:root {
  --ink: #0f172a;
  --ink-soft: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --accent: #4f46e5;
  --accent-strong: #4338ca;
  --accent-soft: #eef2ff;
  --gradient: radial-gradient(1200px 600px at 85% -10%, rgba(99, 102, 241, 0.18), transparent 60%),
              radial-gradient(900px 500px at 0% 10%, rgba(14, 165, 233, 0.12), transparent 55%),
              linear-gradient(180deg, #0b1020 0%, #111936 60%, #1b2350 100%);
  --radius: 14px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 1px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

code {
  font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.92em;
  background: var(--accent-soft);
  color: var(--accent-strong);
  padding: 0.12em 0.4em;
  border-radius: 6px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(1.3) blur(10px);
  background: rgba(11, 16, 32, 0.72);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.site-header__inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 600;
  letter-spacing: 0.2px;
}
.site-brand:hover { text-decoration: none; color: #fff; }
.site-brand__mark {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, #6366f1, #0ea5e9);
  color: #fff;
  font-size: 16px;
}
.site-nav {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}
.site-nav a {
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.95rem;
  font-weight: 500;
}
.site-nav a:hover { color: #fff; text-decoration: none; }

/* ---------- Hero ---------- */
.hero {
  background: var(--gradient);
  color: #e6ecff;
  padding: 84px 24px 96px;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 50% 0%, black 30%, transparent 70%);
  pointer-events: none;
}
.hero__inner {
  position: relative;
  max-width: 1120px;
  margin: 0 auto;
}
.hero__eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #a5b4fc;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(165, 180, 252, 0.3);
  padding: 6px 12px;
  border-radius: 999px;
  margin-bottom: 22px;
}
.hero__title {
  margin: 0 0 14px;
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  line-height: 1.05;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.02em;
  background: linear-gradient(90deg, #ffffff 0%, #c7d2fe 60%, #93c5fd 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__subtitle {
  margin: 0 0 20px;
  color: #c7d2fe;
  font-size: 1.15rem;
  font-weight: 500;
}
.hero__lede {
  max-width: 720px;
  color: rgba(230, 236, 255, 0.85);
  font-size: 1.05rem;
  margin: 0 0 30px;
}
.hero__lede strong { color: #fff; font-weight: 600; }

.hero__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 40px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 10px;
  font-weight: 500;
  font-size: 0.95rem;
  transition: transform 0.12s ease, background 0.2s ease, border-color 0.2s ease;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn--primary {
  background: #fff;
  color: var(--ink);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
}
.btn--primary:hover { background: #f1f5ff; color: var(--accent-strong); }
.btn--ghost {
  background: rgba(255, 255, 255, 0.06);
  color: #e6ecff;
  border-color: rgba(255, 255, 255, 0.18);
}
.btn--ghost:hover { background: rgba(255, 255, 255, 0.12); color: #fff; }

.hero__meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  max-width: 720px;
  margin: 0;
  padding: 18px 22px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
}
.hero__meta div { display: flex; flex-direction: column; gap: 4px; }
.hero__meta dt {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #a5b4fc;
}
.hero__meta dd {
  margin: 0;
  color: #fff;
  font-weight: 500;
  font-size: 0.95rem;
}

/* ---------- Page body ---------- */
.page { padding: 64px 24px 96px; }
.page__inner { max-width: 880px; margin: 0 auto; }

.markdown-body h1 { display: none; } /* hide duplicate title from index.md */
.markdown-body h2 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 56px 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
}
.markdown-body h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 32px 0 10px;
  color: var(--ink);
}
.markdown-body h3::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 2px;
  margin-right: 10px;
  transform: translateY(-3px);
}
.markdown-body p, .markdown-body li { color: var(--ink-soft); }
.markdown-body hr { display: none; }
.markdown-body ul { padding-left: 1.2rem; }
.markdown-body ul li { margin: 6px 0; }
.markdown-body ul li::marker { color: var(--accent); }

.markdown-body blockquote {
  margin: 20px 0;
  padding: 14px 18px;
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  color: var(--ink-soft);
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  margin: 16px 0;
}
.markdown-body table th {
  text-align: left;
  background: var(--bg-soft);
  color: var(--ink);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
}
.markdown-body table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
}
.markdown-body table tr:last-child td { border-bottom: none; }

/* anchor-js anchors */
.markdown-body .anchorjs-link {
  color: var(--muted);
  opacity: 0;
  transition: opacity 0.15s ease;
}
.markdown-body h2:hover .anchorjs-link,
.markdown-body h3:hover .anchorjs-link { opacity: 1; }

.slides-embed {
  display: block;
  width: 100%;
  height: min(80vh, 720px);
  margin: 20px 0 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-soft);
  box-shadow: var(--shadow-sm);
}

/* ---------- Footer ---------- */
.site-footer {
  background: #0b1020;
  color: rgba(230, 236, 255, 0.75);
  padding: 48px 24px 28px;
  margin-top: 40px;
}
.site-footer__inner {
  max-width: 1120px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
}
.site-footer h4 {
  margin: 0 0 8px;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #a5b4fc;
  font-weight: 600;
}
.site-footer p { margin: 0; font-size: 0.95rem; line-height: 1.5; }
.site-footer code {
  background: rgba(255, 255, 255, 0.06);
  color: #c7d2fe;
  border: 1px solid rgba(255, 255, 255, 0.08);
}
.site-footer a { color: #a5b4fc; }
.site-footer__rule {
  max-width: 1120px;
  margin: 28px auto 0;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.85rem;
  color: rgba(230, 236, 255, 0.55);
}

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .hero { padding: 60px 20px 72px; }
  .hero__meta { grid-template-columns: 1fr; }
  .site-nav { display: none; }
  .page { padding: 44px 20px 72px; }
}