*, *::before, *::after {
  box-sizing: border-box;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1e1b2e;
  --color-muted: #6b7280;
  --color-primary: #2f215b;
  --color-primary-light: #675797;
  --color-accent: #008cff;
  --color-border: #e5e7eb;
  --color-code-bg: #f3f4f6;
  --color-nav-bg: #2f215b;
  --font-sans: system-ui, -apple-system, sans-serif;
  --font-mono: "Fira Code", "Cascadia Code", ui-monospace, monospace;
  --max-width: 1100px;
  --sidebar-width: 220px;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
}

/* ── Navigation ── */

.site-nav {
  background: var(--color-nav-bg);
  color: #fff;
  padding: 0 1.5rem;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-brand {
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
  font-family: var(--font-mono);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s;
}

.nav-links a:hover,
.nav-links a.active {
  color: #fff;
}

/* ── Page Layout ── */

.page-layout {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  display: flex;
  gap: 3rem;
  min-height: calc(100vh - 56px - 60px);
}

/* ── Sidebar ── */

.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  position: sticky;
  top: 2rem;
  align-self: flex-start;
}

.sidebar h3 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-muted);
  margin: 0 0 0.75rem;
}

.sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar li {
  margin-bottom: 0.25rem;
}

.sidebar a {
  display: block;
  padding: 0.35rem 0.75rem;
  color: var(--color-text);
  text-decoration: none;
  font-size: 0.9rem;
  border-radius: 6px;
  transition: background 0.15s;
}

.sidebar a:hover {
  background: var(--color-code-bg);
}

.sidebar a.active {
  background: var(--color-primary);
  color: #fff;
}

/* ── Content ── */

.content {
  flex: 1;
  min-width: 0;
}

.content h1 {
  font-size: 2rem;
  color: var(--color-primary);
  margin: 0 0 1rem;
  line-height: 1.2;
}

.content h2 {
  font-size: 1.4rem;
  color: var(--color-primary);
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--color-border);
}

.content h3 {
  font-size: 1.1rem;
  margin: 1.75rem 0 0.5rem;
}

.content a {
  color: var(--color-accent);
}

.content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

.content pre {
  background: #1e1b2e;
  color: #e2e8f0;
  padding: 1.25rem 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.6;
}

.content pre code {
  background: none;
  padding: 0;
  color: inherit;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.9rem;
}

.content th,
.content td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.content th {
  font-weight: 600;
  color: var(--color-primary);
}

.content blockquote {
  margin: 1rem 0;
  padding: 0.75rem 1.25rem;
  border-left: 3px solid var(--color-accent);
  background: var(--color-code-bg);
  border-radius: 0 6px 6px 0;
}

.content blockquote p {
  margin: 0;
}

/* ── Footer ── */

.site-footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--color-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--color-border);
}

/* ── Landing page ── */

.hero {
  text-align: center;
  padding: 4rem 1rem 3rem;
}

.hero h1 {
  font-size: 2.5rem;
  color: var(--color-primary);
  margin: 0 0 0.75rem;
}

.hero p {
  font-size: 1.15rem;
  color: var(--color-muted);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-links a {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: opacity 0.15s;
}

.hero-links a:hover {
  opacity: 0.88;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-secondary {
  background: var(--color-code-bg);
  color: var(--color-primary);
}

.quick-install {
  max-width: 600px;
  margin: 0 auto 3rem;
}

.quick-install pre {
  background: #1e1b2e;
  color: #e2e8f0;
  padding: 1rem 1.25rem;
  border-radius: 8px;
  font-size: 0.9rem;
  text-align: left;
}

/* ── Playground ── */

.playground-layout {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 2rem;
  align-items: start;
}

@media (max-width: 768px) {
  .page-layout {
    flex-direction: column;
  }

  .sidebar {
    position: static;
    width: 100%;
  }

  .playground-layout {
    grid-template-columns: 1fr;
  }
}