:root {
  --bg: #161616;
  --bg-raised: #1d1d1d;
  --bg-hover: #242424;
  --line: #2a2a2a;
  --line-strong: #363636;
  --fg: #e7e7e7;
  --fg-muted: #9a9a9a;
  --fg-faint: #8a8a8a;
  --accent: #a48cff;
  --accent-strong: #b7a3ff;
  --accent-dim: rgba(164, 140, 255, 0.14);
  --ok: #3fc3a8;
  --radius: 10px;
  --radius-sm: 7px;
  --sans: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --measure: 40rem;
  --wide: 66rem;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a:hover { color: var(--accent-strong); text-decoration: underline; text-underline-offset: 0.15em; }

p a, li a, .lede a, .btn-note a, .foot span a {
  text-decoration: underline;
  text-decoration-color: rgba(164, 140, 255, 0.45);
  text-underline-offset: 0.15em;
}

p a:hover, li a:hover { text-decoration-color: var(--accent-strong); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

h1, h2, h3 {
  margin: 0;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.2;
  color: var(--fg);
}

h1 { font-size: clamp(2.1rem, 5vw, 3.2rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.4rem, 3vw, 1.75rem); }
h3 { font-size: 1.05rem; }

p { margin: 0; }

code, pre, kbd {
  font-family: var(--mono);
  font-size: 0.9em;
}

code {
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 0.1em 0.4em;
  color: var(--fg);
}

pre {
  margin: 0;
  padding: 0.95rem 1.1rem;
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  line-height: 1.55;
  color: var(--fg);
}

pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: 0.86rem;
}

kbd {
  background: var(--bg-raised);
  border: 1px solid var(--line-strong);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 0.05em 0.45em;
  font-size: 0.82em;
}

.wrap {
  width: min(100% - 2.5rem, var(--wide));
  margin-inline: auto;
}

.measure { max-width: var(--measure); }

/* Top bar */

.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(22, 22, 22, 0.86);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}

.top .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 3.25rem;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--fg);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.brand:hover { text-decoration: none; color: var(--fg); }

.brand svg { width: 1.15rem; height: 1.15rem; color: var(--accent); }

.nav {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.nav a {
  color: var(--fg-muted);
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
  font-size: 0.93rem;
}

.nav a:hover { color: var(--fg); background: var(--bg-hover); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--fg); }

.nav .gh {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.nav .gh svg { width: 1rem; height: 1rem; }

@media (max-width: 40rem) {
  .nav a { padding: 0.4rem 0.5rem; font-size: 0.88rem; }
  .nav .gh span { display: none; }
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 2.6rem;
  padding: 0 1.15rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line-strong);
  background: var(--bg-raised);
  color: var(--fg);
  font-weight: 500;
  font-size: 0.95rem;
  white-space: nowrap;
  transition: background 120ms ease, border-color 120ms ease, transform 120ms ease;
}

.btn:hover { background: var(--bg-hover); border-color: #444; text-decoration: none; color: var(--fg); }
.btn:active { transform: translateY(1px); }

.btn svg { width: 1.05rem; height: 1.05rem; flex: none; }

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #15112b;
}

.btn-primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); color: #15112b; }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  align-items: center;
}

.btn-note {
  font-size: 0.82rem;
  color: var(--fg-faint);
}

/* Hero */

.hero {
  padding: clamp(3.5rem, 9vw, 6.5rem) 0 clamp(2.5rem, 6vw, 4rem);
  text-align: center;
}

.hero .lede {
  margin: 1.25rem auto 0;
  max-width: 34rem;
  color: var(--fg-muted);
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  line-height: 1.55;
}

.hero .btn-row {
  justify-content: center;
  margin-top: 2rem;
}

.hero .btn-note { margin-top: 0.9rem; }

.shot {
  margin: clamp(2rem, 5vw, 3.5rem) auto 0;
  max-width: 62rem;
  border-radius: var(--radius);
  border: 1px solid var(--line-strong);
  background: var(--bg-raised);
  overflow: hidden;
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.4),
    0 30px 80px -30px rgba(164, 140, 255, 0.22),
    0 20px 50px -20px rgba(0, 0, 0, 0.7);
}

.shot img {
  display: block;
  width: 100%;
  height: auto;
}

/* Sections */

.section {
  padding: clamp(3rem, 7vw, 5rem) 0;
  border-top: 1px solid var(--line);
}

.section-head {
  margin-bottom: 2rem;
}

.section-head p {
  margin-top: 0.6rem;
  color: var(--fg-muted);
  max-width: var(--measure);
}

.kicker {
  display: block;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.7rem;
}

.grid3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

@media (max-width: 52rem) {
  .grid3 { grid-template-columns: 1fr; }
}

.card {
  padding: 1.4rem 1.4rem 1.5rem;
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.card h3 {
  margin-bottom: 0.6rem;
}

.card p {
  color: var(--fg-muted);
  font-size: 0.95rem;
}

.card .num {
  display: inline-block;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.8rem;
  margin-bottom: 0.9rem;
}

/* Prose pages */

.page {
  padding: clamp(3rem, 7vw, 5rem) 0 clamp(2rem, 5vw, 3.5rem);
}

.page-head {
  margin-bottom: clamp(2rem, 5vw, 3rem);
}

.page-head p {
  margin-top: 0.8rem;
  color: var(--fg-muted);
  max-width: var(--measure);
  font-size: 1.05rem;
}

.prose {
  max-width: var(--measure);
}

.prose > * + * { margin-top: 1rem; }
.prose h2 { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--line); }
.prose h2:first-child { margin-top: 0; padding-top: 0; border-top: 0; }
.prose h3 { margin-top: 2rem; }
.prose p, .prose li { color: var(--fg-muted); }
.prose p strong, .prose li strong { color: var(--fg); font-weight: 600; }
.prose ol, .prose ul { padding-left: 1.4rem; }
.prose li + li { margin-top: 0.45rem; }
.prose pre { margin-top: 0.8rem; }

.callout {
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--accent-dim);
  color: var(--fg-muted);
  font-size: 0.95rem;
}

.callout strong { color: var(--fg); }

/* Doc lists */

.doclist {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.6rem;
}

.doclist li {
  margin: 0;
}

.doclist a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1.05rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg-raised);
  color: var(--fg);
  text-decoration: none;
}

.doclist a:hover { background: var(--bg-hover); border-color: var(--line-strong); text-decoration: none; }

.doclist a span {
  color: var(--fg-faint);
  font-size: 0.85rem;
  font-family: var(--mono);
  white-space: nowrap;
}

/* Two-column table of contents on wide screens */

.with-toc {
  display: grid;
  grid-template-columns: minmax(0, var(--measure)) 12rem;
  gap: 4rem;
  align-items: start;
}

.toc {
  position: sticky;
  top: 4.5rem;
  font-size: 0.88rem;
}

.toc ol {
  list-style: none;
  padding: 0;
  margin: 0;
  border-left: 1px solid var(--line);
}

.toc li + li { margin-top: 0.1rem; }

.toc a {
  display: block;
  padding: 0.3rem 0 0.3rem 0.9rem;
  margin-left: -1px;
  border-left: 1px solid transparent;
  color: var(--fg-muted);
  text-decoration: none;
}

.toc a:hover { color: var(--fg); border-left-color: var(--line-strong); text-decoration: none; }

@media (max-width: 60rem) {
  .with-toc { grid-template-columns: 1fr; gap: 0; }
  .toc { display: none; }
}

/* Footer */

.foot {
  margin-top: clamp(2rem, 6vw, 4rem);
  padding: 2rem 0 2.5rem;
  border-top: 1px solid var(--line);
  color: var(--fg-faint);
  font-size: 0.88rem;
}

.foot .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem 2rem;
}

.foot nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
}

.foot a { color: var(--fg-muted); }
.foot a:hover { color: var(--fg); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}