/* SmileVision AI · marketing site
   Dark, cinematic, one design system. Tokens first; components after. */

:root {
  --bg: #04060a;
  --bg-2: #070b12;
  --bg-3: #0b111c;
  --panel: rgba(12, 18, 30, 0.58);
  --panel-solid: #0b111b;
  --line: rgba(255, 255, 255, 0.08);
  --line-2: rgba(255, 255, 255, 0.14);
  --ink: #eef3f8;
  --ink-2: #c3ccd8;
  --muted: #8794a8;
  --faint: #5a6577;

  --amber: #f5a623;
  --coral: #fb6340;
  --gold: #ffc24a;
  --grad: linear-gradient(120deg, #ffd27a 0%, #f5a623 38%, #fb6340 100%);
  --cyan: #5fd8ff;
  --cyan-2: #a6ecff;
  --violet: #a78bfa;
  --green: #34d399;
  --red: #f87171;
  --yellow: #facc15;

  --f-sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --f-mono: "Geist Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --f-serif: "Instrument Serif", "Iowan Old Style", Georgia, serif;

  --gutter: clamp(16px, 4vw, 56px);
  --maxw: 1320px;
  --r-sm: 10px;
  --r: 18px;
  --r-lg: 28px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --nav-h: 72px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; background: var(--bg); -webkit-tap-highlight-color: transparent; }
html.lenis, html.lenis body { height: auto; }
.lenis.lenis-smooth { scroll-behavior: auto !important; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--f-sans);
  font-size: 17px;
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: clip;
  text-rendering: optimizeLegibility;
}
body.is-loading { overflow: hidden; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0; font-weight: 500; }
p { margin: 0; }
::selection { background: rgba(245, 166, 35, 0.35); color: #fff; }
:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; border-radius: 6px; }
.mono { font-family: var(--f-mono); font-size: 11.5px; letter-spacing: 0.12em; text-transform: uppercase; }
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding-left: max(var(--gutter), env(safe-area-inset-left, 0px)); padding-right: max(var(--gutter), env(safe-area-inset-right, 0px)); }
.skip { position: fixed; left: 12px; top: -60px; z-index: 200; background: var(--amber); color: #111; padding: 10px 14px; border-radius: 8px; font-weight: 600; }
.skip:focus { top: 12px; }

/* film grain + vignette over everything */
.grain {
  position: fixed; inset: -50%; z-index: 90; pointer-events: none; opacity: 0.055;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='220' height='220'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1  0 0 0 0 1  0 0 0 0 1  0 0 0 0.9 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  animation: grain 1.2s steps(6) infinite;
}
@keyframes grain { 0% { transform: translate(0, 0); } 20% { transform: translate(-3%, 2%); } 40% { transform: translate(2%, -3%); } 60% { transform: translate(-2%, -1%); } 80% { transform: translate(3%, 3%); } 100% { transform: translate(0, 0); } }

#gl { position: fixed; top: 0; left: 0; width: 100%; height: 100vh; height: 100lvh; z-index: 0; pointer-events: none; transition: opacity 0.2s linear; }
.gl-fallback { position: fixed; inset: 0; z-index: 0; pointer-events: none; display: none;
  background: radial-gradient(60% 50% at 70% 45%, rgba(58, 168, 255, 0.18), transparent 70%), radial-gradient(40% 40% at 72% 55%, rgba(245, 166, 35, 0.12), transparent 70%); }
.no-webgl .gl-fallback { display: block; }
main, .footer { position: relative; z-index: 2; }

/* ───────── buttons, chips ───────── */
.btn {
  --h: 52px;
  position: relative; display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  height: var(--h); padding: 0 26px; border-radius: 999px;
  font-weight: 600; font-size: 15.5px; letter-spacing: -0.005em; white-space: nowrap;
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), background 0.3s, color 0.3s, border-color 0.3s;
  will-change: transform;
}
.btn .arrow { transition: transform 0.4s var(--ease); }
.btn:hover .arrow { transform: translateX(4px); }
.btn-primary { color: #170d02; background: var(--grad); box-shadow: 0 10px 40px -10px rgba(245, 166, 35, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.45); }
.btn-primary:hover { box-shadow: 0 16px 60px -12px rgba(251, 99, 64, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.5); }
.btn-ghost { color: var(--ink); border: 1px solid var(--line-2); background: rgba(255, 255, 255, 0.03); backdrop-filter: blur(10px); }
.btn-ghost:hover { border-color: rgba(255, 255, 255, 0.3); background: rgba(255, 255, 255, 0.06); }
.btn-sm { --h: 40px; padding: 0 18px; font-size: 14px; }
.btn-lg { --h: 64px; padding: 0 36px; font-size: 18px; }
.btn-block { width: 100%; }
.beta {
  display: inline-flex; align-items: center; height: 20px; padding: 0 8px; margin-left: 4px; border-radius: 999px; vertical-align: 2px;
  font-family: var(--f-mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; font-weight: 500;
  color: var(--gold); background: rgba(245, 166, 35, 0.12); border: 1px solid rgba(245, 166, 35, 0.32);
}
.glass {
  background: linear-gradient(180deg, rgba(20, 28, 44, 0.62), rgba(10, 15, 25, 0.62));
  border: 1px solid var(--line);
  border-radius: var(--r);
  backdrop-filter: blur(18px) saturate(1.2);
  -webkit-backdrop-filter: blur(18px) saturate(1.2);
  box-shadow: 0 30px 80px -30px rgba(0, 0, 0, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.05);
}
.kicker { display: flex; align-items: center; gap: 12px; font-family: var(--f-mono); font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); margin-bottom: 22px; }
.kicker span { color: var(--amber); }
.kicker::after { content: ""; flex: 0 0 56px; height: 1px; background: linear-gradient(90deg, var(--line-2), transparent); }
h2 { font-size: clamp(36px, 5.2vw, 76px); line-height: 0.98; letter-spacing: -0.04em; font-weight: 500; text-wrap: balance; }
h3 { font-size: clamp(22px, 2vw, 28px); line-height: 1.15; letter-spacing: -0.02em; }
.chapter-lede { color: var(--ink-2); font-size: clamp(16px, 1.25vw, 19px); line-height: 1.6; max-width: 34em; margin-top: 24px; }
.hint { color: var(--muted); margin-top: 28px; }

/* ───────── loader ───────── */
.loader { position: fixed; inset: 0; z-index: 120; display: grid; place-items: center; background: var(--bg); }
.loader-core { width: min(420px, 82vw); text-align: center; }
.loader-smile { width: 120px; height: 40px; margin: 0 auto 18px; overflow: visible; }
.loader-smile path { fill: none; stroke: var(--amber); stroke-width: 5; stroke-linecap: round; stroke-dasharray: 140; stroke-dashoffset: 140; animation: smile 1.4s var(--ease) forwards 0.1s; filter: drop-shadow(0 0 10px rgba(245, 166, 35, 0.6)); }
@keyframes smile { to { stroke-dashoffset: 0; } }
.loader-word { font-weight: 600; letter-spacing: 0.5em; font-size: 15px; margin-left: 0.5em; color: var(--ink); }
.loader-meta { display: flex; justify-content: space-between; margin-top: 36px; font-family: var(--f-mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.loader-pct b { color: var(--ink); font-weight: 500; }
.loader-bar { margin-top: 12px; height: 1px; background: var(--line); overflow: hidden; }
.loader-bar i { display: block; height: 100%; width: 100%; transform-origin: left; transform: scaleX(0); background: linear-gradient(90deg, var(--cyan), var(--amber)); box-shadow: 0 0 12px var(--cyan); }

/* ───────── nav ───────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100; height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  padding: 0 var(--gutter);
  transition: transform 0.5s var(--ease), opacity 0.4s, background 0.4s, border-color 0.4s;
  border-bottom: 1px solid transparent;
  /* iPhone: home-screen web app (status bar) and landscape (notch) */
  height: calc(var(--nav-h) + env(safe-area-inset-top, 0px)); padding-top: env(safe-area-inset-top, 0px);
  padding-left: max(var(--gutter), env(safe-area-inset-left, 0px)); padding-right: max(var(--gutter), env(safe-area-inset-right, 0px));
}
.nav.is-scrolled { background: rgba(4, 6, 10, 0.62); backdrop-filter: blur(18px) saturate(1.3); -webkit-backdrop-filter: blur(18px) saturate(1.3); border-bottom-color: var(--line); }
.nav.is-hidden { transform: translateY(calc(-100% - 48px)); opacity: 0; }   /* clear the Start button's glow too */
.nav-logo img { height: 40px; width: auto; }
.nav-links { display: flex; gap: 34px; font-size: 14.5px; color: var(--ink-2); }
.nav-links a { position: relative; padding: 6px 0; transition: color 0.3s; }
.nav-links a::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1px; background: var(--amber); transform: scaleX(0); transform-origin: right; transition: transform 0.45s var(--ease); }
.nav-links a:hover, .nav-links a.is-active { color: var(--ink); }
.nav-links a:hover::after, .nav-links a.is-active::after { transform: scaleX(1); transform-origin: left; }
.nav-cta { display: flex; align-items: center; gap: 18px; }
.nav-login { font-size: 14.5px; color: var(--ink-2); }
.nav-login:hover { color: var(--ink); }
.nav-burger { display: none; width: 42px; height: 42px; border-radius: 50%; border: 1px solid var(--line-2); background: rgba(255, 255, 255, 0.04); cursor: pointer; position: relative; }
.nav-burger span { position: absolute; left: 13px; right: 13px; height: 1.5px; background: var(--ink); transition: transform 0.4s var(--ease); }
.nav-burger span:first-child { top: 16px; } .nav-burger span:last-child { top: 24px; }
.nav-burger[aria-expanded="true"] span:first-child { transform: translateY(4px) rotate(45deg); }
.nav-burger[aria-expanded="true"] span:last-child { transform: translateY(-4px) rotate(-45deg); }
.nav-sheet { position: fixed; inset: 0; z-index: 99; display: flex; flex-direction: column; justify-content: center; gap: 8px; padding: 0 28px;
  background: rgba(4, 6, 10, 0.94); backdrop-filter: blur(20px); opacity: 0; pointer-events: none; transition: opacity 0.4s var(--ease); }
.nav-sheet a { font-size: 34px; letter-spacing: -0.03em; padding: 8px 0; border-bottom: 1px solid var(--line); }
.nav-sheet.is-open { opacity: 1; pointer-events: auto; }

/* ───────── hero ───────── */
.hero { position: relative; min-height: 100vh; min-height: 100svh; display: flex; flex-direction: column; justify-content: center; padding-top: var(--nav-h); }
.hero-inner { position: relative; z-index: 2; }
.hero-scrim { display: none; }
.hero-title { margin: 0; font-size: clamp(50px, 8.6vw, 136px); line-height: 0.9; letter-spacing: -0.055em; font-weight: 500; max-width: 9.5em; }
.hero-title .line { display: block; overflow: hidden; padding-bottom: 0.06em; }
.hero-title .li { display: inline-block; will-change: transform; }
.hero-title em, h2 em, .final-title em, .manifesto-text em { font-family: var(--f-serif); font-style: italic; font-weight: 400; letter-spacing: -0.02em;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; padding-right: 0.06em; }
.hero-lede { margin-top: 30px; max-width: 34em; font-size: clamp(16.5px, 1.35vw, 20px); color: var(--ink-2); line-height: 1.55; }
.hero-ctas { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 38px; }
.hero-micro { margin-top: 18px; font-family: var(--f-mono); font-size: 11.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.hero-hud { position: absolute; left: 0; right: 0; bottom: 28px; display: flex; justify-content: space-between; align-items: flex-end; z-index: 2; pointer-events: none; }
.scroll-cue { display: flex; align-items: center; gap: 14px; font-family: var(--f-mono); font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); }
.scroll-line { position: relative; width: 1px; height: 46px; background: var(--line-2); overflow: hidden; }
.scroll-line::after { content: ""; position: absolute; left: 0; top: -40%; width: 1px; height: 40%; background: var(--cyan); animation: drip 2s var(--ease) infinite; }
@keyframes drip { to { top: 110%; } }
.specimen { display: flex; flex-direction: column; align-items: flex-end; gap: 4px; color: var(--muted); font-size: 10.5px; }
.specimen span:last-child { color: var(--cyan-2); }

/* 3D HUD labels */
.hud-labels { position: fixed; inset: 0; z-index: 1; pointer-events: none; opacity: 0; }
.hud-lines { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.hud-lines line { stroke: rgba(166, 236, 255, 0.55); stroke-width: 1; }
.hud-lines circle { fill: #a6ecff; }
.hud-label { position: absolute; left: 0; top: 0; display: grid; grid-template-columns: auto auto; column-gap: 8px; align-items: center; padding: 8px 12px 8px 10px; border-radius: 10px;
  background: rgba(6, 12, 22, 0.66); border: 1px solid rgba(166, 236, 255, 0.22); backdrop-filter: blur(8px); white-space: nowrap; will-change: transform; }
.hud-label i { grid-row: span 2; width: 8px; height: 8px; border-radius: 50%; background: var(--c); box-shadow: 0 0 10px var(--c); }
.hud-label b { font-size: 13px; font-weight: 600; letter-spacing: -0.01em; }
.hud-label span { font-family: var(--f-mono); font-size: 9.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--cyan-2); }

/* ───────── manifesto + stats ───────── */
.manifesto { padding-top: 18vh; padding-bottom: 14vh; }
.manifesto-text { font-size: clamp(28px, 3.9vw, 58px); line-height: 1.12; letter-spacing: -0.035em; font-weight: 450; max-width: 21em; }
.manifesto-text .w { opacity: 0.14; transition: none; }
.stats { margin-top: 12vh; display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.stat { padding: 34px 28px 0 0; border-right: 1px solid var(--line); }
.stat + .stat { padding-left: 28px; }
.stat:last-child { border-right: 0; }
.stat b { display: block; font-size: clamp(40px, 4.6vw, 68px); font-weight: 500; letter-spacing: -0.05em; line-height: 1; background: linear-gradient(180deg, #fff, #9aa7b8); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { display: block; margin-top: 14px; color: var(--muted); font-size: 14px; line-height: 1.45; max-width: 16em; }

/* ───────── chapters shared ───────── */
.chapter { position: relative; }
.chapter-grid { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.55fr); gap: clamp(28px, 4vw, 64px); align-items: center; min-height: 100vh; padding-top: calc(var(--nav-h) + 3vh); padding-bottom: 4vh; }
.stage { position: relative; margin: 0; }
.hud-frame { padding: 14px; border-radius: var(--r-lg); background: linear-gradient(180deg, rgba(14, 20, 32, 0.8), rgba(6, 9, 15, 0.8)); border: 1px solid var(--line);
  box-shadow: 0 40px 120px -40px rgba(0, 0, 0, 0.9), inset 0 1px 0 rgba(255, 255, 255, 0.04); }
.hud-frame::before, .hud-frame::after { content: ""; position: absolute; width: 22px; height: 22px; border: 1.5px solid rgba(166, 236, 255, 0.55); pointer-events: none; }
.hud-frame::before { left: -1px; top: -1px; border-right: 0; border-bottom: 0; border-top-left-radius: var(--r-lg); }
.hud-frame::after { right: -1px; bottom: -1px; border-left: 0; border-top: 0; border-bottom-right-radius: var(--r-lg); }
.stage-bar { display: flex; justify-content: space-between; gap: 12px; padding: 2px 6px 12px; color: var(--muted); font-size: 10.5px; }
.stage-bar span:last-child { color: var(--cyan-2); }
.stage-media { position: relative; border-radius: 14px; overflow: hidden; background: #000; isolation: isolate; }
.stage-media img { width: 100%; height: auto; }
.overlay { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.stage-cap { margin-top: 12px; padding: 0 6px; color: var(--faint); font-size: 12.5px; line-height: 1.5; }

/* OPG */
.chapter-opg .stage-col { position: relative; }
.chapter-opg .stage-media img { filter: contrast(1.08) brightness(0.98); }
.legend { list-style: none; padding: 0; margin: 30px 0 0; display: flex; flex-wrap: wrap; gap: 8px; max-width: 30em; }
.legend li { display: inline-flex; align-items: center; gap: 8px; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line); background: rgba(255, 255, 255, 0.02); font-size: 13px; color: var(--ink-2); }
.legend i { width: 8px; height: 8px; border-radius: 2px; background: var(--c); box-shadow: 0 0 8px var(--c); }
.beam { position: absolute; top: 0; bottom: 0; left: 0; width: 2px; background: var(--cyan-2); box-shadow: 0 0 18px 4px rgba(95, 216, 255, 0.75), 0 0 80px 20px rgba(95, 216, 255, 0.25); opacity: 0; pointer-events: none; }
.beam::before { content: ""; position: absolute; top: 0; bottom: 0; right: 2px; width: 140px; background: linear-gradient(90deg, transparent, rgba(95, 216, 255, 0.16)); }
.beam.amber { background: #ffe0a3; box-shadow: 0 0 18px 4px rgba(245, 166, 35, 0.75), 0 0 80px 20px rgba(245, 166, 35, 0.25); }
.beam.amber::before { background: linear-gradient(90deg, transparent, rgba(245, 166, 35, 0.16)); }
.tooth-tag rect { fill: rgba(6, 12, 22, 0.78); stroke: rgba(166, 236, 255, 0.45); stroke-width: 1.5; }
.tooth-tag text { fill: #e9f8ff; font-family: var(--f-mono); font-size: 22px; font-weight: 500; text-anchor: middle; dominant-baseline: central; }
.tooth-box { fill: none; stroke: rgba(166, 236, 255, 0.16); stroke-width: 1.5; }
.find-box { fill: none; stroke-width: 3; }
.find-fill { opacity: 0.12; }
.find-label rect { stroke: none; }
.find-label text { font-family: var(--f-sans); font-weight: 600; font-size: 25px; dominant-baseline: central; fill: #0a0d12; }
.opg-layout { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; gap: clamp(20px, 3.4vh, 40px); padding-top: calc(var(--nav-h) + 1vh); padding-bottom: 3vh; }
.opg-head { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr); gap: clamp(24px, 4vw, 64px); align-items: end; }
.opg-head h2 { font-size: clamp(36px, 4.3vw, 66px); }
.opg-head .chapter-lede { margin-top: 0; font-size: clamp(15px, 1.1vw, 17px); }
.opg-head .legend { margin-top: 16px; }
.opg-head .legend li { padding: 4px 10px; font-size: 12px; }
.opg-body { display: grid; grid-template-columns: minmax(0, 1fr) 290px; gap: 20px; align-items: stretch; }
.opg-panel { padding: 18px; display: flex; flex-direction: column; }
.opg-panel .odonto { margin-top: 12px; }
.teeth-sum { margin-top: auto; display: flex; align-items: center; gap: 12px; padding-top: 12px; border-top: 1px solid var(--line); }
.teeth-sum b { font-size: 34px; font-weight: 500; letter-spacing: -0.04em; line-height: 1; color: var(--cyan-2); }
.teeth-sum span { font-size: 12px; color: var(--muted); line-height: 1.35; }
.panel-head { display: flex; justify-content: space-between; align-items: center; color: var(--muted); font-size: 10.5px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.panel-head b { font-family: var(--f-sans); font-size: 22px; letter-spacing: -0.02em; color: var(--ink); font-weight: 600; }
.panel-head .tag { color: var(--green); }
.panel-list { list-style: none; margin: 10px 0 14px; padding: 0; }
.panel-list li { display: flex; align-items: center; gap: 10px; padding: 7px 0; font-size: 13.5px; color: var(--ink-2); border-bottom: 1px dashed rgba(255, 255, 255, 0.06); }
.panel-list li i { width: 8px; height: 8px; border-radius: 2px; background: var(--c); box-shadow: 0 0 8px var(--c); flex: none; }
.panel-list li em { margin-left: auto; font-style: normal; font-family: var(--f-mono); font-size: 11px; color: var(--muted); }
.panel-list li b { font-weight: 600; color: var(--ink); min-width: 1.4em; }
.odonto { display: grid; grid-template-columns: repeat(16, 1fr); gap: 3px; }
.odonto span { position: relative; height: 22px; border-radius: 4px; border: 1px solid rgba(255, 255, 255, 0.1); background: rgba(255, 255, 255, 0.02); font-family: var(--f-mono); font-size: 7.5px; color: var(--faint); display: grid; place-items: center; transition: background 0.4s, border-color 0.4s, color 0.4s, box-shadow 0.4s; }
.odonto span.mid { margin-left: 3px; }
.odonto span.seen { border-color: rgba(166, 236, 255, 0.4); color: var(--cyan-2); background: rgba(95, 216, 255, 0.08); }
.odonto span.find { border-color: var(--c, var(--amber)); background: color-mix(in srgb, var(--c, var(--amber)) 22%, transparent); color: #fff; box-shadow: 0 0 10px -2px var(--c, var(--amber)); }
.odonto-key { display: flex; flex-wrap: wrap; gap: 4px 12px; margin-top: 10px; color: var(--faint); font-size: 9px; }
.odonto-key i { display: inline-block; width: 8px; height: 8px; border-radius: 2px; margin-right: 6px; vertical-align: -1px; border: 1px solid rgba(255, 255, 255, 0.2); }
.odonto-key .k-seen { border-color: rgba(166, 236, 255, 0.6); background: rgba(95, 216, 255, 0.15); }
.odonto-key .k-find { border-color: var(--amber); background: rgba(245, 166, 35, 0.35); }
.reticle { position: absolute; left: 0; top: 0; pointer-events: none; opacity: 0; transition: opacity 0.25s; z-index: 4; }
.reticle i { position: absolute; left: -22px; top: -22px; width: 44px; height: 44px; border: 1px solid rgba(166, 236, 255, 0.8); border-radius: 50%; box-shadow: 0 0 20px rgba(95, 216, 255, 0.35); }
.reticle i::before, .reticle i::after { content: ""; position: absolute; background: rgba(166, 236, 255, 0.85); }
.reticle i::before { left: 50%; top: -10px; bottom: -10px; width: 1px; }
.reticle i::after { top: 50%; left: -10px; right: -10px; height: 1px; }
.reticle span { position: absolute; left: 30px; top: 18px; white-space: nowrap; padding: 5px 9px; border-radius: 7px; background: rgba(6, 12, 22, 0.85); border: 1px solid rgba(166, 236, 255, 0.3); color: var(--cyan-2); font-size: 10px; }
.film { position: relative; }
.is-hover .reticle, .is-tap .reticle { opacity: 1; }
.is-hover { cursor: none; }

/* intra-oral */
.chapter-io { padding-top: 16vh; padding-bottom: 16vh; }
.io-grid { display: grid; grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.3fr); gap: clamp(28px, 5vw, 80px); align-items: center; }
.io-box { fill: none; stroke-width: 6; }
.io-label text { font-family: var(--f-sans); font-weight: 600; font-size: 34px; dominant-baseline: central; fill: #0a0d12; }
.lens { position: absolute; width: 190px; height: 190px; border-radius: 50%; pointer-events: none; opacity: 0; transform: translate(-50%, -50%) scale(0.6);
  transition: opacity 0.3s, transform 0.4s var(--ease); background-repeat: no-repeat; border: 1.5px solid rgba(166, 236, 255, 0.85);
  box-shadow: 0 0 0 6px rgba(6, 12, 22, 0.35), 0 20px 50px rgba(0, 0, 0, 0.6), inset 0 0 30px rgba(95, 216, 255, 0.25); z-index: 4; }
.is-hover .lens, .is-tap .lens { opacity: 1; transform: translate(-50%, -50%) scale(1); }

/* smile */
.chapter-smile { padding-top: 16vh; padding-bottom: 16vh; }
.smile-grid { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.85fr); gap: clamp(28px, 5vw, 80px); align-items: center; }
.smile-grid .chapter-copy { order: 2; }
.chapter-note { margin-top: 18px; max-width: 34em; color: var(--muted); font-size: 14px; line-height: 1.55; }
.smile-media { --pos: 50%; aspect-ratio: 640 / 420; cursor: ew-resize; touch-action: pan-y; user-select: none; -webkit-user-select: none; }
.smile-media img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; pointer-events: none; -webkit-user-drag: none; }
.smile-before { position: absolute; inset: 0; clip-path: inset(0 calc(100% - var(--pos)) 0 0); }
.smile-handle { position: absolute; top: 0; bottom: 0; left: var(--pos); width: 0; z-index: 3; pointer-events: none; }
.smile-handle::before { content: ""; position: absolute; top: 0; bottom: 0; left: -0.75px; width: 1.5px;
  background: linear-gradient(180deg, rgba(166, 236, 255, 0), rgba(166, 236, 255, 0.95) 18%, rgba(255, 255, 255, 0.95) 50%, rgba(166, 236, 255, 0.95) 82%, rgba(166, 236, 255, 0));
  box-shadow: 0 0 18px rgba(95, 216, 255, 0.55); }
.smile-handle i { position: absolute; top: 84%; left: 0; width: 46px; height: 46px; margin: -23px 0 0 -23px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(8, 12, 20, 0.55); border: 1.5px solid rgba(166, 236, 255, 0.85); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 0 0 6px rgba(6, 12, 22, 0.3), 0 12px 30px rgba(0, 0, 0, 0.5); transition: transform 0.35s var(--ease); }
.smile-handle svg { width: 20px; height: 20px; fill: none; stroke: var(--cyan-2); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.smile-media.is-drag .smile-handle i { transform: scale(1.12); }
.smile-media:has(.smile-range:focus-visible) .smile-handle i { outline: 2px solid var(--amber); outline-offset: 3px; }
.smile-tag { position: absolute; top: 14px; z-index: 2; padding: 5px 10px; border-radius: 999px; font-size: 10.5px; letter-spacing: 0.12em; text-transform: uppercase;
  background: rgba(4, 6, 10, 0.6); border: 1px solid var(--line-2); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); transition: opacity 0.3s; pointer-events: none; }
.tag-before { left: 14px; color: var(--ink-2); }
.tag-after { right: 14px; color: var(--gold); border-color: rgba(245, 166, 35, 0.35); }
.smile-media.is-after .tag-before, .smile-media.is-before .tag-after { opacity: 0; }
.smile-range { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip-path: inset(50%); border: 0; white-space: nowrap; }
.smile-cases { display: flex; gap: 10px; margin-top: 12px; padding: 0 2px; }
.smile-cases button { flex: 0 0 auto; width: 76px; aspect-ratio: 640 / 420; padding: 0; border-radius: 10px; overflow: hidden; cursor: pointer; background: #000;
  border: 1.5px solid var(--line-2); opacity: 0.55; transition: opacity 0.3s, border-color 0.3s, transform 0.4s var(--ease); }
@media (hover: hover) { .smile-cases button:hover { opacity: 0.85; transform: translateY(-2px); } }
.smile-cases button[aria-pressed="true"] { opacity: 1; border-color: var(--amber); box-shadow: 0 6px 22px -6px rgba(245, 166, 35, 0.55); }
.smile-cases img { width: 100%; height: 100%; object-fit: cover; }

/* crown */
.chapter-crown { padding-top: 10vh; padding-bottom: 16vh; }
.crown-grid { display: grid; grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.3fr); gap: clamp(28px, 5vw, 80px); align-items: center; }
.crown-view { aspect-ratio: 4 / 3; cursor: grab; touch-action: pan-y;
  background: radial-gradient(70% 70% at 50% 42%, rgba(58, 168, 255, 0.12), transparent 70%), linear-gradient(180deg, #0a111c, #05080d); }
.crown-stage.is-drag .crown-view { cursor: grabbing; }
.crown-view canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.crown-view .crown-poster { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; transition: opacity 0.6s; }
.crown-stage.is-ready .crown-poster { opacity: 0; pointer-events: none; }
.crown-steps { display: flex; gap: 8px; margin-top: 12px; padding: 0 2px; flex-wrap: wrap; }
.crown-steps button { display: inline-flex; align-items: center; gap: 8px; height: 34px; padding: 0 14px; border-radius: 999px; cursor: pointer;
  font: 500 13px var(--f-sans); color: var(--muted); background: rgba(255, 255, 255, 0.03); border: 1px solid var(--line-2); transition: color 0.3s, border-color 0.3s, background 0.3s; }
.crown-steps button b { font-size: 10.5px; font-weight: 500; color: var(--faint); transition: color 0.3s; }
@media (hover: hover) { .crown-steps button:hover { color: var(--ink); border-color: rgba(255, 255, 255, 0.3); } }
.crown-steps button.is-on { color: var(--ink); border-color: rgba(95, 216, 255, 0.45); background: rgba(95, 216, 255, 0.07); }
.crown-steps button.is-on b { color: var(--cyan-2); }
.crown-steps button[aria-pressed="true"] { border-color: var(--amber); }

/* ceph */
.ceph-layout { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; gap: clamp(18px, 3vh, 36px); padding-top: calc(var(--nav-h) + 1vh); padding-bottom: 3vh; }
.ceph-body { display: grid; grid-template-columns: minmax(0, 1fr) 400px; gap: 20px; align-items: stretch; }
.ceph-stage { display: flex; flex-direction: column; }
.ceph-stage .stage-media { width: min(100%, calc((100vh - 360px) * 0.974)); margin: 0 auto; }
.ceph-head .chapter-lede { font-size: clamp(14.5px, 1vw, 16px); }
.ceph-stage .stage-media img { filter: contrast(1.05); }
.accuracy { display: flex; align-items: center; gap: 16px; margin-top: 18px; padding: 14px 18px; max-width: 34em; }
.acc-num { font-size: 40px; line-height: 1; letter-spacing: -0.05em; font-weight: 500; white-space: nowrap; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.acc-num small { font-size: 18px; margin-left: 3px; letter-spacing: 0; }
.accuracy p { color: var(--ink-2); font-size: 12.5px; line-height: 1.45; }
.accuracy strong { color: var(--ink); font-weight: 600; }
.ceph-panel { padding: 18px; }
.big-angles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 14px 0; }
.angle { min-width: 0; padding: 10px 10px; border-radius: 12px; border: 1px solid var(--line); background: rgba(255, 255, 255, 0.02); }
.angle span { display: block; font-family: var(--f-mono); font-size: 10px; letter-spacing: 0.12em; color: var(--muted); }
.angle b { display: block; margin-top: 4px; font-size: 22px; letter-spacing: -0.03em; font-weight: 600; }
.angle em { display: inline-block; margin-top: 6px; font-style: normal; font-family: var(--f-mono); font-size: 9px; letter-spacing: 0.1em; text-transform: uppercase; padding: 2px 6px; border-radius: 6px; }
.g-normal { color: #86efac; background: rgba(52, 211, 153, 0.12); }
.g-consider { color: #fcd34d; background: rgba(250, 204, 21, 0.12); }
.g-correction { color: #fca5a5; background: rgba(248, 113, 113, 0.14); }
.g-info { color: var(--muted); background: rgba(255, 255, 255, 0.05); }
.ceph-table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.ceph-table th { text-align: left; font-family: var(--f-mono); font-weight: 400; font-size: 9.5px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--faint); padding: 6px 0; border-bottom: 1px solid var(--line); }
.ceph-table td { padding: 5px 0; border-bottom: 1px dashed rgba(255, 255, 255, 0.06); color: var(--ink-2); }
.ceph-table td:nth-child(2) { font-weight: 600; color: var(--ink); white-space: nowrap; }
.ceph-table td:nth-child(2) i { display: inline-block; width: 6px; height: 6px; border-radius: 50%; margin-right: 6px; vertical-align: 1px; }
.ceph-table td:last-child { color: var(--faint); font-family: var(--f-mono); font-size: 10.5px; white-space: nowrap; }
.ceph-verdict { margin-top: 14px; padding: 12px 14px; border-radius: 12px; background: rgba(248, 113, 113, 0.08); border: 1px solid rgba(248, 113, 113, 0.25); font-size: 13.5px; }
.ceph-verdict b { display: block; color: #fecaca; }
.ceph-verdict span { color: var(--muted); font-size: 12px; }
.panel-foot { margin-top: 14px; color: var(--faint); font-size: 9.5px; line-height: 1.6; }
.lm circle.core { fill: #fff; }
.lm circle.halo { fill: rgba(95, 216, 255, 0.22); stroke: rgba(166, 236, 255, 0.95); stroke-width: 3; }
.lm text { font-family: var(--f-mono); font-size: 25px; fill: var(--cyan-2); paint-order: stroke; stroke: rgba(0, 0, 0, 0.75); stroke-width: 4px; }
.trace { fill: none; stroke-linecap: round; stroke-linejoin: round; }
.trace { filter: drop-shadow(0 0 6px rgba(95, 216, 255, 0.45)); }
.trace.t-ref { stroke: rgba(166, 236, 255, 0.95); stroke-width: 4.5; }
.trace.t-plane { stroke: rgba(255, 194, 74, 0.95); stroke-width: 4.5; }
.trace.t-soft { stroke: rgba(196, 181, 253, 0.95); stroke-width: 4.5; }
.trace.t-tooth { stroke: rgba(255, 255, 255, 0.98); stroke-width: 6; }
.arc { fill: none; stroke-width: 4.5; }
.arc-label { font-family: var(--f-mono); font-size: 30px; font-weight: 500; paint-order: stroke; stroke: rgba(0, 0, 0, 0.8); stroke-width: 5px; }

/* CBCT */
.chapter-cbct { min-height: 340vh; }
.cbct-steps { position: relative; padding-top: 22vh; }
.cbct-intro { max-width: 30em; margin-bottom: 30vh; }
.cbct-step { max-width: 27em; padding: 28px 30px; margin-bottom: 48vh; border-radius: var(--r); border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 20, 32, 0.66), rgba(6, 9, 15, 0.5)); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }
.cbct-step:last-of-type { margin-bottom: 30vh; }
.cbct-step h3 { margin-top: 10px; }
.cbct-step p:not(.step-n) { margin-top: 12px; color: var(--ink-2); font-size: 16px; }
.step-n { color: var(--cyan-2); }
.cbct-cap { max-width: 32em; padding-bottom: 18vh; }

/* studios (horizontal) */
.studios { position: relative; }
.studios-pin { height: 100vh; display: flex; flex-direction: column; justify-content: center; overflow: hidden; }
.studios-head { margin-bottom: 4vh; }
.studios-head .chapter-lede { margin-top: 14px; }
.studios-nav { display: none; }
.studios-track { display: flex; gap: 28px; padding-left: max(var(--gutter), calc((100vw - var(--maxw)) / 2 + var(--gutter))); padding-right: 12vw; width: max-content; will-change: transform; }
.studio-card { flex: 0 0 auto; width: max(300px, min(58vw, 880px, calc((100vh - 330px) * 1.6))); transform-style: preserve-3d; }
.studio-shot { position: relative; aspect-ratio: 16 / 10; border-radius: 18px; overflow: hidden; border: 1px solid var(--line-2); background: var(--bg-3);
  box-shadow: 0 40px 100px -40px rgba(0, 0, 0, 0.95); transition: transform 0.6s var(--ease); }
.studio-shot img { width: 100%; height: 100%; object-fit: cover; object-position: top left; }
.studio-shot::after { content: ""; position: absolute; inset: 0; pointer-events: none; background: linear-gradient(115deg, rgba(255, 255, 255, 0.10) 0%, transparent 32%); mix-blend-mode: screen; }
.studio-meta { display: grid; grid-template-columns: auto 1fr; column-gap: 16px; padding: 18px 4px 0; }
.studio-meta .mono { color: var(--amber); padding-top: 6px; grid-row: span 2; }
.studio-meta p { color: var(--muted); font-size: 14.5px; margin-top: 4px; }

/* flywheel */
.flywheel { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(28px, 5vw, 80px); align-items: center; padding-top: 20vh; padding-bottom: 16vh; }
.proof { margin-top: 32px; padding: 20px 22px; max-width: 30em; }
.proof .mono { color: var(--muted); font-size: 10.5px; }
.proof-row { display: flex; align-items: baseline; gap: 14px; margin-top: 10px; flex-wrap: wrap; }
.proof-row b { font-size: 44px; letter-spacing: -0.05em; font-weight: 500; line-height: 1; color: var(--muted); }
.proof-row b.hl { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.proof-arrow { color: var(--faint); font-size: 22px; }
.proof-row small { color: var(--ink-2); font-size: 14px; }
.proof-note { margin-top: 10px; color: var(--muted); font-size: 13.5px; }
.cycle { position: relative; width: min(100%, 520px); aspect-ratio: 1; margin: 0 auto; container-type: inline-size; }
.cycle-svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.ring-base { fill: none; stroke: var(--line); stroke-width: 1.5; }
.ring-run { fill: none; stroke-width: 2.5; stroke-linecap: round; stroke-dasharray: 1257; stroke-dashoffset: 1257; transform-origin: 260px 260px; transform: rotate(-90deg); filter: drop-shadow(0 0 8px rgba(245, 166, 35, 0.6)); }
.ring-dash { fill: none; stroke: rgba(166, 236, 255, 0.25); stroke-width: 1; stroke-dasharray: 2 10; transform-origin: 260px 260px; animation: spin 40s linear infinite; }
.ring-core { fill: var(--amber); filter: drop-shadow(0 0 10px var(--amber)); }
@keyframes spin { to { transform: rotate(360deg); } }
.cycle-node { position: absolute; left: 50%; top: 50%; width: 150px; margin: -32px 0 0 -75px; text-align: center;
  transform: translate(calc(cos(var(--a)) * 38.5cqw), calc(sin(var(--a)) * 38.5cqw)); }
.cycle-node b { display: inline-block; padding: 8px 14px; border-radius: 999px; font-size: 13.5px; font-weight: 600; background: var(--panel-solid); border: 1px solid var(--line-2); box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5); transition: border-color 0.4s, box-shadow 0.4s, color 0.4s; }
.cycle-node span { display: block; margin-top: 6px; font-size: 11.5px; color: var(--muted); }
.cycle-node.is-on b { border-color: var(--amber); color: #fff; box-shadow: 0 0 0 4px rgba(245, 166, 35, 0.12), 0 10px 30px rgba(0, 0, 0, 0.5); }
.cycle-center { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); text-align: center; width: 180px; }
.cycle-center .mono { color: var(--amber); }
.cycle-center b { display: block; margin-top: 8px; font-size: 15px; font-weight: 500; color: var(--ink-2); }

/* founders */
.founders { padding-top: 14vh; padding-bottom: 14vh; }
.founders-head { max-width: 46em; }
.founder-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(20px, 3vw, 44px); margin-top: 8vh; }
.founder { border-radius: var(--r-lg); border: 1px solid var(--line); background: linear-gradient(180deg, rgba(14, 20, 32, 0.7), rgba(6, 9, 15, 0.7)); overflow: hidden; }
.founder-photo { position: relative; aspect-ratio: 4 / 4.3; overflow: hidden; background: #050608; }
.founder-photo img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 18%; filter: grayscale(1) contrast(1.06); transform: scale(1.04); transition: transform 1.4s var(--ease), filter 0.8s; }
.founder-photo::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, transparent 55%, rgba(4, 6, 10, 0.85) 100%), radial-gradient(120% 80% at 50% 0%, transparent 50%, rgba(4, 6, 10, 0.4)); pointer-events: none; }
.founder:hover .founder-photo img { transform: scale(1.0); }
.founder-photo .scan { position: absolute; left: 0; right: 0; top: 0; height: 2px; background: var(--cyan-2); box-shadow: 0 0 22px 6px rgba(95, 216, 255, 0.5); opacity: 0; z-index: 2; }
.founder:hover .founder-photo .scan { animation: scanline 1.6s var(--ease); }
@keyframes scanline { 0% { top: 0; opacity: 0; } 10% { opacity: 1; } 90% { opacity: 1; } 100% { top: 100%; opacity: 0; } }
.founder-photo .tag { position: absolute; left: 20px; bottom: 18px; z-index: 2; padding: 7px 12px; border-radius: 999px; background: rgba(4, 6, 10, 0.7); border: 1px solid var(--line-2); color: var(--ink); font-size: 10.5px; backdrop-filter: blur(8px); }
.founder-body { padding: 28px clamp(22px, 2.4vw, 34px) 32px; }
.founder-body h3 { font-size: clamp(26px, 2.3vw, 34px); letter-spacing: -0.03em; }
.founder-body .role { margin-top: 6px; color: var(--amber); font-size: 11px; }
.founder-body p:not(.role) { margin-top: 18px; color: var(--ink-2); font-size: 15.5px; line-height: 1.65; }
.founder-links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.founder-links a { padding: 8px 14px; border-radius: 999px; border: 1px solid var(--line-2); font-size: 13.5px; color: var(--ink-2); transition: border-color 0.3s, color 0.3s, background 0.3s; }
.founder-links a:hover { border-color: var(--amber); color: var(--ink); background: rgba(245, 166, 35, 0.06); }

/* pricing */
.pricing { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr); gap: clamp(28px, 5vw, 90px); align-items: center; padding-top: 16vh; padding-bottom: 16vh; }
.price-card { --mx: 50%; --my: 30%; --rx: 0deg; --ry: 0deg; position: relative; padding: clamp(26px, 3vw, 40px); border-radius: var(--r-lg); overflow: hidden;
  background: linear-gradient(160deg, #121a2a 0%, #080c14 60%); border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 60px 140px -50px rgba(245, 166, 35, 0.35), 0 40px 100px -40px rgba(0, 0, 0, 0.9), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  transform: perspective(1200px) rotateX(var(--rx)) rotateY(var(--ry)); transition: transform 0.6s var(--ease); }
.price-card > *:not(.foil) { position: relative; z-index: 1; }
.foil { position: absolute; inset: 0; pointer-events: none; opacity: 0.55; mix-blend-mode: color-dodge;
  background: radial-gradient(40% 35% at var(--mx) var(--my), rgba(255, 210, 122, 0.35), transparent 70%),
              conic-gradient(from 210deg at var(--mx) var(--my), rgba(95, 216, 255, 0.0), rgba(95, 216, 255, 0.18), rgba(167, 139, 250, 0.16), rgba(251, 99, 64, 0.16), rgba(255, 210, 122, 0.2), rgba(95, 216, 255, 0.0)); }
.price-top .mono { color: var(--muted); }
.price { display: flex; align-items: flex-start; gap: 6px; margin-top: 18px; }
.price .cur { font-size: 34px; margin-top: 18px; color: var(--ink-2); }
.price b { font-size: clamp(110px, 12vw, 168px); line-height: 0.82; letter-spacing: -0.07em; font-weight: 500; background: linear-gradient(180deg, #fff 20%, #b9c3d1); -webkit-background-clip: text; background-clip: text; color: transparent; }
.price .per { align-self: flex-end; margin-bottom: 14px; font-family: var(--f-mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); line-height: 1.5; }
.price-list { list-style: none; margin: 28px 0; padding: 0; border-top: 1px solid var(--line); }
.price-list li { position: relative; padding: 13px 0 13px 30px; border-bottom: 1px solid var(--line); color: var(--ink-2); font-size: 15.5px; }
.price-list li::before { content: ""; position: absolute; left: 2px; top: 19px; width: 12px; height: 7px; border-left: 2px solid var(--amber); border-bottom: 2px solid var(--amber); transform: rotate(-45deg); }
.price-fine { margin-top: 16px; color: var(--faint); font-size: 13px; text-align: center; }
.price-fine a { color: var(--ink-2); text-decoration: underline; text-underline-offset: 3px; }

/* FAQ */
.faq { padding-top: 6vh; padding-bottom: 16vh; display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: clamp(28px, 5vw, 80px); }
.faq-title { font-size: clamp(36px, 4.4vw, 64px); }
.faq-list { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 24px 0; font-size: clamp(17px, 1.4vw, 21px); letter-spacing: -0.015em; font-weight: 500; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; flex: none; width: 34px; height: 34px; border-radius: 50%; border: 1px solid var(--line-2); display: grid; place-items: center; font-weight: 300; font-size: 20px; color: var(--ink-2); transition: transform 0.4s var(--ease), border-color 0.3s; }
.faq details[open] summary::after { transform: rotate(45deg); border-color: var(--amber); color: var(--amber); }
.faq details p { padding: 0 52px 26px 0; color: var(--ink-2); line-height: 1.65; }

/* final + footer */
.final { position: relative; min-height: 100vh; min-height: 100svh; display: grid; place-items: center; text-align: center; overflow: hidden; }
.final-inner { display: flex; flex-direction: column; align-items: center; gap: 44px; padding-bottom: 34vh; }
.final-title { font-size: clamp(44px, 7.6vw, 120px); line-height: 0.95; letter-spacing: -0.055em; max-width: 11em; }
.footer { border-top: 1px solid var(--line); background: linear-gradient(180deg, rgba(4, 6, 10, 0.4), #030407 40%); padding-top: 70px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 32px; }
.footer-brand img { height: 52px; width: auto; }
.footer-brand p { margin-top: 18px; color: var(--muted); font-size: 14.5px; max-width: 22em; }
.footer h4 { color: var(--faint); margin-bottom: 14px; font-size: 10.5px; }
.footer-grid a { display: block; padding: 5px 0; color: var(--ink-2); font-size: 14.5px; transition: color 0.3s; }
.footer-grid a:hover { color: var(--amber); }
.footer-credits { margin-top: 60px; padding-top: 28px; padding-bottom: calc(40px + env(safe-area-inset-bottom, 0px)); border-top: 1px solid var(--line); display: grid; gap: 10px; }
.footer-credits p { color: var(--faint); font-size: 12.5px; line-height: 1.6; max-width: 76em; }
.credits summary { cursor: pointer; list-style: none; color: var(--faint); font-size: 10.5px; width: fit-content; }
.credits summary::-webkit-details-marker { display: none; }
.credits summary::after { content: " +"; }
.credits[open] summary::after { content: " −"; }
.credits summary:hover { color: var(--ink-2); }
.credits p { margin-top: 10px; }
.credits ul { margin: 8px 0 0; padding-left: 18px; color: var(--faint); font-size: 12px; line-height: 1.65; max-width: 76em; }
.credits a { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }

/* reveal defaults (JS animates them in) */
.js .reveal-up { opacity: 0; transform: translateY(24px); }
.js .split { opacity: 0; }
.js .split.is-split { opacity: 1; }
.split .sl { display: block; overflow: hidden; padding-bottom: 0.08em; margin-bottom: -0.08em; }

/* ───────── responsive ───────── */
@media (max-height: 820px) and (min-width: 961px) {
  .opg-head .chapter-lede { display: none; }
  .ceph-head .accuracy { margin-top: 0; }
}
@media (max-width: 1180px) {
  .opg-body { grid-template-columns: minmax(0, 1fr); }
  .opg-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
  .opg-panel .panel-head { grid-column: 1 / -1; }
  .opg-panel .panel-list { margin: 0; }
  .ceph-body { grid-template-columns: minmax(0, 1fr) 340px; }
}
@media (max-width: 960px) {
  :root { --nav-h: 64px; }
  .nav-links, .nav-login { display: none; }
  .nav-burger { display: inline-block; }
  .chapter-grid, .io-grid, .smile-grid, .crown-grid, .flywheel, .pricing, .faq, .opg-head { grid-template-columns: minmax(0, 1fr); }
  .smile-grid .chapter-copy { order: 0; }
  .opg-layout { min-height: auto; padding-top: 14vh; }
  .chapter-grid { min-height: auto; padding-top: 14vh; padding-bottom: 8vh; }
  .ceph-layout { min-height: auto; padding-top: 12vh; }
  .ceph-body { grid-template-columns: minmax(0, 1fr); }
  .ceph-stage .stage-media { width: 100%; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat { padding: 26px 18px 26px 0; border-bottom: 1px solid var(--line); }
  .stat + .stat { padding-left: 0; }
  .stat:nth-child(2n) { border-right: 0; padding-left: 18px; }
  .founder-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
  .hero-hud .specimen { display: none; }
  .cbct-step { margin-bottom: 60vh; }
  .cbct-intro { padding: 24px 22px; border-radius: var(--r); border: 1px solid var(--line);
    background: linear-gradient(180deg, rgba(14, 20, 32, 0.72), rgba(6, 9, 15, 0.6)); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }
  .cbct-intro .kicker { margin-bottom: 14px; }
  .cbct-cap { width: fit-content; padding: 10px 14px; border-radius: 12px; background: rgba(4, 6, 10, 0.66); margin-bottom: 8vh; }
  .cbct-step:last-of-type { margin-bottom: 22vh; }
  .chapter-io, .chapter-smile, .chapter-crown { padding-top: 10vh; padding-bottom: 10vh; }
  .hero-title, .final-title, .manifesto-text { filter: drop-shadow(0 2px 18px rgba(4, 6, 10, 0.9)); }
  .studio-card { width: min(78vw, 460px); }
  .cycle-node { width: 112px; margin-left: -56px; margin-top: -18px; }
  .cycle-node span { display: none; }
  .cycle-node b { padding: 6px 10px; font-size: 12px; }
  .cycle-center { width: 130px; }
  .cycle-center b { font-size: 13px; }
}
@media (max-width: 600px) {
  body { font-size: 16px; }
  .hero-scrim { display: block; position: absolute; inset: 0; z-index: 1; pointer-events: none; }
  .hero-scrim i { position: absolute; inset: 0; opacity: 0; transition: opacity 1.4s ease;
    background: linear-gradient(180deg, rgba(4, 6, 10, 0) 0%, rgba(4, 6, 10, 0) 16%, rgba(4, 6, 10, 0.7) 34%, rgba(4, 6, 10, 0.9) 60%, rgba(4, 6, 10, 0.94) 100%); }
  .hero-ready .hero-scrim i { opacity: 1; }
  /* OPG: a wide film you swipe through (the beam pans it during the scan) */
  .chapter-opg .stage-media { overflow-x: auto; overflow-y: hidden; overscroll-behavior-x: contain; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
  .chapter-opg .stage-media::-webkit-scrollbar { display: none; }
  .chapter-opg .film { width: 230%; }
  /* app screens: a native swipe carousel */
  .studios-nav { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 6px 14px; margin: 0 auto 16px; color: var(--muted); font-size: 10.5px; }
  .studios-nav span:nth-child(2) { justify-self: end; }
  .studios-progress { grid-column: 1 / -1; height: 2px; background: var(--line); border-radius: 2px; overflow: hidden; }
  .studios-progress i { display: block; height: 100%; width: 100%; background: var(--grad); transform-origin: left; transform: scaleX(0.11); transition: transform 0.25s; }
  .opg-panel { grid-template-columns: minmax(0, 1fr); }
  .hero { justify-content: flex-end; padding-bottom: 96px; }
  .hero-title { font-size: clamp(46px, 13.5vw, 72px); }
  .hero-ctas .btn { width: 100%; }
  .stats { margin-top: 8vh; }
  .stat b { font-size: 38px; }
  .hud-frame { padding: 8px; border-radius: 18px; }
  .stage-bar { font-size: 9px; }
  .tooth-tag text { font-size: 24px; }
  .smile-handle i { width: 38px; height: 38px; margin: -19px 0 0 -19px; }
  .smile-tag { top: 10px; font-size: 9px; padding: 4px 8px; }
  .tag-before { left: 10px; } .tag-after { right: 10px; }
  .smile-cases button { width: 64px; }
  .crown-steps { gap: 6px; flex-wrap: nowrap; }
  .crown-steps button { height: 32px; padding: 0 10px; gap: 6px; font-size: 12px; }
  .crown-steps button b { font-size: 9.5px; }
  .lm text { display: none; }
  .accuracy { flex-direction: column; align-items: flex-start; }
  .faq details p { padding-right: 0; }
  .studios-pin { height: auto; padding: 14vh 0 10vh; overflow: visible; }
  .studios-track { width: auto; overflow-x: auto; scroll-snap-type: x mandatory; gap: 14px; padding: 0 var(--gutter) 8px; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
  .studios-track::-webkit-scrollbar { display: none; }
  .studio-card { width: auto; flex: 0 0 86%; scroll-snap-align: center; }
  .footer-grid { grid-template-columns: 1fr; }
  .hud-label span { display: none; }
  .hud-label { padding: 6px 10px; }
  .hud-label b { font-size: 11.5px; }
}
@media (prefers-reduced-motion: reduce) {
  .grain, .scroll-line::after, .ring-dash { animation: none !important; }
  .js .reveal-up, .js .split { opacity: 1; transform: none; }
}