@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,300;0,400;0,500;0,600;1,300;1,400;1,500&family=DM+Sans:wght@300;400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

/* ─── Tokens ─────────────────────────────────────────────── */
:root {
  --bg:           oklch(98.5% 0.005 245);
  --surface:      oklch(96.5% 0.008 245);
  --surface2:     oklch(94%   0.010 245);
  --border:       oklch(88%   0.012 245);
  --border-light: oklch(93%   0.007 245);
  --text:         oklch(15%   0.020 255);
  --text-muted:   oklch(48%   0.018 255);
  --text-faint:   oklch(62%   0.012 255);
  --accent:       oklch(44%   0.140 255);
  --accent-mid:   oklch(56%   0.130 255);
  --accent-light: oklch(88%   0.055 255);
  --accent-xlt:   oklch(96%   0.022 255);
  --amber:        oklch(68%   0.145  68);
  --amber-light:  oklch(95%   0.040  68);
  --code-bg:      oklch(95%   0.010 245);

  --serif:  'Crimson Pro', Georgia, 'Times New Roman', serif;
  --sans:   'DM Sans', system-ui, -apple-system, sans-serif;
  --mono:   'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --r-sm: 3px;
  --r:    6px;
  --r-lg: 10px;

  --shadow-sm: 0 1px 3px oklch(0% 0 0 / .06), 0 1px 2px oklch(0% 0 0 / .04);
  --shadow:    0 2px 8px oklch(0% 0 0 / .08), 0 1px 3px oklch(0% 0 0 / .05);
}

/* ─── Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 18px; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--serif);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  font-weight: 400;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ─── Navigation ─────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 0;
  height: 44px;
  padding: 0 32px;
  background: oklch(99% 0.004 245 / .92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
}
.nav-home {
  font-family: var(--sans);
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 6px;
  padding-right: 20px;
  margin-right: 20px;
  border-right: 1px solid var(--border);
  white-space: nowrap;
  flex-shrink: 0;
}
.nav-home:hover { color: var(--accent); text-decoration: none; }
.nav-home .arrow { font-size: .9em; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
}
.nav-links::-webkit-scrollbar { display: none; }
.nav-link {
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 400;
  letter-spacing: .03em;
  color: var(--text-muted);
  text-decoration: none;
  padding: 4px 10px;
  border-radius: var(--r-sm);
  white-space: nowrap;
  transition: color .15s, background .15s;
}
.nav-link:hover { color: var(--accent); background: var(--accent-xlt); text-decoration: none; }
.nav-link.active { color: var(--accent); background: var(--accent-xlt); }

.nav-spacer { flex: 1; }

.nav-github {
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  border: 1px solid var(--border);
  border-radius: var(--r);
  transition: color .15s, border-color .15s;
}
.nav-github:hover { color: var(--accent); border-color: var(--accent-light); text-decoration: none; }
.nav-github svg { width: 14px; height: 14px; }

/* ─── Page layout ────────────────────────────────────────── */
.page-wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 32px;
}

/* Two-column layout for home page */
.layout-two-col {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 0 56px;
  align-items: start;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 32px;
}

/* Single column for article pages */
.layout-article {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ─── Sidebar / TOC ──────────────────────────────────────── */
.sidebar {
  position: sticky;
  top: 60px;
  padding: 40px 0;
  font-family: var(--sans);
}
.sidebar-brand {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -.01em;
  margin-bottom: 2px;
}
.sidebar-tagline {
  font-size: .72rem;
  color: var(--text-muted);
  line-height: 1.4;
  margin-bottom: 20px;
}
.sidebar-section {
  margin-bottom: 18px;
}
.sidebar-label {
  font-size: .62rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 6px;
  display: block;
}
.sidebar-links { display: flex; flex-direction: column; gap: 1px; }
.sidebar-link {
  font-size: .76rem;
  color: var(--text-muted);
  text-decoration: none;
  padding: 3px 8px;
  border-radius: var(--r-sm);
  transition: color .13s, background .13s;
}
.sidebar-link:hover { color: var(--accent); background: var(--accent-xlt); text-decoration: none; }
.sidebar-divider { height: 1px; background: var(--border-light); margin: 14px 0; }
.sidebar-btn {
  display: block;
  font-size: .72rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  padding: 6px 10px;
  border: 1px solid var(--accent-light);
  border-radius: var(--r);
  margin-bottom: 6px;
  transition: background .13s;
  text-align: center;
}
.sidebar-btn:hover { background: var(--accent-xlt); text-decoration: none; }

/* ─── Typography ─────────────────────────────────────────── */
.content { padding: 48px 0 80px; }

h1, h2, h3, h4 { font-family: var(--serif); font-weight: 500; line-height: 1.25; color: var(--text); }

h1 { font-size: 2.4rem; letter-spacing: -.02em; margin-bottom: .5em; }
h2 { font-size: 1.55rem; letter-spacing: -.01em; margin: 2.4em 0 .6em; padding-bottom: .4em; border-bottom: 1px solid var(--border-light); }
h3 { font-size: 1.15rem; font-weight: 600; margin: 1.8em 0 .5em; }
h4 { font-size: .95rem; font-weight: 600; margin: 1.4em 0 .35em; font-family: var(--sans); letter-spacing: .01em; }

.page-subtitle {
  font-size: 1.35rem;
  font-weight: 300;
  font-style: italic;
  color: var(--text-muted);
  margin-bottom: 1.5em;
  line-height: 1.4;
}

p { margin-bottom: 1em; }
p + p { margin-top: -.1em; }
strong, b { font-weight: 600; }
em, i { font-style: italic; }

/* ─── Code ───────────────────────────────────────────────── */
code {
  font-family: var(--mono);
  font-size: .80em;
  background: var(--code-bg);
  color: var(--accent);
  padding: .15em .4em;
  border-radius: var(--r-sm);
  border: 1px solid var(--border-light);
}
pre {
  font-family: var(--mono);
  font-size: .78rem;
  line-height: 1.6;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 18px 20px;
  overflow-x: auto;
  margin: 1.2em 0;
  color: var(--text);
}
pre code {
  font-size: 1em;
  background: none;
  color: inherit;
  padding: 0;
  border: none;
  border-radius: 0;
}

/* ─── Badges / tags ──────────────────────────────────────── */
.badge-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 1.4em; }
.badge {
  font-family: var(--sans);
  font-size: .65rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 99px;
  border: 1px solid transparent;
}
.badge-default { background: var(--surface2); color: var(--text-muted); border-color: var(--border); }
.badge-accent  { background: var(--accent-xlt); color: var(--accent); border-color: var(--accent-light); }
.badge-amber   { background: var(--amber-light); color: oklch(40% 0.12 68); border-color: oklch(80% 0.09 68); }
.badge-doi     { background: var(--accent-xlt); color: var(--accent); border-color: var(--accent-light); font-size: .62rem; }

.fn-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: .68rem;
  padding: 2px 7px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  color: var(--text-muted);
}

/* ─── Note / callout ─────────────────────────────────────── */
.note {
  background: var(--amber-light);
  border-left: 3px solid var(--amber);
  border-radius: 0 var(--r) var(--r) 0;
  padding: 14px 18px;
  margin: 1.5em 0;
  font-size: .9rem;
}
.note-label { font-weight: 600; }

.note-info {
  background: var(--accent-xlt);
  border-left: 3px solid var(--accent-light);
  border-radius: 0 var(--r) var(--r) 0;
  padding: 14px 18px;
  margin: 1.5em 0;
  font-size: .9rem;
}

/* ─── Tables ─────────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .88rem;
  margin: 1.4em 0;
}
thead th {
  font-family: var(--sans);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-align: left;
  padding: 8px 14px;
  border-bottom: 2px solid var(--border);
  background: var(--surface);
}
tbody td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-light);
  vertical-align: top;
}
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover td { background: var(--accent-xlt); }
td a { font-weight: 500; }

/* ─── Function card ──────────────────────────────────────── */
.fn-section { margin: 2em 0 3em; }
.fn-section h3 {
  font-family: var(--mono);
  font-size: .9rem;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: .3em;
  letter-spacing: .01em;
}
.fn-sig {
  font-family: var(--mono);
  font-size: .82rem;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: 10px 14px;
  margin: .6em 0 1em;
  overflow-x: auto;
}
.fn-meta {
  font-size: .82rem;
  color: var(--text-muted);
  font-style: italic;
  margin-top: .8em;
}
.fn-meta a { font-style: normal; }

/* ─── Example cards ──────────────────────────────────────── */
.example-section-label {
  font-family: var(--sans);
  font-size: .65rem;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: 0 0 10px;
  border-bottom: 1px solid var(--border-light);
  margin: 2.5em 0 1em;
  display: flex;
  align-items: center;
  gap: 10px;
}
.example-section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-light);
}

.example-card {
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 22px 24px;
  margin-bottom: 12px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color .15s, box-shadow .15s, background .15s;
  background: white;
}
.example-card:hover {
  border-color: var(--accent-light);
  box-shadow: var(--shadow);
  background: var(--accent-xlt);
  text-decoration: none;
  color: inherit;
}
.example-card-meta {
  font-family: var(--sans);
  font-size: .63rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 5px;
}
.example-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 .5em;
  color: var(--text);
}
.example-card p {
  font-size: .88rem;
  color: var(--text-muted);
  margin: 0 0 .8em;
  line-height: 1.5;
}
.example-card-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-top: .6em; }
.example-card-tags .fn-tag { color: var(--accent); }

.example-card-coming {
  opacity: .55;
  pointer-events: none;
}
.coming-label {
  font-family: var(--sans);
  font-size: .65rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-faint);
  border: 1px dashed var(--border);
  border-radius: 99px;
  padding: 2px 8px;
  margin-left: 8px;
}

/* ─── Article page specific ──────────────────────────────── */
.article-hero { padding: 48px 0 32px; }
.article-meta {
  font-family: var(--sans);
  font-size: .75rem;
  color: var(--text-faint);
  margin-top: 1em;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}
.article-meta a { color: var(--text-faint); }
.article-meta a:hover { color: var(--accent); }

.article-divider { height: 1px; background: var(--border); margin: 28px 0; }

.section-number {
  font-family: var(--sans);
  font-size: .75rem;
  font-weight: 600;
  color: var(--text-faint);
  margin-right: 8px;
}

/* ─── Section anchor nav (within a page) ─────────────────── */
.page-toc {
  font-family: var(--sans);
  font-size: .72rem;
  color: var(--text-faint);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  padding: 10px 0;
  margin: 0 0 2.5em;
  display: flex;
  flex-wrap: wrap;
  gap: 2px 4px;
  align-items: center;
}
.page-toc-label { font-weight: 600; color: var(--text-muted); margin-right: 6px; }
.page-toc a {
  color: var(--text-faint);
  padding: 2px 6px;
  border-radius: var(--r-sm);
  transition: color .12s, background .12s;
}
.page-toc a:hover { color: var(--accent); background: var(--accent-xlt); text-decoration: none; }

/* ─── Benchmarks & figures ───────────────────────────────── */
.figure-wrap {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  overflow: hidden;
  margin: 1.5em 0;
}
.figure-placeholder {
  width: 100%;
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: repeating-linear-gradient(
    45deg,
    var(--surface) 0px,
    var(--surface) 10px,
    var(--border-light) 10px,
    var(--border-light) 11px
  );
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--text-faint);
  text-align: center;
  padding: 20px;
}
.figure-caption {
  padding: 10px 16px;
  font-size: .82rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
  font-style: italic;
  line-height: 1.5;
}

/* ─── Code tabs ──────────────────────────────────────────── */
.code-tabs { margin: 1.5em 0; }
.code-tab-bar {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0;
}
.code-tab-btn {
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 500;
  padding: 7px 14px;
  border: none;
  background: none;
  color: var(--text-faint);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color .13s, border-color .13s;
}
.code-tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }
.code-tab-btn:hover:not(.active) { color: var(--text-muted); }
.code-tab-panel { display: none; }
.code-tab-panel.active { display: block; }
.code-tab-panel pre { border-radius: 0 var(--r-lg) var(--r-lg); margin-top: 0; border-top: none; }

/* ─── Reproduce steps ────────────────────────────────────── */
.steps { counter-reset: step; margin: 1.5em 0; }
.step {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 0 16px;
  margin-bottom: 1.5em;
  align-items: start;
}
.step-num {
  counter-increment: step;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--sans);
  font-size: .7rem;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 3px;
}
.step-content h4 { margin-top: 0; }

/* ─── Footer ─────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border-light);
  padding: 28px 0 36px;
  margin-top: 60px;
  font-family: var(--sans);
  font-size: .73rem;
  color: var(--text-faint);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 4px 14px; }
.footer-links a { color: var(--text-faint); }
.footer-links a:hover { color: var(--accent); }

/* ─── Responsive ─────────────────────────────────────────── */
@media (max-width: 768px) {
  html { font-size: 16px; }
  .site-nav { padding: 0 16px; }
  .layout-two-col { grid-template-columns: 1fr; }
  .layout-article { padding: 0 20px; }
  .sidebar { position: static; }
  .page-wrap { padding: 0 16px; }
  .layout-two-col { padding: 0 16px; }

  /* Touch-friendly hit areas */
  .lang-toggle button { padding: 6px 12px; min-height: 34px; }
  .nav-github { min-height: 34px; padding: 6px 10px; }
  .nav-link { padding: 6px 10px; min-height: 34px; }

  /* Compact the logo gap — border is already removed inline on the home link */
  .nav-home { padding-right: 10px; margin-right: 10px; }
}