:root {
  --bg: #fdfdfc;
  --bg-soft: #f4f3ef;
  --bg-code: #f6f5f1;
  --fg: #1c1c1a;
  --fg-soft: #5a5a55;
  --fg-muted: #8a8a82;
  --border: #e2e0d8;
  --accent: #b04030;
  --accent-soft: #f4d8d2;
  --kbd-bg: #ffffff;
  --shadow: 0 1px 0 rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.04);
  --radius: 6px;
  --radius-lg: 12px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, system-ui, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15140f;
    --bg-soft: #1d1c17;
    --bg-code: #1a1915;
    --fg: #ecebe4;
    --fg-soft: #b8b6ad;
    --fg-muted: #8c8a82;
    --border: #2c2b25;
    --accent: #e08070;
    --accent-soft: #3a2622;
    --kbd-bg: #25241f;
    --shadow: 0 1px 0 rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.3);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 120ms ease;
}

a:hover {
  border-bottom-color: var(--accent);
}

h1, h2, h3, h4 {
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--fg);
  margin-top: 2.5em;
  margin-bottom: 0.6em;
  line-height: 1.25;
}

h1 { font-size: 2.4rem; letter-spacing: -0.02em; }
h2 { font-size: 1.6rem; }
h3 { font-size: 1.2rem; }

p { margin: 0.8em 0; }

code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05em 0.35em;
}

pre {
  font-family: var(--mono);
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.55;
  margin: 1.2em 0;
}

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

kbd {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--kbd-bg);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0.05em 0.4em;
}

ul, ol {
  padding-left: 1.4em;
}

li { margin: 0.3em 0; }

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 3em 0;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.2em 0;
  font-size: 0.92rem;
}

th, td {
  text-align: left;
  padding: 0.5em 0.8em;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  font-weight: 600;
  background: var(--bg-soft);
}

td code {
  white-space: nowrap;
}

blockquote {
  margin: 1.2em 0;
  padding: 0.6em 1.2em;
  border-left: 3px solid var(--accent);
  background: var(--bg-soft);
  color: var(--fg-soft);
  border-radius: 0 var(--radius) var(--radius) 0;
}

blockquote p:first-child { margin-top: 0; }
blockquote p:last-child { margin-bottom: 0; }

/* Layout */

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
}

.site-header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  font-family: var(--mono);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--fg);
  border: none;
}

.brand:hover { color: var(--accent); }

.nav {
  display: flex;
  gap: 1.5rem;
  font-size: 0.9rem;
}

.nav a {
  color: var(--fg-soft);
  border: none;
}

.nav a:hover { color: var(--accent); }

.nav a.current { color: var(--fg); font-weight: 500; }

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem;
}

.container-wide {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem;
}

/* Hero */

.hero {
  text-align: center;
  padding: 5rem 1.5rem 3rem;
  max-width: 760px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 3rem;
  margin: 0 0 0.4em;
  letter-spacing: -0.03em;
}

.hero .tagline {
  font-size: 1.2rem;
  color: var(--fg-soft);
  margin: 0 auto 1.6em;
  max-width: 560px;
  line-height: 1.5;
}

.hero-ctas {
  display: flex;
  gap: 0.8rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2rem;
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 500;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--fg);
  transition: all 120ms ease;
}

.btn:hover {
  border-color: var(--fg-muted);
  border-bottom-color: var(--fg-muted);
}

.btn-primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.btn-primary:hover {
  background: var(--fg);
  border-color: var(--fg);
  color: var(--bg);
}

/* Diagram */

.flow {
  display: flex;
  align-items: stretch;
  gap: 0.6rem;
  margin: 3rem 0;
  font-family: var(--mono);
  font-size: 0.85rem;
  flex-wrap: wrap;
}

.flow-step {
  flex: 1 1 200px;
  min-width: 0;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
}

.flow-step-title {
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 0.3rem;
}

.flow-step-body {
  color: var(--fg-soft);
  font-size: 0.78rem;
  line-height: 1.5;
}

.flow-arrow {
  display: flex;
  align-items: center;
  color: var(--fg-muted);
  font-size: 1.2rem;
}

@media (max-width: 720px) {
  .flow-arrow { display: none; }
}

/* Feature grid */

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.feature {
  padding: 1.2rem;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.feature h3 {
  margin: 0 0 0.4em;
  font-size: 1rem;
}

.feature p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--fg-soft);
  line-height: 1.5;
}

/* Step list (tutorial) */

.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 2rem 0;
}

.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 2.6rem;
  margin: 1.5em 0;
}

.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.05em;
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
}

.steps h3 {
  margin-top: 0;
  margin-bottom: 0.3em;
  font-size: 1.1rem;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--fg-muted);
}

.site-footer a {
  color: var(--fg-soft);
  border: none;
}

.site-footer a:hover { color: var(--accent); }

/* Misc */

.lead {
  font-size: 1.1rem;
  color: var(--fg-soft);
  line-height: 1.6;
}

.callout {
  margin: 1.5em 0;
  padding: 1rem 1.2rem;
  background: var(--accent-soft);
  border-radius: var(--radius);
  font-size: 0.92rem;
  color: var(--fg);
}

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

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

.toc {
  margin: 1.5em 0 2.5em;
  padding: 1rem 1.5rem;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.92rem;
}

.toc strong {
  display: block;
  margin-bottom: 0.4em;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--fg-muted);
}

.toc ol { margin: 0; padding-left: 1.4em; }
.toc li { margin: 0.2em 0; }

/* Subtle syntax highlighting (manually applied via spans) */

.tok-c { color: var(--fg-muted); font-style: italic; }
.tok-k { color: #9050a0; }
.tok-s { color: #708050; }
.tok-n { color: var(--fg); }

@media (prefers-color-scheme: dark) {
  .tok-k { color: #c890d8; }
  .tok-s { color: #b0c890; }
}