

.figure-scroll {
  margin: 1.2rem 0;
  padding: 0.75rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcfd;
}

.figure-scroll img {
  display: block;
  border: 0;
  border-radius: 6px;
}

.doc-content table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.table-scroll {
  margin: 1.2rem 0;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.table-scroll table {
  margin: 0;
  min-width: 640px;
  border: 0;
}

.doc-content th,
.doc-content td {
  padding: 0.68rem 0.75rem;
  border: 1px solid var(--line);
  vertical-align: top;
}

.doc-content th {
  background: var(--surface-soft);
}

.doc-content pre,
.doc-content code {
  font-family: Consolas, "Cascadia Mono", monospace;
}

.doc-content pre {
  padding: 1rem;
  overflow-x: auto;
  border-radius: var(--radius);
  background: var(--surface-code);
  color: #f8fafc;
}

.doc-content :not(pre) > code {
  padding: 0.1rem 0.35rem;
  border-radius: 6px;
  background: #eaf2f4;
}

.doc-content blockquote {
  margin: 1rem 0;
  padding: 0.35rem 1rem;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
}

.doc-content hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 2rem 0;
}

.mermaid-shell {
  margin: 1.2rem 0;
  padding: 0.9rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcfd;
}

.page-outline {
  position: sticky;
  top: 1rem;
  max-height: calc(100vh - 2rem);
  overflow-y: auto;
}

.outline-card {
  padding: 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.outline-title {
  margin: 0 0 0.7rem;
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.outline-nav {
  display: grid;
  gap: 0.25rem;
}

.outline-link {
  padding: 0.28rem 0.35rem;
  border-radius: 6px;
  color: var(--ink);
  text-decoration: none;
  line-height: 1.4;
}

.outline-link.h3 {
  padding-left: 0.9rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.outline-link:hover,
.outline-link:focus-visible {
  background: var(--surface-soft);
  color: var(--accent-strong);
  outline: none;
}

.sidebar-backdrop {
  display: none;
}

@media (max-width: 1200px) {
  .doc-layout {
    grid-template-columns: 1fr;
  }

  .page-outline {
    position: static;
    max-height: none;
  }
}

@media (max-width: 960px) {
  .layout-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(88vw, 320px);
    transform: translateX(-100%);
    transition: transform 180ms ease;
    z-index: 20;
    box-shadow: 14px 0 30px rgba(23, 33, 38, 0.18);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-backdrop {
    position: fixed;
    inset: 0;
    display: block;
    background: rgba(23, 33, 38, 0.42);
    z-index: 15;
  }

  .sidebar-backdrop[hidden] {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
  }

  .topbar {
    flex-wrap: wrap;
  }

  .content-shell {
    padding: 1rem 1rem 3rem;
  }

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

  .hero-metrics div + div {
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 720px) {
  .page-title,
  .doc-content h1 {
    font-size: 1.55rem;
  }

  .doc-content {
    padding: 1rem;
  }

  .doc-content h2 {
    font-size: 1.28rem;
  }

  .figure-scroll img[src$=".svg"] {
    width: 880px;
    max-width: none;
  }
}