/* ── Reset & base ─────────────────────────────────────────────────────────── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  background: #0f172a;
  color: #cbd5e1;
  line-height: 1.7;
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ─────────────────────────────────────────────────────────────── */
.sidebar {
  position: fixed;
  top: 0; left: 0;
  width: 260px;
  height: 100vh;
  background: #1e293b;
  border-right: 1px solid #334155;
  overflow-y: auto;
  padding: 1.5rem 0;
  z-index: 100;
}
.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #f1f5f9;
  padding: 0 1.25rem 1rem;
  border-bottom: 1px solid #334155;
  margin-bottom: 0.75rem;
}
.sidebar-title span {
  color: #60a5fa;
}
.sidebar nav a {
  display: block;
  padding: 0.45rem 1.25rem;
  color: #94a3b8;
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.15s, color 0.15s;
}
.sidebar nav a:hover { background: #334155; color: #e2e8f0; }
.sidebar nav a.active { background: #334155; color: #60a5fa; border-left: 3px solid #60a5fa; }
.sidebar nav .section-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #475569;
  padding: 1rem 1.25rem 0.3rem;
}
.sidebar nav a.toc-link {
  padding-left: 2.25rem;
  font-size: 0.82rem;
  color: #64748b;
}
.sidebar nav a.toc-link:hover { color: #94a3b8; }

/* ── Main content ────────────────────────────────────────────────────────── */
.content {
  margin-left: 260px;
  flex: 1;
  max-width: 900px;
  padding: 2.5rem 3rem 4rem;
}

/* ── Typography ──────────────────────────────────────────────────────────── */
h1 {
  font-size: 2rem;
  font-weight: 700;
  color: #f1f5f9;
  margin-bottom: 0.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid #334155;
}
h1 + p.subtitle {
  color: #64748b;
  font-size: 0.95rem;
  margin-bottom: 2rem;
}
h2 {
  font-size: 1.4rem;
  font-weight: 600;
  color: #e2e8f0;
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid #1e293b;
}
h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #e2e8f0;
  margin: 1.5rem 0 0.5rem;
}
h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #94a3b8;
  margin: 1.25rem 0 0.4rem;
}
p { margin-bottom: 0.75rem; }
a { color: #60a5fa; text-decoration: none; }
a:hover { text-decoration: underline; }
strong { color: #e2e8f0; }

ul, ol { margin: 0.5rem 0 1rem 1.5rem; }
li { margin-bottom: 0.3rem; }

/* ── Tables ──────────────────────────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.88rem;
}
th {
  text-align: left;
  background: #1e293b;
  color: #94a3b8;
  font-weight: 600;
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid #334155;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid #1e293b;
}
tr:hover td { background: rgba(30,41,59,0.5); }

/* ── Code ────────────────────────────────────────────────────────────────── */
code {
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
  font-size: 0.85em;
  background: #1e293b;
  color: #e2e8f0;
  padding: 0.15em 0.4em;
  border-radius: 4px;
}
pre {
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 8px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  margin: 0.75rem 0 1.25rem;
  font-size: 0.85rem;
  line-height: 1.6;
}
pre code {
  background: none;
  padding: 0;
  border-radius: 0;
}

/* ── Mermaid diagrams ────────────────────────────────────────────────────── */
.diagram-container {
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1rem 0 1.5rem;
  overflow-x: auto;
  text-align: center;
}
.diagram-container .mermaid svg {
  max-width: 100%;
  height: auto;
}

/* ── ASCII art / layout diagrams ─────────────────────────────────────────── */
pre.layout {
  font-size: 0.8rem;
  line-height: 1.5;
  color: #94a3b8;
}

/* ── Callout boxes ───────────────────────────────────────────────────────── */
.callout {
  border-left: 3px solid #60a5fa;
  background: rgba(96,165,250,0.08);
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  border-radius: 0 6px 6px 0;
  font-size: 0.9rem;
}
.callout.warning {
  border-left-color: #f59e0b;
  background: rgba(245,158,11,0.08);
}

/* ── Screenshots ─────────────────────────────────────────────────────────── */
.screenshot {
  margin: 1.25rem 0 1.5rem;
  text-align: center;
}
.screenshot img {
  max-width: 100%;
  border-radius: 8px;
  border: 1px solid #334155;
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
}
.screenshot .caption {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.82rem;
  color: #64748b;
  font-style: italic;
}

/* ── Step boxes (numbered how-to steps) ──────────────────────────────────── */
.step-box {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  background: rgba(30,41,59,0.5);
  border: 1px solid #334155;
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin: 0.75rem 0;
}
.step-box .step-num {
  flex-shrink: 0;
  width: 2rem;
  height: 2rem;
  background: #4F5B93;
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
}
.step-box .step-text {
  flex: 1;
}
.step-box .step-text strong {
  display: block;
  margin-bottom: 0.2rem;
}

/* ── Tip callout (green) ─────────────────────────────────────────────────── */
.callout.tip {
  border-left-color: #2d8a4e;
  background: rgba(45,138,78,0.08);
}

/* ── Responsive ──────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .sidebar { display: none; }
  .content { margin-left: 0; padding: 1.5rem; }
}

/* ── Light mode (follows OS / browser preference) ───────────────────────── */
@media (prefers-color-scheme: light) {
  body { background: #f8fafc; color: #334155; }
  .sidebar { background: #f1f5f9; border-right-color: #e2e8f0; }
  .sidebar-title { color: #0f172a; }
  .sidebar-title span { color: #2563eb; }
  .sidebar nav a { color: #475569; }
  .sidebar nav a:hover { background: #e2e8f0; color: #1e293b; }
  .sidebar nav a.active { background: #e2e8f0; color: #2563eb; border-left-color: #2563eb; }
  .sidebar nav .section-label { color: #94a3b8; }
  .sidebar nav a.toc-link { color: #64748b; }
  .sidebar nav a.toc-link:hover { color: #475569; }
  h1 { color: #0f172a; border-bottom-color: #e2e8f0; }
  h2 { color: #1e293b; border-bottom-color: #e2e8f0; }
  h3 { color: #1e293b; }
  h4 { color: #475569; }
  a { color: #2563eb; }
  strong { color: #1e293b; }
  th { background: #f1f5f9; color: #475569; border-bottom-color: #e2e8f0; }
  td { border-bottom-color: #f1f5f9; }
  tr:hover td { background: rgba(241,245,249,0.7); }
  code { background: #f1f5f9; color: #1e293b; }
  pre { background: #f1f5f9; border-color: #e2e8f0; }
  .diagram-container { background: #f1f5f9; border-color: #e2e8f0; }
  pre.layout { color: #475569; }
  .callout { border-left-color: #2563eb; background: rgba(37,99,235,0.06); }
  .callout.warning { border-left-color: #d97706; background: rgba(217,119,6,0.06); }
  .screenshot img { border-color: #e2e8f0; box-shadow: 0 4px 24px rgba(0,0,0,0.1); }
  .step-box { background: rgba(241,245,249,0.7); border-color: #e2e8f0; }
  .callout.tip { border-left-color: #16a34a; background: rgba(22,163,74,0.06); }
}