:root {
  --bg: oklch(16% 0.02 265);
  --bg-raise: oklch(21% 0.025 265);
  --bg-card: oklch(24% 0.03 265);
  --line: oklch(34% 0.03 265);
  --text: oklch(95% 0.01 265);
  --muted: oklch(72% 0.02 265);
  --faint: oklch(58% 0.02 265);
  --accent: oklch(78% 0.16 155);
  --accent-2: oklch(72% 0.15 280);
  --warn: oklch(80% 0.14 70);

  --display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --body: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, monospace;

  --text-hero: clamp(2.6rem, 1.2rem + 5.5vw, 5.5rem);
  --text-h2: clamp(1.6rem, 1.1rem + 2vw, 2.6rem);
  --text-h3: clamp(1.15rem, 1rem + 0.6vw, 1.4rem);
  --text-base: clamp(1rem, 0.96rem + 0.2vw, 1.1rem);

  --space-section: clamp(4rem, 3rem + 6vw, 9rem);
  --maxw: 1080px;
  --radius: 14px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --dur: 320ms;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    radial-gradient(1200px 600px at 80% -10%, oklch(24% 0.05 155 / 0.35), transparent 60%),
    radial-gradient(1000px 500px at -10% 10%, oklch(24% 0.05 280 / 0.3), transparent 55%),
    var(--bg);
  color: var(--text);
  font-family: var(--body);
  font-size: var(--text-base);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.2rem, 5vw, 2.5rem); }
section { padding-block: var(--space-section); border-top: 1px solid var(--line); }
h2 { font-family: var(--display); font-size: var(--text-h2); font-weight: 700; letter-spacing: -0.02em; line-height: 1.05; margin: 0 0 0.4em; }
h3 { font-family: var(--display); font-size: var(--text-h3); font-weight: 500; margin: 0 0 0.4em; }
.eyebrow { font-family: var(--mono); font-size: 0.8rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--accent); margin: 0 0 1rem; }
.lead { color: var(--muted); max-width: 60ch; }

header.nav { position: sticky; top: 0; z-index: 10; backdrop-filter: blur(12px); background: oklch(16% 0.02 265 / 0.7); border-bottom: 1px solid var(--line); }
.nav .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-block: 0.9rem; flex-wrap: wrap; }
.brand { font-family: var(--display); font-weight: 700; letter-spacing: -0.02em; font-size: 1.15rem; }
.brand span { color: var(--accent); }
.nav nav { display: flex; gap: 1.4rem; font-size: 0.9rem; }
.nav nav a { color: var(--muted); }
.nav nav a:hover { color: var(--text); text-decoration: none; }
.right { display: flex; align-items: center; gap: 1rem; }
.langs { display: flex; gap: 0.5rem; font-family: var(--mono); font-size: 0.75rem; }
.langs a { color: var(--faint); text-transform: uppercase; letter-spacing: 0.05em; }
.langs a:hover { color: var(--text); text-decoration: none; }
.langs a[aria-current="true"] { color: var(--accent); }
.gh { font-family: var(--mono); font-size: 0.82rem; padding: 0.4rem 0.8rem; border: 1px solid var(--line); border-radius: 8px; color: var(--text); transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease); }
.gh:hover { border-color: var(--accent); transform: translateY(-1px); text-decoration: none; }
@media (max-width: 760px) { .nav nav { display: none; } }

.hero { border-top: none; padding-top: clamp(3rem, 2rem + 6vw, 6rem); }
.hero h1 { font-family: var(--display); font-size: var(--text-hero); font-weight: 700; line-height: 0.98; letter-spacing: -0.035em; margin: 0.3em 0 0.4em; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero .lead { font-size: clamp(1.1rem, 1rem + 0.6vw, 1.35rem); max-width: 56ch; }
.goals { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-top: 2rem; padding: 0; }
.goals li { list-style: none; font-family: var(--mono); font-size: 0.82rem; padding: 0.45rem 0.85rem; border: 1px solid var(--line); border-radius: 999px; color: var(--muted); background: var(--bg-raise); }
.cta { display: flex; gap: 0.9rem; margin-top: 2.4rem; flex-wrap: wrap; }
.btn { font-family: var(--mono); font-size: 0.9rem; padding: 0.75rem 1.3rem; border-radius: 10px; transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease); }
.btn-primary { background: var(--accent); color: oklch(18% 0.04 155); font-weight: 500; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 30px oklch(78% 0.16 155 / 0.25); text-decoration: none; }
.btn-ghost { border: 1px solid var(--line); color: var(--text); }
.btn-ghost:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-2px); }

.grid { display: grid; gap: 1.1rem; }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 800px) { .cols-2 { grid-template-columns: 1fr; } }
.card { background: linear-gradient(180deg, var(--bg-card), var(--bg-raise)); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.5rem; transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease); }
.card:hover { transform: translateY(-3px); border-color: oklch(40% 0.05 155); }
.card p { color: var(--muted); margin: 0; }
.card .k { font-family: var(--mono); font-size: 0.78rem; color: var(--accent); letter-spacing: 0.05em; }

.axes { margin-top: 2rem; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.axis { display: grid; grid-template-columns: 1.2fr 1.4fr 1.4fr; gap: 1rem; padding: 1.2rem 1.4rem; border-top: 1px solid var(--line); }
.axis:first-child { border-top: none; background: var(--bg-raise); font-family: var(--mono); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--faint); }
.axis strong { font-family: var(--display); font-weight: 500; }
.axis small { color: var(--muted); }
@media (max-width: 720px) { .axis { grid-template-columns: 1fr; gap: 0.3rem; } .axis:first-child { display: none; } .axis strong::before { content: "▸ "; color: var(--accent); } }

.loop { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: stretch; margin-top: 2rem; }
.loop .node { flex: 1 1 140px; background: var(--bg-card); border: 1px solid var(--line); border-radius: 12px; padding: 1rem 1.1rem; }
.loop .node .n { font-family: var(--mono); font-size: 0.72rem; color: var(--accent); }
.loop .node h4 { margin: 0.25rem 0 0.15rem; font-family: var(--display); font-weight: 500; font-size: 1.05rem; }
.loop .node p { margin: 0; color: var(--faint); font-size: 0.85rem; }
.loop .arrow { align-self: center; color: var(--faint); font-family: var(--mono); }
.loopback { margin-top: 0.8rem; font-family: var(--mono); font-size: 0.82rem; color: var(--accent-2); }

.pipe { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.6rem; font-family: var(--mono); font-size: 0.85rem; }
.pipe span { padding: 0.5rem 0.85rem; border: 1px solid var(--line); border-radius: 8px; background: var(--bg-raise); color: var(--muted); }
.pipe span.hot { border-color: var(--accent); color: var(--text); }
.pipe b { color: var(--faint); align-self: center; }

.anatomy { margin-top: 2rem; display: grid; gap: 0.8rem; }
.row { display: grid; grid-template-columns: 200px 1fr; gap: 1.2rem; padding: 1rem 1.2rem; border: 1px solid var(--line); border-radius: 12px; background: var(--bg-raise); align-items: baseline; }
.row .label { font-family: var(--display); font-weight: 500; }
.row .label .pin { display: inline-block; font-family: var(--mono); font-size: 0.65rem; color: var(--warn); border: 1px solid oklch(50% 0.1 70); border-radius: 5px; padding: 0.05rem 0.35rem; margin-left: 0.4rem; vertical-align: middle; }
.row p { margin: 0; color: var(--muted); }
@media (max-width: 720px) { .row { grid-template-columns: 1fr; gap: 0.3rem; } }

.timeline { margin-top: 2rem; display: grid; gap: 0; }
.ms { display: grid; grid-template-columns: 90px 1fr; gap: 1.2rem; padding: 1.1rem 0; border-top: 1px solid var(--line); }
.ms .tag { font-family: var(--mono); font-size: 0.82rem; color: var(--accent); }
.ms .tag .done { color: var(--faint); }
.ms h4 { margin: 0 0 0.2rem; font-family: var(--display); font-weight: 500; }
.ms p { margin: 0; color: var(--muted); font-size: 0.95rem; }

pre { background: oklch(13% 0.02 265); border: 1px solid var(--line); border-radius: 12px; padding: 1.2rem 1.3rem; overflow-x: auto; font-family: var(--mono); font-size: 0.85rem; line-height: 1.7; color: var(--text); }
pre .c { color: var(--faint); }
pre .a { color: var(--accent); }
code { font-family: var(--mono); font-size: 0.9em; background: var(--bg-raise); padding: 0.1rem 0.4rem; border-radius: 5px; }

.stack { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.6rem; }
.stack span { font-family: var(--mono); font-size: 0.8rem; padding: 0.45rem 0.8rem; border: 1px solid var(--line); border-radius: 8px; color: var(--muted); }
.stack span b { color: var(--accent); font-weight: 400; }

.faq { margin-top: 2rem; display: grid; gap: 0.8rem; }
.faq details { border: 1px solid var(--line); border-radius: 12px; background: var(--bg-raise); padding: 0.4rem 1.2rem; }
.faq summary { cursor: pointer; font-family: var(--display); font-weight: 500; padding: 0.8rem 0; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before { content: "+ "; color: var(--accent); font-family: var(--mono); }
.faq details[open] summary::before { content: "− "; }
.faq p { color: var(--muted); margin: 0 0 1rem; }

footer { border-top: 1px solid var(--line); padding-block: 3rem; color: var(--faint); font-size: 0.9rem; }
footer .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}