:root {
  color-scheme: light;
  --bg: #ffffff;
  --panel: #f6f8fa;
  --panel-2: #eef2f7;
  --text: #1f2328;
  --muted: #59636e;
  --border: #d0d7de;
  --link: #0969da;
  --link-hover: #0550ae;
  --code-bg: #f6f8fa;
  --header-bg: rgba(255,255,255,0.92);
  --accent-bg: #dbeafe;
  --accent-text: #0b3d91;
  --max-width: 78rem;
  --sidebar-width: 18rem;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #0d1117;
    --panel: #161b22;
    --panel-2: #21262d;
    --text: #e6edf3;
    --muted: #9da7b3;
    --border: #30363d;
    --link: #58a6ff;
    --link-hover: #79c0ff;
    --code-bg: #161b22;
    --header-bg: rgba(13,17,23,0.92);
    --accent-bg: rgba(31, 111, 235, 0.22);
    --accent-text: #c9d1d9;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d1117;
  --panel: #161b22;
  --panel-2: #21262d;
  --text: #e6edf3;
  --muted: #9da7b3;
  --border: #30363d;
  --link: #58a6ff;
  --link-hover: #79c0ff;
  --code-bg: #161b22;
  --header-bg: rgba(13,17,23,0.92);
  --accent-bg: rgba(31, 111, 235, 0.22);
  --accent-text: #c9d1d9;
}

:root[data-theme="light"] {
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hover); text-decoration: underline; }
code, pre, kbd, samp {
  font-family: ui-monospace, SFMono-Regular, SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
}
code {
  background: var(--code-bg);
  padding: 0.12rem 0.32rem;
  border-radius: 0.35rem;
  font-size: 0.92em;
}
pre {
  background: var(--code-bg);
  padding: 1rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
}
pre code { background: transparent; padding: 0; }
blockquote {
  margin: 1rem 0;
  padding: 0.1rem 1rem;
  border-left: 0.25rem solid var(--border);
  color: var(--muted);
  background: var(--panel);
}
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  display: block;
  overflow-x: auto;
}
th, td {
  border: 1px solid var(--border);
  padding: 0.55rem 0.75rem;
  vertical-align: top;
}
th { background: var(--panel); }
hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--header-bg);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.85rem 1rem;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
}
.site-title {
  font-weight: 700;
  color: var(--text);
}
.site-title:hover { text-decoration: none; }
.top-nav, .lang-switcher {
  display: flex;
  gap: 0.85rem;
  align-items: center;
  flex-wrap: wrap;
}
.theme-toggle {
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--muted);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  font: inherit;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.theme-toggle:hover {
  background: var(--panel-2);
  color: var(--text);
}
.theme-toggle-label {
  display: inline-flex;
  gap: 0.35rem;
  align-items: center;
}
.top-nav a, .lang-switcher a, .lang-switcher span {
  color: var(--muted);
  font-size: 0.95rem;
}
.top-nav a.current, .lang-switcher .current {
  color: var(--text);
  font-weight: 600;
}
.site-note {
  width: 100%;
  color: var(--muted);
  font-size: 0.92rem;
}
.page-shell {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
}
.with-sidebar {
  display: grid;
  grid-template-columns: minmax(0, var(--sidebar-width)) minmax(0, 1fr);
  gap: 2rem;
}
.sidebar {
  align-self: start;
  position: sticky;
  top: 4.75rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1rem;
  max-height: calc(100vh - 6rem);
  overflow: auto;
}
.sidebar h2 {
  font-size: 1rem;
  margin: 0 0 0.85rem;
}
.sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar .sidebar-root > li + li { margin-top: 0.6rem; }
.sidebar .sidebar-group {
  margin-top: 0.75rem;
}
.sidebar .sidebar-group-title {
  margin: 0 0 0.35rem;
  padding: 0 0.45rem;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.sidebar .sidebar-sublist {
  padding-left: 0.5rem;
  border-left: 1px solid var(--border);
  margin-left: 0.45rem;
}
.sidebar li + li { margin-top: 0.35rem; }
.sidebar a {
  display: block;
  padding: 0.25rem 0.45rem;
  border-radius: 0.35rem;
  color: var(--muted);
}
.sidebar a:hover {
  background: var(--panel-2);
  text-decoration: none;
  color: var(--text);
}
.sidebar a.current {
  background: var(--accent-bg);
  color: var(--accent-text);
  font-weight: 600;
}
.content {
  min-width: 0;
}
.content-header {
  margin-bottom: 1.5rem;
}
.breadcrumbs {
  font-size: 0.92rem;
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.breadcrumbs a { color: var(--muted); }
.meta-row {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
  flex-wrap: wrap;
}
.content h1, .content h2, .content h3, .content h4 {
  line-height: 1.25;
  scroll-margin-top: 5rem;
}
.content h1 { margin-top: 0; }
.footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.92rem;
}
.landing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}
.card {
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1rem;
  background: var(--panel);
}
.card h2, .card h3 { margin-top: 0; }
.card ul {
  margin: 0.5rem 0 0;
  padding-left: 1.2rem;
}
@media (max-width: 900px) {
  .with-sidebar { grid-template-columns: 1fr; }
  .sidebar {
    position: static;
    max-height: none;
  }
}
@media (max-width: 640px) {
  .site-header-inner { align-items: flex-start; }
  .meta-row { flex-direction: column; }
  .page-shell { padding-inline: 0.8rem; }
}