:root {
  color-scheme: light dark;

  --bg: #ffffff;
  --surface: #ffffff;
  --surface-muted: #f6f8fa;
  --text: #1f2328;
  --text-soft: #59636e;
  --heading: #0f172a;
  --heading-strong: #111827;
  --line: #d0d7de;
  --accent: #0969da;
  --accent-soft: #ddf4ff;
  --code-bg: #f6f8fa;
  --code-line: #d8dee4;
  --nav-bg: #f6f8fa;
  --nav-link: #344054;
  --nav-link-hover: #0969da;
  --shadow: 0 8px 24px rgba(16, 24, 40, 0.06);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --surface: #111827;
    --surface-muted: #161b22;
    --text: #e6edf3;
    --text-soft: #9da7b3;
    --heading: #f0f6fc;
    --heading-strong: #ffffff;
    --line: #30363d;
    --accent: #58a6ff;
    --accent-soft: #1f2a37;
    --code-bg: #161b22;
    --code-line: #30363d;
    --nav-bg: #111827;
    --nav-link: #c9d1d9;
    --nav-link-hover: #58a6ff;
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

html {
  background: var(--bg);
}

body {
  font-family: Inter, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.layout {
  display: grid;
  grid-template-columns: minmax(240px, 300px) minmax(0, 1fr);
  min-height: 100vh;
  background: var(--bg);
}

nav {
  background: var(--nav-bg);
  border-right: 1px solid var(--line);
  padding: 24px 18px 28px;
  overflow-y: auto;
  position: sticky;
  top: 0;
  height: 100vh;
  align-self: start;
}

main {
  max-width: 1100px;
  padding: 38px 54px;
  background: var(--bg);
}

h1, h2, h3, h4, h5 {
  color: var(--heading);
  line-height: 1.25;
}

h1 {
  margin: 0 0 6px;
  font-size: clamp(1.8rem, 2.7vw, 2.3rem);
  letter-spacing: -0.02em;
}

h2 {
  margin-top: 42px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 8px;
  font-size: 1.5rem;
}

h3 {
  margin-top: 30px;
  font-size: 1.25rem;
}

h4 {
  margin-top: 22px;
  margin-bottom: 12px;
  font-size: 1.1rem;
}

h5 {
  margin-top: 16px;
  margin-bottom: 8px;
  font-size: 1rem;
  font-weight: 650;
  color: var(--heading-strong);
}

p, ul, ol {
  margin-top: 0.4rem;
  margin-bottom: 0.7rem;
}

ul, ol {
  padding-left: 1.25rem;
}

code {
  background: var(--code-bg);
  border: 1px solid var(--code-line);
  border-radius: 6px;
  padding: 0.05rem 0.35rem;
  font-size: 0.92em;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--code-line);
  border-radius: 10px;
  padding: 14px 16px;
  overflow-x: auto;
}

pre code {
  background: transparent;
  border: none;
  padding: 0;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.meta {
  color: var(--text-soft);
  font-size: 0.88rem;
  margin-bottom: 8px;
}

details {
  margin-bottom: 8px;
  border-radius: 8px;
}

summary {
  cursor: pointer;
  font-weight: 650;
  color: var(--heading);
}

.nav-group {
  margin-left: 10px;
}

.nav-page {
  display: block;
  margin: 5px 0 5px 10px;
  padding: 6px 10px;
  border-radius: 8px;
  color: var(--nav-link);
  transition: background-color 0.15s ease, color 0.15s ease;
}

.nav-page:hover {
  background: var(--accent-soft);
  color: var(--nav-link-hover);
  text-decoration: none;
}

main > h4[id] {
  scroll-margin-top: 18px;
}

main h4[id] {
  margin-top: 28px;
  padding: 0;
  background: transparent;
  border: none;
  box-shadow: none;
  color: var(--heading-strong);
  letter-spacing: -0.01em;
}

.page-anchor {
  scroll-margin-top: 18px;
}

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

  nav {
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--line);
  }

  main {
    padding: 24px 18px 42px;
  }
}