/* Struxt3D website: home, tutorials, manual. Light by default, dark with the system or the toggle. */
:root {
  color-scheme: light;
  --bg: #f7f9fc;
  --bg-2: #eef2f8;
  --surface: #ffffff;
  --ink: #0d1424;
  --ink-2: #3a4458;
  --muted: #5e6a80;
  --line: #dde3ee;
  --line-2: #c9d2e1;
  --accent: #1f5fe6;
  --accent-2: #0a8fd1;
  --accent-ink: #ffffff;
  --accent-soft: #e6eefe;
  --good: #18794e;
  --good-soft: #e3f5ec;
  --warn: #9a5b00;
  --warn-soft: #fdf1dc;
  --bad: #c42b4b;
  --code-bg: #eef2f8;
  --shadow: 0 1px 2px rgba(13, 20, 36, 0.05), 0 8px 24px rgba(13, 20, 36, 0.06);
  --grad: linear-gradient(135deg, #64d2ff 0%, #2e6bff 100%);
  --font: Geist, 'Segoe UI Variable', 'Segoe UI', system-ui, -apple-system, sans-serif;
  --mono: 'Geist Mono', ui-monospace, 'Cascadia Mono', Consolas, monospace;
  --r: 12px;
  --r-lg: 18px;
  --wrap: 1200px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    color-scheme: dark;
    --bg: #0a0e18;
    --bg-2: #0f1524;
    --surface: #121a2b;
    --ink: #eef2f9;
    --ink-2: #c3cbda;
    --muted: #8d98ad;
    --line: #222c40;
    --line-2: #2f3a52;
    --accent: #64b4ff;
    --accent-2: #64d2ff;
    --accent-ink: #04121a;
    --accent-soft: #14233d;
    --good: #4cd38a;
    --good-soft: #10291e;
    --warn: #ffb347;
    --warn-soft: #2d2210;
    --bad: #ff6b88;
    --code-bg: #182136;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 10px 30px rgba(0, 0, 0, 0.25);
  }
}
:root[data-theme='dark'] {
  color-scheme: dark;
  --bg: #0a0e18;
  --bg-2: #0f1524;
  --surface: #121a2b;
  --ink: #eef2f9;
  --ink-2: #c3cbda;
  --muted: #8d98ad;
  --line: #222c40;
  --line-2: #2f3a52;
  --accent: #64b4ff;
  --accent-2: #64d2ff;
  --accent-ink: #04121a;
  --accent-soft: #14233d;
  --good: #4cd38a;
  --good-soft: #10291e;
  --warn: #ffb347;
  --warn-soft: #2d2210;
  --bad: #ff6b88;
  --code-bg: #182136;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 10px 30px rgba(0, 0, 0, 0.25);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 84px; }
body { margin: 0; font: 16px/1.65 var(--font); color: var(--ink); background: var(--bg); -webkit-font-smoothing: antialiased; overflow-x: hidden; }
img, svg { max-width: 100%; }
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.skip { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--surface); padding: 8px 14px; border-radius: 8px; }
.skip:focus { left: 16px; }

/* ---------------------------------------------------------------- header */
.site-head { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: saturate(1.6) blur(14px); -webkit-backdrop-filter: saturate(1.6) blur(14px); border-bottom: 1px solid var(--line); }
.head-row { display: flex; align-items: center; gap: 28px; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 650; font-size: 18px; letter-spacing: -0.01em; color: var(--ink); text-decoration: none; }
.brand .logo { width: 28px; height: 28px; }
.nav { display: flex; gap: 4px; flex: 1; }
.nav a { color: var(--ink-2); text-decoration: none; font-size: 15px; font-weight: 500; padding: 6px 12px; border-radius: 8px; }
.nav a:hover { background: var(--bg-2); color: var(--ink); }
.nav a[aria-current='page'] { color: var(--accent); background: var(--accent-soft); }
.head-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn { display: inline-grid; place-items: center; width: 40px; height: 40px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); color: var(--ink-2); cursor: pointer; }
.icon-btn:hover { color: var(--ink); border-color: var(--line-2); }
.icon-btn svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.menu-btn { display: none; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 40px; padding: 0 18px; border-radius: 10px; font: 600 15px/1 var(--font); text-decoration: none; border: 1px solid var(--line-2); color: var(--ink); background: var(--surface); cursor: pointer; white-space: nowrap; }
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); color: var(--accent-ink); }
.btn.lg { min-height: 50px; padding: 0 24px; font-size: 16px; border-radius: 12px; }

/* ---------------------------------------------------------------- footer */
.site-foot { margin-top: 96px; border-top: 1px solid var(--line); background: var(--bg-2); font-size: 15px; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; padding-top: 56px; padding-bottom: 40px; }
.foot-grid h2 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin: 4px 0 12px; font-weight: 600; }
.foot-grid > div > a:not(.brand):not(.btn) { display: block; color: var(--ink-2); text-decoration: none; padding: 4px 0; }
.foot-grid > div > a:not(.brand):not(.btn):hover { color: var(--accent); }
.foot-brand p { color: var(--muted); max-width: 30ch; margin: 12px 0 18px; }
.foot-base { display: flex; flex-wrap: wrap; gap: 20px; padding-top: 20px; padding-bottom: 32px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.foot-base a { color: var(--muted); }
.foot-base .link-btn { padding: 0; border: 0; background: none; color: var(--muted); font: inherit; cursor: pointer; }
.foot-base .link-btn:hover { color: var(--ink); text-decoration: underline; }
.prose .link-btn { padding: 0; border: 0; background: none; color: var(--accent); font: inherit; cursor: pointer; text-decoration: underline; }

/* ---------------------------------------------------------------- home & plain pages */
.hero { position: relative; padding: 88px 0 72px; overflow: hidden; }
.hero::before { content: ''; position: absolute; inset: -40% -10% auto; height: 640px; background: radial-gradient(closest-side, color-mix(in srgb, #64d2ff 28%, transparent), transparent 70%), radial-gradient(closest-side at 70% 40%, color-mix(in srgb, #2e6bff 22%, transparent), transparent 70%); pointer-events: none; z-index: -1; }
.hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 600; color: var(--accent); background: var(--accent-soft); padding: 5px 12px; border-radius: 999px; margin: 0 0 20px; }
.hero h1 { font-size: clamp(38px, 5.4vw, 62px); line-height: 1.04; letter-spacing: -0.035em; margin: 0 0 20px; font-weight: 700; text-wrap: balance; }
.hero h1 em { font-style: normal; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .lead { font-size: 20px; color: var(--ink-2); max-width: 36ch; margin: 0 0 32px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-note { margin-top: 18px; color: var(--muted); font-size: 14px; }
.hero-art { position: relative; border-radius: 22px; overflow: hidden; background: #070a14; box-shadow: 0 30px 80px -20px rgba(20, 50, 120, 0.45), 0 0 0 1px rgba(255, 255, 255, 0.06) inset; aspect-ratio: 4 / 3; }
.hero-art svg { display: block; width: 100%; height: 100%; }

.band { padding: 80px 0; }
.band.alt { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.band-head { max-width: 680px; margin-bottom: 40px; }
.band-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.band h2 { font-size: clamp(28px, 3.4vw, 40px); line-height: 1.12; letter-spacing: -0.025em; margin: 0 0 14px; text-wrap: balance; }
.band-head p { font-size: 18px; color: var(--ink-2); margin: 0; }

.steps-row { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; counter-reset: s; }
.step-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); padding: 22px; counter-increment: s; }
.step-card::before { content: counter(s); display: grid; place-items: center; width: 32px; height: 32px; border-radius: 10px; background: var(--grad); color: #fff; font-weight: 700; margin-bottom: 14px; }
.step-card h3 { font-size: 17px; margin: 0 0 6px; }
.step-card p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.5; }

.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); padding: 26px; }
.feature .ic { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent); margin-bottom: 16px; }
.feature .ic svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.feature h3 { margin: 0 0 8px; font-size: 18px; letter-spacing: -0.01em; }
.feature p { margin: 0; color: var(--ink-2); font-size: 15.5px; }

.code-strip { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; }
.code-pill { display: block; text-decoration: none; color: var(--ink); background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 16px; transition: border-color 0.15s; }
.code-pill:hover { border-color: var(--accent); }
.code-pill b { display: block; font-size: 16px; }
.code-pill span { display: block; color: var(--muted); font-size: 13.5px; line-height: 1.4; margin-top: 4px; }

.cta-band { text-align: center; padding: 72px 24px; border-radius: 28px; background: var(--grad); color: #fff; }
.cta-band h2 { color: #fff; }
.cta-band p { font-size: 18px; opacity: 0.92; margin: 0 auto 28px; max-width: 46ch; }
.cta-band .btn { background: #fff; color: #0d1424; border-color: #fff; }

.page-head { padding: 64px 0 32px; }
.page-head h1 { font-size: clamp(34px, 4.4vw, 50px); letter-spacing: -0.03em; line-height: 1.08; margin: 0 0 14px; }
.page-head .lead { font-size: 19px; color: var(--ink-2); max-width: 60ch; margin: 0; }

/* ---------------------------------------------------------------- cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; margin: 20px 0 8px; }
.card { display: flex; flex-direction: column; gap: 6px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); padding: 20px; text-decoration: none; color: var(--ink); transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s; }
a.card:hover { border-color: var(--accent); box-shadow: var(--shadow); transform: translateY(-1px); }
.card-kicker { font-size: 12.5px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.07em; color: var(--accent); }
.card-title { font-size: 17.5px; font-weight: 650; letter-spacing: -0.01em; line-height: 1.3; }
.card-text { color: var(--muted); font-size: 15px; line-height: 1.5; flex: 1; }
.card-meta { display: flex; gap: 12px; font-size: 13px; color: var(--muted); margin-top: 6px; }
.card-meta span + span::before { content: '·'; margin-right: 12px; }
.card-links { display: flex; gap: 16px; margin-top: 8px; font-size: 14.5px; font-weight: 600; }
.filter { display: flex; flex-wrap: wrap; gap: 8px; margin: 8px 0 4px; }
.filter button { font: 500 14.5px var(--font); padding: 7px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); cursor: pointer; }
.filter button[aria-pressed='true'] { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

/* ---------------------------------------------------------------- docs layout */
.doc { display: grid; grid-template-columns: 240px minmax(0, 1fr) 200px; gap: 48px; padding-top: 40px; align-items: start; }
.doc.hub { grid-template-columns: minmax(0, 1fr); max-width: 1100px; }
.doc:not(:has(.toc)) { grid-template-columns: 240px minmax(0, 1fr); }
.doc.hub:not(:has(.toc)) { grid-template-columns: minmax(0, 1fr); }
.doc-side, .toc { position: sticky; top: 88px; max-height: calc(100vh - 110px); overflow: auto; font-size: 14.5px; }
.side-box summary { font-weight: 650; font-size: 13px; text-transform: uppercase; letter-spacing: 0.07em; color: var(--muted); cursor: pointer; list-style: none; margin-bottom: 10px; }
.side-box summary::-webkit-details-marker { display: none; }
.doc-side ul, .toc ul { list-style: none; margin: 0; padding: 0; }
.doc-side li a { display: block; padding: 6px 10px; border-radius: 8px; color: var(--ink-2); text-decoration: none; line-height: 1.35; }
.doc-side li a:hover { background: var(--bg-2); color: var(--ink); }
.doc-side li a[aria-current='page'] { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.side-all { display: inline-block; margin: 12px 10px 0; font-size: 14px; font-weight: 600; }
.toc p { font-weight: 650; font-size: 13px; text-transform: uppercase; letter-spacing: 0.07em; color: var(--muted); margin: 0 0 10px; }
.toc a { display: block; padding: 4px 0 4px 12px; border-left: 2px solid var(--line); color: var(--muted); text-decoration: none; line-height: 1.4; }
.toc a:hover, .toc a.on { color: var(--accent); border-left-color: var(--accent); }

.crumbs ol { display: flex; flex-wrap: wrap; gap: 6px; list-style: none; padding: 0; margin: 0 0 18px; font-size: 14px; color: var(--muted); }
.crumbs li + li::before { content: '/'; margin-right: 6px; color: var(--line-2); }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--accent); }
.doc-head .kicker { margin: 0 0 8px; font-size: 13px; font-weight: 650; letter-spacing: 0.08em; text-transform: uppercase; color: var(--accent); }
.doc-head h1 { font-size: clamp(30px, 3.6vw, 44px); line-height: 1.1; letter-spacing: -0.03em; margin: 0 0 14px; text-wrap: balance; }
.doc-head .lead { font-size: 19px; color: var(--ink-2); margin: 0 0 18px; }
.facts { display: flex; flex-wrap: wrap; gap: 8px 20px; font-size: 14px; color: var(--muted); padding-bottom: 22px; border-bottom: 1px solid var(--line); }
.fact b { font-weight: 600; color: var(--ink-2); margin-right: 4px; }
.cta-box { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin: 24px 0 0; padding: 16px 18px; border-radius: var(--r); background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent); }
.cta-box b { display: block; }
.cta-box span { color: var(--ink-2); font-size: 14.5px; }

/* ---------------------------------------------------------------- prose */
.prose { font-size: 17px; color: var(--ink); max-width: 760px; }
.doc.hub .prose { max-width: none; }
.prose > :first-child { margin-top: 28px; }
.prose h2 { font-size: 27px; line-height: 1.2; letter-spacing: -0.02em; margin: 52px 0 14px; }
.prose h3 { font-size: 20px; line-height: 1.3; letter-spacing: -0.01em; margin: 34px 0 10px; }
.prose h4 { font-size: 17px; margin: 26px 0 8px; }
.prose h2, .prose h3 { position: relative; }
.prose .anchor { position: absolute; left: -1.1em; color: var(--line-2); text-decoration: none; opacity: 0; font-weight: 400; }
.prose h2:hover .anchor, .prose h3:hover .anchor { opacity: 1; }
.prose p, .prose ul, .prose ol { margin: 0 0 18px; }
.prose li { margin: 6px 0; }
.prose li > ul, .prose li > ol { margin: 6px 0; }
.prose strong { font-weight: 650; }
.prose code { font: 0.88em var(--mono); background: var(--code-bg); padding: 2px 6px; border-radius: 6px; }
.prose pre { font: 14px/1.6 var(--mono); background: var(--code-bg); padding: 16px 18px; border-radius: var(--r); overflow-x: auto; }
.prose pre code { background: none; padding: 0; }
.prose kbd { font: 600 0.82em var(--mono); background: var(--surface); border: 1px solid var(--line-2); border-bottom-width: 2px; border-radius: 6px; padding: 1px 6px; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
.prose blockquote { margin: 0 0 18px; padding: 4px 0 4px 18px; border-left: 3px solid var(--line-2); color: var(--ink-2); }
.prose .ui { font-weight: 600; color: var(--ink); background: var(--bg-2); border: 1px solid var(--line); border-radius: 6px; padding: 0 6px; font-size: 0.94em; white-space: nowrap; }

.prose table { width: 100%; border-collapse: collapse; margin: 0 0 22px; font-size: 15.5px; display: block; overflow-x: auto; }
.prose th, .prose td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose thead th { font-weight: 650; color: var(--ink-2); background: var(--bg-2); border-bottom: 1px solid var(--line-2); white-space: nowrap; }
.prose td.num, .prose th.num { text-align: right; font-variant-numeric: tabular-nums; }

.prose figure { margin: 26px 0; }
.prose figure .fig { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; color: var(--ink); }
.prose figure .fig svg { display: block; width: 100%; height: auto; }
.prose figcaption { font-size: 14.5px; color: var(--muted); margin-top: 10px; }

.note, .tip, .warn, .key { border-radius: var(--r); padding: 14px 18px; margin: 0 0 20px; border: 1px solid var(--line); background: var(--surface); font-size: 16px; }
.note > :last-child, .tip > :last-child, .warn > :last-child, .key > :last-child { margin-bottom: 0; }
.note::before, .tip::before, .warn::before, .key::before { display: block; font-size: 12.5px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 4px; }
.note { background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 22%, transparent); }
.note::before { content: 'Note'; color: var(--accent); }
.tip { background: var(--good-soft); border-color: color-mix(in srgb, var(--good) 25%, transparent); }
.tip::before { content: 'Tip'; color: var(--good); }
.warn { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 30%, transparent); }
.warn::before { content: 'Watch out'; color: var(--warn); }
.key::before { content: 'Key idea'; color: var(--accent); }
.key { border-left: 4px solid var(--accent); }

.formula { font-family: var(--mono); font-size: 15.5px; background: var(--code-bg); border-radius: var(--r); padding: 14px 18px; margin: 0 0 20px; overflow-x: auto; white-space: nowrap; }
.formula small { display: block; font-family: var(--font); color: var(--muted); font-size: 13.5px; white-space: normal; margin-top: 4px; }
.prose math { font-size: 1.08em; }
.prose math[display='block'] { margin: 0 0 20px; overflow-x: auto; overflow-y: hidden; padding: 12px 0; }

/* Numbered how-to steps */
.prose ol.steps { list-style: none; padding: 0; counter-reset: st; }
.prose ol.steps > li { position: relative; padding: 0 0 18px 50px; margin: 0; counter-increment: st; }
.prose ol.steps > li::before { content: counter(st); position: absolute; left: 0; top: 0; width: 32px; height: 32px; border-radius: 10px; background: var(--accent-soft); color: var(--accent); font-weight: 700; display: grid; place-items: center; font-size: 15px; }
.prose ol.steps > li::after { content: ''; position: absolute; left: 15.5px; top: 38px; bottom: 6px; width: 1px; background: var(--line); }
.prose ol.steps > li:last-child::after { display: none; }

.chapters { list-style: none; padding: 0; margin: 20px 0; counter-reset: ch; display: grid; gap: 10px; }
.chapters li { counter-increment: ch; }
.chapters a { display: grid; grid-template-columns: 44px 1fr; grid-template-rows: auto auto; column-gap: 14px; padding: 16px 18px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); text-decoration: none; color: var(--ink); }
.chapters a::before { content: counter(ch, decimal-leading-zero); grid-row: span 2; font: 600 15px var(--mono); color: var(--accent); padding-top: 2px; }
.chapters a:hover { border-color: var(--accent); }
.ch-title { font-weight: 650; font-size: 17px; }
.ch-text { color: var(--muted); font-size: 15px; }

details.faq { border: 1px solid var(--line); border-radius: var(--r); background: var(--surface); padding: 0 18px; margin: 0 0 10px; }
details.faq summary { cursor: pointer; font-weight: 600; padding: 16px 0; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
details.faq summary::after { content: '+'; color: var(--muted); font-weight: 400; font-size: 22px; line-height: 1; }
details.faq[open] summary::after { content: '–'; }
details.faq summary::-webkit-details-marker { display: none; }
details.faq > :not(summary) { margin-top: 0; }

.related { margin-top: 56px; padding-top: 28px; border-top: 1px solid var(--line); }
.related-h { font-size: 20px; margin: 0; }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 40px; }
.pager a { display: block; padding: 16px 18px; border: 1px solid var(--line); border-radius: var(--r); text-decoration: none; color: var(--ink); font-weight: 600; background: var(--surface); }
.pager a:hover { border-color: var(--accent); }
.pager a span { display: block; font-size: 13px; color: var(--muted); font-weight: 500; margin-bottom: 2px; }
.pager .next { text-align: right; grid-column: 2; }

/* ---------------------------------------------------------------- responsive */
@media (max-width: 1180px) {
  .doc { grid-template-columns: 220px minmax(0, 1fr); }
  .toc { display: none; }
  .steps-row { grid-template-columns: repeat(3, 1fr); }
  .code-strip { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 920px) {
  .nav { display: none; position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; padding: 12px 16px 18px; background: var(--bg); border-bottom: 1px solid var(--line); box-shadow: var(--shadow); }
  .nav.open { display: flex; }
  .nav a { padding: 12px; font-size: 16px; }
  .menu-btn { display: inline-grid; }
  .head-row { justify-content: space-between; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .features { grid-template-columns: 1fr 1fr; }
  .doc, .doc:not(:has(.toc)) { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .doc-side { position: static; max-height: none; order: 2; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--line); }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .wrap { padding: 0 16px; }
  .head-row { gap: 12px; }
  .head-actions .btn { padding: 0 12px; font-size: 14px; }
  .hero { padding: 48px 0 40px; }
  .hero .lead { font-size: 18px; }
  .band { padding: 56px 0; }
  .features, .steps-row { grid-template-columns: 1fr; }
  .code-strip { grid-template-columns: 1fr 1fr; }
  .foot-grid { grid-template-columns: 1fr; gap: 28px; }
  .prose { font-size: 16.5px; }
  .prose h2 { font-size: 23px; }
  .cta-box { flex-direction: column; align-items: flex-start; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { grid-column: 1; }
  .cta-band { border-radius: 20px; padding: 48px 20px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }
@media print {
  .site-head, .site-foot, .doc-side, .toc, .cta-box, .pager { display: none !important; }
  .doc { display: block; }
}