/* ============================================================================
   Building Agentic Systems — Apple-like reading chrome
   mdBook :root font-size is 62.5% → 1rem = 10px
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Hanken+Grotesk:ital,wght@0,400;0,500;0,600;0,700;0,800;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bas-body: "Hanken Grotesk", -apple-system, system-ui, "Segoe UI", Roboto, sans-serif;
  --bas-sans: var(--bas-body);
  --bas-mono: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;

  /* Apple-adjacent palette */
  --bas-bg: #ffffff;
  --bas-bg-subtle: #f5f5f7;
  --bas-fg: #1d1d1f;              /* near-black — reads as black, softer than #000 */
  --bas-fg-secondary: #6e6e73;
  --bas-fg-tertiary: #86868b;
  --bas-link: #0066cc;
  --bas-link-hover: #0077ed;
  /* Separators stay whisper-quiet — structure comes from space, not lines */
  --bas-rule: rgba(0, 0, 0, 0.06);
  --bas-rule-soft: rgba(0, 0, 0, 0.04);
  --bas-radius: 14px;
  --bas-radius-sm: 10px;

  /* Keep older var names working */
  --bas-accent: var(--bas-link);
}

.light,
html:not(.js),
:root {
  --bg: var(--bas-bg);
  --fg: var(--bas-fg);
  --sidebar-bg: var(--bas-bg-subtle);
  --sidebar-fg: var(--bas-fg);
  --sidebar-active: var(--bas-fg);
  --sidebar-non-existant: var(--bas-fg-tertiary);
  --sidebar-spacer: transparent;
  --sidebar-header-border-color: transparent;
  --table-border-color: transparent;
  --quote-border: transparent;
  --links: var(--bas-link);
  --icons: var(--bas-fg-tertiary);
  --icons-hover: var(--bas-fg);
  --theme-hover: var(--bas-bg-subtle);
  --quote-bg: var(--bas-bg-subtle);
  --table-header-bg: transparent;
  --searchbar-bg: var(--bas-bg);
  --searchbar-border: transparent;
  --searchresults-header-fg: var(--bas-fg-secondary);
  --searchresults-border-color: transparent;
}

html, body {
  font-family: var(--bas-body);
  background-color: var(--bas-bg);
  color: var(--bas-fg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html,
body,
.page,
.page-wrapper,
.content,
#content,
.content main,
#menu-bar,
#mdbook-menu-bar,
#menu-bar-hover-placeholder,
#mdbook-menu-bar-hover-placeholder {
  background-color: var(--bas-bg) !important;
  background: var(--bas-bg) !important;
  color: var(--bas-fg) !important;
}

/* Kill the sticky header hairline (mdBook uses #mdbook-menu-bar + .bordered). */
#menu-bar,
#mdbook-menu-bar,
#mdbook-menu-bar.bordered,
#mdbook-menu-bar.sticky {
  border: none !important;
  border-block-end: none !important;
  border-bottom: none !important;
  box-shadow: none !important;
  backdrop-filter: saturate(180%) blur(20px);
  background: rgba(255, 255, 255, 0.78) !important;
}

/* Kill sidebar part separators from SUMMARY --- / .spacer */
.spacer,
.chapter .spacer,
li.spacer {
  display: none !important;
  height: 0 !important;
  margin: 0 !important;
  padding: 0 !important;
  background: transparent !important;
  border: none !important;
}

.on-this-page {
  border-inline-start: none !important;
  border-left: none !important;
  margin-left: 12px;
  padding-left: 0;
}

/* ── Reading column ─────────────────────────────────────────────────────── */

.content main {
  font-family: var(--bas-body);
  font-size: 1.8rem;              /* 18px */
  font-weight: 400;
  line-height: 1.72;
  letter-spacing: -0.015em;
  max-width: 72rem;
  margin: 0 auto;
  color: var(--bas-fg);
  text-rendering: optimizeLegibility;
}

.content main p {
  margin: 0 0 1.1em 0;
  color: var(--bas-fg);
}

.content main li {
  color: var(--bas-fg);
}

.content main hr {
  border: none;
  height: 0;
  margin: 2.8em 0;
  background: none;
}

/* ── Headings — large, light tracking, no loud chrome ───────────────────── */

.content main h1,
.content main h2,
.content main h3,
.content main h4 {
  font-family: var(--bas-sans);
  color: var(--bas-fg);
  border: none;
  padding: 0;
}

.content main h1 {
  font-size: 3.6rem;              /* 36px */
  font-weight: 500;               /* light display weight — not heavy bold */
  letter-spacing: -0.028em;
  line-height: 1.12;
  margin: 0.15em 0 0.75em;
  padding-bottom: 0;
  border-bottom: none;
}

.content main h2 {
  font-size: 2.2rem;              /* 22px */
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin: 2.4em 0 0.65em;
}

.content main h2::before {
  content: none;                  /* drop the § accent mark */
}

.content main h3 {
  font-size: 1.8rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  margin: 2em 0 0.5em;
  color: var(--bas-fg);
}

/* ── Links — Apple blue, no heavy underline bar ─────────────────────────── */

.content main a,
.content main a:visited {
  color: var(--bas-link);
  text-decoration: none;
  border-bottom: none;
  transition: color 0.15s ease;
}

.content main a:hover {
  color: var(--bas-link-hover);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  border-bottom: none;
}

/* ── Code ───────────────────────────────────────────────────────────────── */

.content main code {
  font-family: var(--bas-mono);
  font-size: 0.84em;
  color: var(--bas-fg);
  background: var(--bas-bg-subtle);
  padding: 0.12em 0.4em;
  border-radius: 6px;
  border: none;
}

.content main pre {
  background: var(--bas-bg-subtle) !important;
  border: none;
  border-radius: var(--bas-radius);
  line-height: 1.55;
  margin: 1.8em 0;
  padding: 1.5rem 1.7rem;
  box-shadow: none;
}

.content main pre > code {
  font-size: 1.45rem;             /* 14.5px */
  background: transparent;
  padding: 0;
  color: var(--bas-fg);
}

/* ── Tables ─────────────────────────────────────────────────────────────── */

.content main table {
  font-family: var(--bas-sans);
  font-size: 1.55rem;
  line-height: 1.5;
  margin: 2em auto;
  border-collapse: separate;
  border-spacing: 0;
  width: 100%;
  border: none;
  background: var(--bas-bg-subtle);
  border-radius: var(--bas-radius);
  overflow: hidden;
}

.content main table th {
  font-weight: 600;
  text-align: left;
  color: var(--bas-fg-secondary);
  font-size: 1.25rem;
  letter-spacing: 0.01em;
  text-transform: none;
  border: none;
  padding: 1em 1.1em 0.65em;
  background: transparent;
}

.content main table td {
  border: none !important;
  padding: 0.85em 1.1em;
  vertical-align: top;
  color: var(--bas-fg);
}

.content main table th,
.content main table td {
  border: none !important;
}

.content main table tbody tr:nth-child(2n) {
  background: transparent;
}

/* ── Blockquotes ────────────────────────────────────────────────────────── */

.content main blockquote {
  margin: 1.8em 0;
  padding: 1.2em 1.5em;
  border: none;
  background: var(--bas-bg-subtle);
  border-radius: var(--bas-radius);
  font-style: normal;
  font-weight: 400;
  color: var(--bas-fg-secondary);
}

.content main blockquote p {
  color: var(--bas-fg-secondary);
}

/* ── Figures & videos ───────────────────────────────────────────────────── */

.content main video,
.content main .figure video,
.content main .figure img {
  display: block;
  max-width: min(100%, 760px);
  margin: 2rem auto;
  border-radius: var(--bas-radius);
  border: none;
  background: #000000;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

.content main .figure figcaption {
  margin-top: 0.7rem;
  font-family: var(--bas-sans);
  font-size: 1.35rem;
  text-align: center;
  color: var(--bas-fg-tertiary);
}

.content main .mermaid {
  margin: 1.8em auto;
  text-align: center;
}

/* ── Sidebar — quiet, product-nav feel ──────────────────────────────────── */

.sidebar {
  font-family: var(--bas-sans);
  background-color: var(--bas-bg-subtle) !important;
  color: var(--bas-fg);
  border: none !important;
  border-right: none !important;
  box-shadow: none !important;
}

.sidebar .part-title,
.chapter li.part-title,
.chapter li.header-item {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--bas-fg-tertiary) !important;
  opacity: 1;
  margin-top: 1.75rem;
  margin-bottom: 0.35rem;
  padding-left: 1rem;
  border: none !important;
  background: transparent !important;
}

.sidebar ol li a {
  padding: 0.35rem 1rem;
  line-height: 1.35;
  color: var(--bas-fg-secondary) !important;
  border-radius: 8px;
  margin: 0 0.5rem;
  transition: background 0.12s ease, color 0.12s ease;
}

.sidebar ol li a:hover {
  background: rgba(0, 0, 0, 0.04);
  color: var(--bas-fg) !important;
}

.sidebar ol li.active > a {
  font-weight: 600;
  color: var(--bas-fg) !important;
  background: rgba(0, 0, 0, 0.06);
}

/* Chapter nav at bottom of page */
.nav-chapters {
  color: var(--bas-fg-tertiary) !important;
}
.nav-chapters:hover {
  color: var(--bas-fg) !important;
}