/* M — the product page (ported from ark-v2-m-auv). Tokens, header, menu, footer: site.css. *//* Arkeocean — shared by every page: tokens, base, header, the site menu, footer.
   Palette from the logo: black, white, signal red #f2473b. Type: Archivo (wide, like the wordmark) +
   IBM Plex Mono for labels. */

:root {
	--bg: #000;
	--fg: #f4f3f1;
	--fg-2: rgba( 244, 243, 241, 0.74 );
	--fg-3: rgba( 244, 243, 241, 0.5 );
	--line: rgba( 244, 243, 241, 0.18 );
	--red: #f2473b;
	--glass: rgba( 6, 12, 18, 0.42 );
	--paper: #eceef1;
	--ink: #0b0d10;
	--ink-2: rgba( 11, 13, 16, 0.62 );
	--gutter: clamp( 16px, 4.2vw, 72px );
	--font: 'Archivo', system-ui, -apple-system, 'Segoe UI', sans-serif;
	--explanation-size: clamp( 20px, 2.1vw, 28px );
	--mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;
	--header-h: 72px;
	--notch: 22px;
	color-scheme: dark;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: auto; -webkit-text-size-adjust: 100%; }
html.menu-open { overflow: hidden; }
body {
	background: var(--bg);
	color: var(--fg);
	font-family: var(--font);
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	overflow-x: hidden;
}
a { color: inherit; }
img { display: block; max-width: 100%; }
:focus-visible { outline: 2px solid var(--red); outline-offset: 3px; border-radius: 2px; }

.cta {
	display: inline-flex; align-items: center; gap: 0.6em; padding: 11px 18px; border: 1px solid var(--line); border-radius: 999px;
	font-family: var(--mono); font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase;
	color: var(--fg); text-decoration: none; transition: border-color 0.2s, background 0.2s;
}
.cta:hover, .cta:focus-visible { border-color: var(--red); background: rgba( 242, 71, 59, 0.12 ); }
.cta-solid { background: var(--fg); color: var(--ink); border-color: var(--fg); }
.cta-solid:hover, .cta-solid:focus-visible { background: var(--red); color: var(--fg); border-color: var(--red); }

/* ---------------------------------------------------------------- header */
.site-header {
	position: fixed; top: 0; left: 0; right: 0; z-index: 40; height: var(--header-h);
	display: flex; align-items: center; justify-content: space-between; padding: 0 var(--gutter);
	pointer-events: none;
}
.site-header > * { pointer-events: auto; }
.brand img { height: 20px; width: auto; }
.header-actions { display: flex; align-items: center; gap: 22px; }
.header-link { font-family: var(--mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; text-decoration: none; color: var(--fg-2); transition: color 0.2s; }
.header-link:hover, .header-link:focus-visible { color: var(--fg); }
.menu-button {
	display: inline-flex; align-items: center; gap: 10px; height: 34px; padding: 0 16px 0 14px; border: 0; cursor: pointer;
	background: var(--paper); color: var(--ink); font-family: var(--mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase;
	clip-path: polygon( 0 0, calc( 100% - 10px ) 0, 100% 10px, 100% 100%, 0 100% );
	transition: background 0.2s, color 0.2s;
}
.menu-button:hover, .menu-button:focus-visible { background: var(--fg); }
.menu-dots { display: grid; grid-template-columns: repeat( 2, 4px ); gap: 2px; }
.menu-dots i { width: 4px; height: 4px; background: currentColor; }
.menu-button:hover .menu-dots i:nth-child( 1 ), .menu-button:hover .menu-dots i:nth-child( 4 ) { background: var(--red); }

/* ---------------------------------------------------------------- menu (inspired by hubtown.co.in) */
.menu-backdrop {
	position: fixed; inset: 0; z-index: 60; background: rgba( 0, 0, 0, 0.55 ); backdrop-filter: blur( 3px ); -webkit-backdrop-filter: blur( 3px );
	opacity: 0; transition: opacity 0.4s ease;
}
.site-menu {
	position: fixed; z-index: 61; top: 12px; right: 12px; width: min( 460px, calc( 100% - 24px ) ); max-height: calc( 100% - 24px ); display: flex;
	transform: translateX( 24px ); opacity: 0;
	transition: transform 0.5s cubic-bezier( 0.2, 0.8, 0.2, 1 ), opacity 0.35s ease;
}
/* the panel, its top-right corner notched; the Close tab sits in the notch */
.menu-panel {
	position: relative; flex: 1; display: flex; flex-direction: column; padding: 30px 32px 22px;
	background: var(--paper); color: var(--ink);
	clip-path: polygon( 0 0, calc( 100% - 128px ) 0, calc( 100% - 128px + var(--notch) ) var(--notch), 100% var(--notch), 100% 100%, 0 100% );
	overflow-y: auto; overscroll-behavior: contain;
}
/* (closed: out of the layout; `display` here would otherwise override the hidden attribute) */
.site-menu[hidden], .menu-backdrop[hidden] { display: none; }
html.menu-open .menu-backdrop { opacity: 1; }
html.menu-open .site-menu { transform: none; opacity: 1; }
.menu-close {
	position: absolute; z-index: 1; top: 0; right: 0; height: calc( var(--notch) - 3px ); width: 104px; border: 0; cursor: pointer;
	display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding-left: 10px;
	background: var(--ink); color: var(--paper); font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase;
	clip-path: polygon( 16px 0, 100% 0, 100% 100%, 0 100%, 0 calc( 100% - 3px ) );
}
.menu-kicker { display: flex; align-items: center; gap: 10px; font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-2); }
.menu-kicker i { width: 7px; height: 7px; background: var(--red); }
.menu-main { list-style: none; margin: 30px 0 72px; display: grid; gap: 2px; }
.menu-main a {
	display: inline-block; text-decoration: none; text-transform: uppercase; color: var(--ink);
	font-weight: 800; font-stretch: 104%; font-size: clamp( 40px, 4.6vw, 64px ); line-height: 0.96; letter-spacing: -0.02em;
	transition: color 0.2s;
}
/* every link ends on the red full stop of the logo; the current page is greyed */
.menu-main a::after { content: ''; display: inline-block; width: 0.18em; height: 0.18em; margin-left: 0.14em; background: var(--red); vertical-align: 0.1em; }
.menu-main a:hover, .menu-main a:focus-visible { color: var(--red); }
.menu-main a[aria-current='page'] { color: var(--ink-2); }
.menu-foot { margin-top: 22px; display: flex; justify-content: space-between; align-items: center; font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-2); }
.menu-foot a { color: var(--ink); display: inline-flex; }
.menu-foot a:hover { color: var(--red); }

/* ---------------------------------------------------------------- footer */
.site-footer { position: relative; z-index: 20; background: #000; border-top: 1px solid var(--line); }
.footer-inner { padding: 64px var(--gutter) 56px; display: grid; gap: 20px; justify-items: start; }
.footer-inner img { height: 22px; width: auto; }
.footer-line { color: var(--fg-2); font-size: 18px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 10px 26px; font-family: var(--mono); font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; }
.footer-links a { text-decoration: none; color: var(--fg-2); }
.footer-links a:hover, .footer-links a:focus-visible { color: var(--fg); }
.fine { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; color: var(--fg-3); text-transform: uppercase; }

/* ---------------------------------------------------------------- ?embed: a page shown inside the slides */
html.embed .site-header, html.embed .site-footer, html.embed .site-menu, html.embed .menu-backdrop, html.embed .scroll-hint { display: none !important; }
html.embed { scrollbar-width: none; }
html.embed::-webkit-scrollbar { display: none; }

@media ( max-width: 820px ) {
	:root { --header-h: 60px; }
	.brand img { height: 16px; }
	.header-link { display: none; }
	.menu-panel { padding: 26px 22px 18px; }
}

@media ( prefers-reduced-motion: reduce ) {
	.site-menu, .menu-backdrop { transition: none; }
}

/* Keep controls clear of phone cutouts and provide comfortable touch targets. */
:root { --safe-top:env(safe-area-inset-top,0px); }
.site-header { padding-top:var(--safe-top); padding-left:max(var(--gutter),env(safe-area-inset-left,0px)); padding-right:max(var(--gutter),env(safe-area-inset-right,0px)); }
.site-menu { top:calc(12px + var(--safe-top)); right:max(12px,env(safe-area-inset-right,0px)); max-height:calc(100% - 24px - var(--safe-top) - env(safe-area-inset-bottom,0px)); }
.footer-inner { padding-bottom:calc(56px + env(safe-area-inset-bottom,0px)); }
@media(max-width:820px) {
  :root { --header-h:calc(60px + var(--safe-top)); }
  .brand { min-height:44px; display:flex; align-items:center; }
  .menu-button,.menu-close { min-height:44px; }
  .menu-main a { min-height:44px; display:inline-flex; align-items:center; }
  .cta { min-height:44px; }
}
@media(max-height:500px) and (orientation:landscape) {
  .menu-main { margin-bottom:24px; }
  .menu-main a { font-size:36px; }
}
/* Keep every menu item, including M Platform, on a single line. Size the
   lettering from the actual panel width rather than the browser width. */
.menu-main { container-type:inline-size; }
.menu-main a { white-space:nowrap; font-size:min(64px,11cqw); }
@media(max-height:500px) and (orientation:landscape) {
  .menu-main a { font-size:min(36px,11cqw); }
}
/* Match the compact desktop Close tab visually on phones, with an invisible
   44px touch area below it. Keep desktop geometry unchanged. */
@media(max-width:820px) {
  .menu-close { height:44px; min-height:44px; clip-path:none; background:transparent; align-items:flex-start; padding-top:3px; isolation:isolate; }
  .menu-close::before { content:''; position:absolute; top:0; left:0; right:0; height:calc(var(--notch) - 3px); background:var(--ink); clip-path:polygon(16px 0,100% 0,100% 100%,0 100%,0 calc(100% - 3px)); z-index:-1; pointer-events:none; }
}
:root {
  --dark: #050607;
  --light: #f2f0ec;
  --accent: #f2473b;
  --fg-1: #f6f4f2;
  --fg-2: #cccac8;
  --fg-3: #85827e;
  --fg-4: #4a4745;
  --line: rgba(246, 244, 242, .55);
  --chip: rgba(30, 29, 28, .78);
  --margin: clamp(16px, 4vw, 64px);
}
body.is-light {
  --fg-1: #1d1c1b;
  --fg-2: #3b3936;
  --fg-3: #706d6a;
  --fg-4: #b4b1ad;
  --line: rgba(29, 28, 27, .5);
  --chip: rgba(255, 255, 255, .8);
}
body {
  background: var(--dark);
  color: var(--fg-1);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---------- fixed layers ---------- */
#glow { position: fixed; inset: 0; z-index: 0; pointer-events: none; background: radial-gradient(52% 58% at var(--gx, 70%) 52%, rgba(160, 175, 200, .13), transparent 72%); }
#scene { position: fixed; inset: 0; width: 100%; height: 100lvh; display: block; z-index: 0; transition: opacity .6s; }
#scene { touch-action: pan-y; }
body.can-drag #scene { cursor: grab; }
body.dragging, body.dragging #scene { cursor: grabbing; }
#drag-hint { position: fixed; z-index: 5; top: 0; left: 0; width: 60px; display: flex; flex-direction: column; align-items: center; color: var(--fg-2); pointer-events: none; opacity: 0; transition: opacity .6s; will-change: transform, opacity; }
#drag-hint.show { opacity: 1; }
#drag-hint .gesture { display: flex; align-items: center; gap: 4px; height: 60px; }
#drag-hint .arc { width: 18px; height: 56px; overflow: visible; }
#drag-hint .arc path { fill: none; stroke: currentColor; stroke-width: 1.25; stroke-dasharray: 3 4; opacity: .5; }
#drag-hint .arc path.tip { stroke-dasharray: none; stroke-linecap: round; stroke-linejoin: round; }
#drag-hint .hand { width: 28px; height: 28px; fill: currentColor; filter: drop-shadow(0 2px 6px rgba(0, 0, 0, .55)); transform-origin: 50% 85%; animation: swipe 2.4s cubic-bezier(.45, 0, .55, 1) infinite; }
@keyframes swipe { 0%, 100% { transform: translateY(-13px) rotate(-8deg); } 50% { transform: translateY(13px) rotate(8deg); } }
#drag-hint span { margin-top: 6px; text-align: center; line-height: 1.35; font-family: var(--mono); font-size: 10px; letter-spacing: .04em; color: var(--fg-3); }
#leaders { position: fixed; inset: 0; width: 100%; height: 100lvh; pointer-events: none; z-index: 2; overflow: visible; }
#leaders path { fill: none; stroke: var(--line); stroke-width: 1; }
#leaders circle.ring { fill: none; stroke-width: 1.25; }
#leaders circle.dot { stroke: none; }
#labels { position: fixed; inset: 0; pointer-events: none; z-index: 3; }
.label {
  position: absolute; top: 0; left: 0;
  width: max-content; max-width: 280px;
  pointer-events: auto;
  cursor: default;
  opacity: 0;
  will-change: transform, opacity;
}
.label.right { text-align: right; }
.label .name {
  display: inline-flex; align-items: center; gap: .5em;
  font-weight: 700; font-size: 15px; line-height: 1.1; letter-spacing: -.005em;
  color: var(--fg-1);
}
.label.right .name { flex-direction: row-reverse; }
.label .sw { width: 9px; height: 9px; border-radius: 50%; flex: none; background: var(--c); }
.label .meta { display: block; margin-top: 3px; white-space: nowrap; font-family: var(--mono); font-size: 10.5px; line-height: 1.35; color: var(--fg-3); }
.label:hover .name { color: var(--c); }
.label.float { width: max-content; max-width: none; padding: 6px 10px 7px; border-radius: 8px; background: var(--chip); backdrop-filter: blur(8px); }
.label.float .meta { white-space: nowrap; }
@media (max-width: 819px) {
  .label.float { max-width: 150px; padding: 3px 7px; border-radius: 6px; }
  .label .name { font-size: 11.5px; gap: .4em; }
  .label .sw { width: 7px; height: 7px; }
  .label .meta { display: none; }
}

/* ---------- chapter nav ---------- */

#chapters.hidden { opacity: 0; pointer-events: none; }
#chapters {
  transition: opacity .4s;
  position: fixed; z-index: 10; right: var(--margin); bottom: var(--margin);
  width: min(320px, calc(100% - 2 * var(--margin)));
  padding: 12px 14px 14px; border-radius: 14px;
  background: var(--chip); backdrop-filter: blur(10px);
  font-family: var(--mono); font-size: 10.5px; color: var(--fg-3);
}
#chapters .row { display: flex; justify-content: space-between; margin-bottom: 9px; }
#chapters .row b { font-weight: 500; color: var(--fg-1); text-transform: uppercase; letter-spacing: .06em; }
#chapters .track { position: relative; height: 12px; display: flex; gap: 3px; }
#chapters .track a { flex: 1; position: relative; border-left: 1px solid var(--fg-4); background-image: linear-gradient(to right, var(--fg-4) 1px, transparent 1px); background-size: 12.5% 6px; background-repeat: repeat-x; background-position: 0 3px; }
#chapters .track a:last-child { border-right: 1px solid var(--fg-4); }
#chapters .cursor { position: absolute; top: -2px; width: 3px; height: 16px; border-radius: 3px; background: var(--accent); left: 0; will-change: transform; }
@media (max-width: 819px) { #chapters { display: none; } }

/* ---------- loader ---------- */
#loader { position: fixed; inset: 0; z-index: 20; display: grid; place-items: center; background: var(--dark); transition: opacity .8s; font-family: var(--mono); font-size: 12px; color: #85827e; }
#loader.done { opacity: 0; pointer-events: none; }
#loader .bar { width: 180px; height: 2px; margin-top: 12px; background: #2c2a28; overflow: hidden; }
#loader .bar i { display: block; height: 100%; width: 0; background: var(--accent); }

/* ---------- sections ---------- */
main { position: relative; z-index: 4; pointer-events: none; }
main a, main button, .parts-list { pointer-events: auto; }
section { position: relative; }
.section-inner { min-height: 100lvh; padding: calc(var(--margin) + 56px) var(--margin) var(--margin); display: flex; flex-direction: column; }
.eyebrow { font-family: var(--mono); font-size: 12px; color: var(--fg-3); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 1.1em; }
h1, h2 { font-weight: 640; font-stretch: 112%; letter-spacing: -.035em; line-height: .9; }
.dot { color: var(--c, var(--accent)); }

#intro .section-inner { justify-content: space-between; gap: clamp(180px, 30svh, 360px); }
#intro h1 { font-size: clamp(48px, 10vw, 156px); }
#intro .intro-tagline { margin-top: .9em; font-size: var(--explanation-size); line-height: 1.25; font-weight: 700; color: var(--fg); }
#intro p.lead { max-width: 38rem; margin-top: 0; font-size: var(--explanation-size); line-height: 1.25; font-weight: 600; color: var(--fg-2); }
#intro .intro-highlights { display: flex; flex-wrap: nowrap; gap: clamp(8px, 2.7vw, 28px); margin-top: 20px; color: var(--accent); font-size: clamp(22px, 2vw, 28px); font-weight: 650; }
#deployment { height: 1000svh; }
#deployment .deployment-scene-copy { position: sticky; top: 0; height: 100svh; padding: calc(var(--margin) + 52px) var(--margin) var(--margin); }
#deployment h2 { max-width: 8.5em; font-size: clamp(34px, 4.3vw, 64px); line-height: .98; }
#intro .intro-highlights span { white-space: nowrap; }
.deployment-benefits { position: absolute; left: var(--margin); top: calc(var(--margin) + 52px); max-width: 36%; opacity: 0; }
.deployment-benefits p { margin-top: 22px; font-size: clamp(19px, 1.9vw, 26px); line-height: 1.4; color: var(--fg-2); }
.deployment-specs { margin-top: 24px; font-family: var(--mono); color: var(--accent); font-size: 13px; }
@media (max-width: 819px) {
  #intro .intro-highlights { font-size: clamp(10px, 2.9vw, 22px); }
  .deployment-benefits { max-width: calc(100% - var(--margin) * 2); }
  #deployment h2 { font-size: 34px; }
  .deployment-benefits p { font-size: 18px; }
}
#field { height: 1360svh; }
#field .operation-copy { position: sticky; top: 0; height: 100svh; padding: calc(var(--margin) + 44px) var(--margin) var(--margin); text-align: center; }
#field h2 { max-width: 18em; margin: 0 auto; font-size: clamp(32px, 4.2vw, 62px); line-height: 1; }
#field .operation-copy > p { margin: 14px auto 0; max-width: 42rem; font-size: clamp(17px, 1.7vw, 23px); color: var(--fg-2); }
.operation-stages { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px 24px; margin-top: 24px; list-style: none; font-family: var(--mono); font-size: 11px; }
.operation-stages li { color: var(--fg-3); padding-bottom: 8px; border-bottom: 2px solid transparent; transition: color .3s, border-color .3s; }
.operation-stages li.is-active { color: #b1e4da; border-color: #b1e4da; }
.operation-caption { position: absolute; bottom: 100px; left: var(--margin); right: var(--margin); display: flex; flex-direction: column; gap: 10px; align-items: center; }
.operation-caption b { font-size: clamp(24px, 2.5vw, 34px); }
.operation-caption span { max-width: 36rem; font-size: clamp(17px, 1.7vw, 22px); line-height: 1.35; color: var(--fg-2); }
#operation-sensing { min-height: 1.5em; color: #8ce4cc; font-family: var(--mono); font-size: 11px; transition: opacity .3s; }
@media (max-width: 819px) {
  #field .operation-copy { padding-top: 100px; }
  .operation-caption { bottom: 30px; }
  .operation-stages { gap: 8px 14px; margin-top: 18px; font-size: 10px; }
}
.specs { display: flex; flex-wrap: wrap; gap: 6px 26px; margin-top: 28px; font-family: var(--mono); font-size: 12px; color: var(--fg-3); }
.specs b { color: var(--fg-1); font-weight: 500; }
.scroll-hint { margin-top: 36px; font-family: var(--mono); font-size: 11px; color: var(--fg-3); display: flex; align-items: center; gap: 10px; }
.scroll-hint i { display: block; width: 1px; height: 28px; background: linear-gradient(var(--fg-3), transparent); animation: drip 1.8s ease-in-out infinite; transform-origin: top; }
@keyframes drip { 0% { transform: scaleY(0); } 60% { transform: scaleY(1); opacity: 1; } 100% { transform: scaleY(1); opacity: 0; } }

#payload { height: 560lvh; }
#payload .sticky { position: sticky; top: 0; height: 100lvh; padding: calc(var(--margin) + 40px) var(--margin) var(--margin); display: flex; flex-direction: column; align-items: center; text-align: center; }
#payload h2 { font-size: clamp(34px, 4.2vw, 66px); }
#payload .claim { margin-top: .55em; font-size: var(--explanation-size); font-weight: 700; color: var(--accent); }
#payload .ecosystem-copy { max-width: 44rem; margin-top: .8em; font-size: clamp(17px, 1.65vw, 22px); line-height: 1.4; color: var(--fg-2); }
#pay-captions .payload-category { max-width: 145px; white-space: normal; text-align: center; }
@media (max-width: 819px) {
  #pay-captions .payload-category { max-width: 94px; font-size: 9px; }
  #payload .ecosystem-copy { font-size: 16px; }
}
#pay-captions { position: fixed; inset: 0; pointer-events: none; z-index: 3; }
#pay-captions div { position: absolute; top: 0; left: 0; transform-origin: 50% 0; white-space: nowrap; font-family: var(--mono); font-size: 10.5px; letter-spacing: .04em; color: var(--fg-3); opacity: 0; transition: color .4s; }
#pay-captions div.on { color: var(--fg-1); }
#pay-captions div.on::before { content: ""; display: inline-block; width: 6px; height: 6px; margin-right: 7px; border-radius: 50%; background: var(--accent); vertical-align: 1px; }
#explode { height: 520lvh; }
#explode .sticky .head { will-change: opacity, transform; }
#explode .sticky { position: sticky; top: 0; height: 100lvh; padding: calc(var(--margin) + 56px) var(--margin) var(--margin); }
#explode h2 { font-size: clamp(40px, 6vw, 92px); max-width: 9.5em; }
#explode p { max-width: 20rem; margin-top: .8em; font-weight: 600; font-size: var(--explanation-size); line-height: 1.25; color: var(--fg-3); }

.feature { height: 170lvh; }
.feature .sticky { position: sticky; top: 0; height: 100lvh; display: flex; align-items: flex-end; padding: calc(var(--margin) + 56px) var(--margin) calc(var(--margin) + 8px); }
.feature .copy { max-width: 25rem; opacity: 0; transform: translateY(24px); transition: opacity .6s, transform .6s cubic-bezier(.2,.7,.2,1); }
.feature.is-active .copy { opacity: 1; transform: none; }
.feature :is(h2, h3) { font-size: clamp(44px, 5.4vw, 84px); color: var(--c); margin-bottom: .32em; }
.feature p { font-size: var(--explanation-size); line-height: 1.3; font-weight: 600; color: var(--fg-2); }
.feature ul b { color: var(--fg-1); font-weight: 500; }
.feature ul { list-style: none; margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--fg-4); font-family: var(--mono); font-size: 11.5px; line-height: 1.9; color: var(--fg-3); }
.feature ul li::before { content: ""; display: inline-block; width: 6px; height: 6px; margin-right: 10px; border-radius: 50%; background: var(--c); vertical-align: 1px; }
@media (max-width: 819px) {
  .feature .sticky { align-items: flex-start; }
  .feature .copy { padding: 14px 16px; border-radius: 14px; background: var(--chip); backdrop-filter: blur(10px); }
}

#parts .section-inner { padding-top: calc(var(--margin) + 80px); padding-bottom: 80px; }
#parts .wrap { margin-left: auto; width: min(640px, 100%); }
#parts h2 { font-size: clamp(40px, 5vw, 76px); }
#parts p.lead { margin-top: .7em; font-weight: 600; font-size: var(--explanation-size); color: var(--fg-2); max-width: 30rem; }
.parts-list { margin-top: 28px; display: grid; grid-template-columns: 1fr 1fr; gap: 1px; border-radius: 12px; overflow: hidden; background: #2c2a28; }
.parts-list li { list-style: none; padding: 14px 16px 14px 34px; position: relative; background: rgba(18, 18, 19, .86); backdrop-filter: blur(8px); transition: background .2s; cursor: default; }
.parts-list li:hover { background: rgba(38, 36, 34, .92); }
.parts-list li::before { content: ""; position: absolute; left: 14px; top: 19px; width: 8px; height: 8px; border-radius: 50%; background: var(--c); }
.parts-list b { display: block; font-size: 15px; font-weight: 700; }
.parts-list span { display: block; margin-top: 2px; font-family: var(--mono); font-size: 10.5px; color: var(--fg-3); }
.parts-list em { position: absolute; right: 14px; top: 15px; font-style: normal; font-family: var(--mono); font-size: 11px; color: var(--fg-3); }
@media (max-width: 600px) { .parts-list { grid-template-columns: 1fr; } }


/* ---------- photographs (between the 3D chapters: opaque, the canvas waits behind) ---------- */
.photo { position: relative; z-index: 5; background: #000; pointer-events: auto; }
.photo-full { height: 100svh; min-height: 560px; overflow: hidden; }
.photo-full img { width: 100%; height: 100%; object-fit: cover; }
.photo-full::after { content: ''; position: absolute; inset: 0; background: linear-gradient( to top, rgba( 0, 0, 0, 0.75 ), transparent 45% ); }
.photo-full figcaption { position: absolute; z-index: 1; left: var(--margin); bottom: var(--margin); max-width: 36rem; }
.photo-full figcaption b { display: block; font-weight: 600; font-stretch: 110%; font-size: clamp( 30px, 3.6vw, 56px ); letter-spacing: -0.025em; line-height: 1; }
.photo-full figcaption span { display: block; margin-top: 12px; color: var(--fg-2); font-size: 17px; line-height: 1.4; }
.photo-full .photo-specs { margin-top: 20px; color: var(--accent); font-family: var(--mono); font-size: 13px; line-height: 1.6; }
.feature .copy { max-width: min(29rem, 42vw); }
.feature :is(h2, h3) { font-size: clamp(36px, 4.4vw, 64px); }
.feature .cta { margin-top: 20px; }
@media (max-width: 819px) {
  .feature .copy { max-width: 100%; }
  .feature :is(h2, h3) { font-size: clamp(32px, 6vw, 46px); }
  .feature p { font-size: 18px; }
  .feature .copy { background: transparent; backdrop-filter: none; padding: 0; }
}
.gallery { padding: calc( var(--margin) + 40px ) var(--margin) var(--margin); }
.gallery h2 { font-size: clamp( 36px, 4.4vw, 68px ); margin-bottom: 28px; }
.gallery-grid { display: grid; grid-template-columns: repeat( 12, 1fr ); gap: 10px; }
.gallery-grid figure { position: relative; overflow: hidden; border-radius: 4px; background: #111; }
.gallery-grid img, .gallery-grid video { display: block; width: 100%; height: 100%; object-fit: cover; transition: transform 1.2s cubic-bezier( 0.2, 0.8, 0.2, 1 ); }
.gallery-grid figure:hover img { transform: scale( 1.03 ); }
/* Square photographs set each row's height; the videos fill the wide tiles. */
.g-a { grid-column: span 7; }
.g-b { grid-column: span 5; aspect-ratio: 1; }
.g-c { grid-column: span 5; aspect-ratio: 1; }
.g-c img { object-position: center 67%; }
.g-d { grid-column: span 7; }
.m-cta { margin-top: 40px; display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.m-credit { margin-top: 26px; font-family: var(--mono); font-size: 11px; color: var(--fg-3); }
@media ( max-width: 760px ) {
	.g-a, .g-b, .g-c, .g-d { grid-column: span 12; }
	.g-a, .g-d { aspect-ratio: 16 / 9; }
}

/* ---------- link cards: a small photo and a line (Perception -> Seaker) ---------- */
.peek {
  display: grid; grid-template-columns: 96px 1fr auto; align-items: center; gap: 14px; max-width: 360px; margin-top: 24px; padding: 7px 16px 7px 7px;
  border: 1px solid rgba(246, 244, 242, .18); border-radius: 6px; background: rgba(20, 20, 22, .6); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  color: var(--fg-1); text-decoration: none; transition: border-color .25s, background .25s;
}
.peek img { width: 96px; height: 64px; object-fit: cover; border-radius: 3px; }
.peek-t { display: grid; gap: 4px; }
.peek-t b { font-size: 16px; font-weight: 600; font-stretch: 108%; }
.peek-t small { font-family: var(--mono); font-size: 10.5px; letter-spacing: .06em; text-transform: uppercase; color: var(--fg-3); }
.peek-a { color: var(--accent); transition: transform .25s; }
.peek:hover, .peek:focus-visible { border-color: rgba(246, 244, 242, .45); background: rgba(30, 30, 32, .75); }
.peek:hover .peek-a, .peek:focus-visible .peek-a { transform: translateX(4px); }
.feature:not(.is-active) .copy a { pointer-events: none; }   /* (a faded-out chapter's link is not clickable) */

/* ---------- Discover Seaker (the last section) ---------- */
.next { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr); gap: 40px 56px; align-items: center; min-height: 100svh; padding: calc(var(--margin) + 56px) var(--margin) var(--margin); border-top: 1px solid rgba(246, 244, 242, .12); }
.next h2 { font-size: clamp(40px, 5.4vw, 88px); }
.next .lead { margin-top: 22px; max-width: 30rem; font-size: var(--explanation-size); line-height: 1.45; color: var(--fg-2); }
.next .cta { margin-top: 32px; }
.next-photo { display: block; aspect-ratio: 4 / 3; overflow: hidden; border-radius: 4px; background: #3f4e5c; }
.next-photo img { width: 100%; height: 100%; object-fit: cover; transition: transform 1.2s cubic-bezier(.2, .8, .2, 1); }
.next-photo:hover img { transform: scale(1.03); }
@media (max-width: 819px) { .next { grid-template-columns: 1fr; align-content: center; } .next-photo { order: -1; } }

/* inside the slides (?embed): no chapter bar, no drag hint, no scroll prompt; the gallery fits one screen */
html.embed #chapters, html.embed #drag-hint, html.embed .no-embed, html.embed .m-cta, html.embed .m-credit { display: none !important; }
html.embed .gallery { height: 100vh; display: flex; flex-direction: column; padding-bottom: calc( var(--margin) + 24px ); }
html.embed .gallery-grid { flex: 1; min-height: 0; grid-template-rows: 1fr 1fr; }
html.embed .gallery-grid figure { aspect-ratio: auto; min-height: 0; }

/* One heading connects the hardware chapters and their software conclusion. */
.inside-heading { position: fixed; z-index: 8; top: calc(var(--margin) + 44px); left: var(--margin); right: var(--margin); text-align: center; pointer-events: none; opacity: 0; transform: translateY(10px); transition: opacity .45s, transform .6s cubic-bezier(.2,.7,.2,1); }
.inside-sequence.is-active .inside-heading { opacity: 1; transform: none; }
.inside-heading h2 { font-size: clamp(34px, 4vw, 56px); line-height: 1.05; }
.feature h3 { font-weight: 640; font-stretch: 112%; letter-spacing: -.035em; line-height: .96; }
#software { height: 240svh; }
@media (max-width: 819px) {
  .inside-heading { top: 80px; }
  .inside-heading h2 { font-size: 32px; }
  .inside-sequence .feature .sticky { padding-top: 140px; }
}

@media(max-width:819px) {
  .section-inner { padding-top:calc(var(--margin) + 56px + var(--safe-top)); }
  .deployment-benefits { top:calc(var(--margin) + 52px + var(--safe-top)); }
  #field .operation-copy { padding-top:calc(100px + var(--safe-top)); }
  .inside-heading { top:calc(80px + var(--safe-top)); }
  .inside-sequence .feature .sticky { padding-top:calc(140px + var(--safe-top)); }
  .operation-caption { bottom:calc(30px + env(safe-area-inset-bottom,0px)); }
}
/* Short landscape windows can scroll the copy rather than clipping it. */
@media(min-width:820px) and (max-height:600px) and (orientation:landscape) {
  #intro h1 { font-size:72px; }
  #chapters { display:none; }
  .inside-heading { top:calc(64px + var(--safe-top)); }
  .inside-heading h2 { font-size:26px; }
  .inside-sequence .feature .sticky { height:auto; min-height:100svh; align-items:flex-start; padding-top:112px; }
  .feature h3 { font-size:32px; }
  .feature p { font-size:18px; }
  .feature ul { font-size:10.5px; }
}