/* =========================================================================
   Sapphire Prism Labs — styles.css
   Light "instrument" aesthetic with a dark atmospheric prism hero.
   Hand-authored, no build. One stylesheet for the whole site.
   ========================================================================= */

/* ---- Design tokens ---------------------------------------------------- */
:root {
  /* brand */
  --navy:        #0b1f3a;
  --navy-800:    #0e2647;
  --navy-700:    #13294d;
  --teal:        #14a8a5;
  --teal-bright: #19c8c2;
  --sapphire:    #2f6df0;
  --sapphire-lt: #5b93f5;

  /* surfaces & text (light) */
  --bg:        #eef3f8;
  --bg-2:      #f6f9fc;
  --surface:   #ffffff;
  --ink:       #0b1f3a;
  --muted:     #56657a;
  --faint:     #8a97ac;
  --line:      #e2e9f2;
  --line-2:    #d4deeb;

  /* altitude ramp (mirrors the app's AltitudeZone) */
  --alt-low:     #34c759;
  --alt-medium:  #ffcc00;
  --alt-high:    #ff9500;
  --alt-vhigh:   #ff3b30;
  --alt-extreme: #af52de;
  --alt-ultra:   #5e5ce6;

  /* type */
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
  --font-sans:    -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  --font-mono:    ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  /* scale */
  --container: 1120px;
  --radius:   18px;
  --radius-sm: 12px;
  --radius-lg: 28px;

  --shadow-sm: 0 1px 2px rgba(11,31,58,.05), 0 2px 8px rgba(11,31,58,.05);
  --shadow:    0 6px 24px rgba(11,31,58,.08), 0 2px 6px rgba(11,31,58,.05);
  --shadow-lg: 0 24px 60px rgba(11,31,58,.16), 0 6px 18px rgba(11,31,58,.08);
  --shadow-blue: 0 24px 60px rgba(20,52,120,.45);

  --ease: cubic-bezier(.22,1,.36,1);
}

/* ---- Reset ------------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: none; background: none; }
::selection { background: var(--sapphire); color: #fff; }

/* ---- Layout primitives ------------------------------------------------ */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: 24px; }
.section { padding: clamp(40px, 5.5vw, 80px) 0; }
.section--tight { padding: clamp(28px, 4vw, 52px) 0; }
.section-head { max-width: 60ch; margin-bottom: clamp(20px, 3vw, 36px); }
.section-head.center { margin-inline: auto; text-align: center; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--teal);
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  margin-bottom: 1.1rem;
}
.eyebrow::before {
  content: "";
  width: 22px; height: 1px;
  background: currentColor;
  opacity: .6;
}
.eyebrow.center { justify-content: center; }

h1, h2, h3 { font-family: var(--font-display); font-weight: 700; line-height: 1.05; letter-spacing: -.02em; }
.h-xl { font-size: clamp(2.6rem, 6.5vw, 4.6rem); letter-spacing: -.035em; }
.h-lg { font-size: clamp(2rem, 4.6vw, 3.1rem); letter-spacing: -.03em; }
.h-md { font-size: clamp(1.4rem, 2.6vw, 1.9rem); }
h3    { font-size: 1.2rem; }

.lead { font-size: clamp(1.06rem, 1.6vw, 1.3rem); color: var(--muted); line-height: 1.6; }
.muted { color: var(--muted); }
.mono { font-family: var(--font-mono); }
.nowrap { white-space: nowrap; }
.grad-text {
  background: linear-gradient(100deg, var(--sapphire), var(--teal-bright) 80%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---- Buttons ---------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .55rem;
  font-family: var(--font-sans);
  font-weight: 600; font-size: .95rem;
  padding: .8rem 1.4rem;
  border-radius: 999px;
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), background .2s, color .2s, border-color .2s;
  will-change: transform;
}
.btn:active { transform: translateY(1px) scale(.99); }
.btn--primary { background: var(--navy); color: #fff; box-shadow: var(--shadow-sm); }
.btn--primary:hover { background: #0a2a52; transform: translateY(-2px); box-shadow: var(--shadow); }
.btn--ghost { color: var(--ink); border: 1px solid var(--line-2); background: var(--surface); }
.btn--ghost:hover { border-color: var(--sapphire); color: var(--sapphire); transform: translateY(-2px); }
.btn--lg { padding: 1rem 1.7rem; font-size: 1rem; }

/* on dark backgrounds */
.btn--on-dark.btn--primary { background: #fff; color: var(--navy); }
.btn--on-dark.btn--primary:hover { background: #eaf3ff; }
.btn--on-dark.btn--ghost { background: rgba(255,255,255,.06); color: #e8f1ff; border-color: rgba(255,255,255,.28); }
.btn--on-dark.btn--ghost:hover { border-color: var(--teal-bright); color: #fff; }

/* "coming soon" CTA — looks like an App Store pill, clearly not live */
.btn--soon {
  background: linear-gradient(180deg, #15315c, #0e2342);
  color: #cfe3ff;
  border: 1px solid rgba(255,255,255,.16);
  cursor: default;
}
.btn--soon:hover { transform: none; }
.btn--soon .soon-mark { font-size: 1.3rem; line-height: 0; }
.btn--soon small { display: block; font-size: .66rem; letter-spacing: .14em; text-transform: uppercase; opacity: .7; font-family: var(--font-mono); }
.btn--soon strong { font-weight: 600; font-size: 1rem; letter-spacing: -.01em; }

.arrow-link {
  font-weight: 600; color: var(--sapphire);
  display: inline-flex; align-items: center; gap: .4rem;
}
.arrow-link span { transition: transform .2s var(--ease); }
.arrow-link:hover span { transform: translateX(4px); }

/* ---- Header ----------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, background .3s;
}
.site-header.is-scrolled { border-bottom-color: var(--line); }
/* dark header variant for pages with a dark hero on top */
.site-header.on-dark:not(.is-scrolled) { background: transparent; }
.site-header.on-dark:not(.is-scrolled):not(.nav-is-open) .nav-link,
.site-header.on-dark:not(.is-scrolled):not(.nav-is-open) .brand-text { color: #eaf3ff; }
.site-header.on-dark:not(.is-scrolled):not(.nav-is-open) .nav-toggle span { background: #eaf3ff; }

.nav { display: flex; align-items: center; justify-content: space-between; height: 72px; gap: 1.5rem; }
.brand { display: inline-flex; align-items: center; gap: .6rem; }
.brand-mark { width: 30px; height: 28px; filter: drop-shadow(0 2px 5px rgba(20,52,120,.25)); }
.brand-text { font-family: var(--font-display); font-weight: 700; font-size: 1.04rem; letter-spacing: -.01em; }
.brand-text b { font-weight: 700; }
.brand-text .dim { color: var(--muted); font-weight: 600; }

.nav-menu { display: flex; align-items: center; gap: 2rem; }
.nav-links { display: flex; align-items: center; gap: 1.6rem; list-style: none; padding: 0; margin: 0; }
.nav-link { font-size: .95rem; font-weight: 500; color: var(--muted); transition: color .2s; }
.nav-link:hover { color: var(--ink); }
.site-header.on-dark:not(.is-scrolled):not(.nav-is-open) .nav-link:hover { color: #fff; }

.nav-toggle { display: none; width: 40px; height: 40px; position: relative; }
.nav-toggle span {
  position: absolute; left: 9px; right: 9px; height: 2px; background: var(--ink); border-radius: 2px;
  transition: transform .3s var(--ease), opacity .2s;
}
.nav-toggle span:nth-child(1) { top: 14px; }
.nav-toggle span:nth-child(2) { top: 20px; }
.nav-toggle span:nth-child(3) { top: 26px; }

/* ---- Hero (dark atmospheric) ----------------------------------------- */
.hero {
  position: relative;
  color: #eaf3ff;
  padding: clamp(92px, 12vh, 132px) 0 clamp(48px, 6vw, 80px);
  margin-top: -72px; /* slide under the sticky transparent header */
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(58% 70% at 80% 8%,  rgba(47,109,240,.40), transparent 62%),
    radial-gradient(54% 64% at 92% 96%, rgba(20,168,165,.42), transparent 60%),
    radial-gradient(80% 90% at 12% 26%, rgba(91,147,245,.16), transparent 60%),
    linear-gradient(168deg, #061730 0%, #0b1f3a 52%, #0c3550 100%);
  background-size: 160% 160%, 160% 160%, 160% 160%, 100% 100%;
  animation: heroDrift 22s ease-in-out infinite alternate;
}
@keyframes heroDrift {
  from { background-position: 0% 0%, 100% 100%, 0% 50%, 0 0; }
  to   { background-position: 30% 20%, 70% 80%, 40% 60%, 0 0; }
}
/* grain + faint contour overlay */
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none; opacity: .5;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background: linear-gradient(180deg, transparent 70%, rgba(6,15,30,.45));
}

.hero-inner {
  display: grid; grid-template-columns: 1.08fr .92fr; align-items: center; gap: clamp(2rem, 5vw, 4rem);
}
.hero-copy { max-width: 36ch; }
.hero .eyebrow { color: var(--teal-bright); }
.hero-title { font-size: clamp(2.6rem, 6vw, 4.4rem); letter-spacing: -.035em; line-height: 1.02; }
.hero-sub { margin-top: 1.3rem; font-size: clamp(1.06rem, 1.6vw, 1.28rem); line-height: 1.55; color: #aec6e0; }
.hero-cta { margin-top: 2.2rem; display: flex; flex-wrap: wrap; align-items: center; gap: 1rem; }
.hero-foot { margin-top: 2rem; display: flex; flex-wrap: wrap; gap: 1.4rem; font-family: var(--font-mono); font-size: .74rem; letter-spacing: .04em; color: #7f9bbd; }
.hero-foot span { display: inline-flex; align-items: center; gap: .5rem; }
.hero-foot span::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--teal-bright); box-shadow: 0 0 10px var(--teal-bright); }

.hero-vis { display: flex; align-items: center; justify-content: center; }

/* ---- O2 Ring ---------------------------------------------------------- */
.ring { position: relative; width: clamp(230px, 30vw, 320px); aspect-ratio: 1; }
.ring svg { width: 100%; height: 100%; overflow: visible; transform: rotate(-90deg); }
.ring-track { fill: none; stroke: rgba(255,255,255,.10); }
.ring-arc {
  fill: none; stroke-linecap: round;
  stroke-dasharray: 100;
  stroke-dashoffset: var(--arc-final, 10);
  transition: stroke-dashoffset 1.7s var(--ease);
}
.ring.is-priming .ring-arc { stroke-dashoffset: 100; transition: none; }
.ring--green  .ring-arc { stroke: url(#grad-green); filter: drop-shadow(0 0 10px rgba(52,199,89,.5)); }
.ring--blue   .ring-arc { stroke: url(#grad-blue);  filter: drop-shadow(0 0 12px rgba(47,109,240,.5)); }
/* concentric decorative rings behind */
.ring-halo { position: absolute; inset: -7%; border-radius: 50%; border: 1px solid rgba(255,255,255,.06); }
.ring-halo:nth-child(2) { inset: -16%; opacity: .6; }

.ring-readout {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
}
.ring-num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.8rem, 7vw, 3.8rem);
  letter-spacing: -.04em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.ring-unit { font-family: var(--font-mono); font-size: .78rem; letter-spacing: .14em; color: #9fb6d4; margin-top: .5rem; text-transform: uppercase; }
.ring-band { margin-top: .15rem; font-family: var(--font-mono); font-size: .7rem; letter-spacing: .12em; text-transform: uppercase; }

/* dark-on-light ring (used on app page sections) */
.ring--onlight .ring-track { stroke: rgba(11,31,58,.08); }
.ring--onlight .ring-num { color: var(--ink); }
.ring--onlight .ring-unit { color: var(--faint); }

/* ---- Prism dispersion (studio hero visual) --------------------------- */
.prism-vis { width: clamp(300px, 40vw, 470px); margin-inline: auto; }
.prism-vis svg { width: 100%; height: auto; overflow: visible; }
.ray { opacity: .55; mix-blend-mode: screen; filter: blur(2px); transform-box: fill-box; transform-origin: left center; }
.beam-in { mix-blend-mode: screen; }
.prism-glass { mix-blend-mode: screen; }
.prism-edge { filter: drop-shadow(0 0 7px rgba(160,200,255,.45)); }
.prism-ridge { opacity: .35; }

.js .ray { opacity: 0; animation: rayIn 1.1s var(--ease) forwards; }
.js .ray.r1 { animation-delay: .55s; }
.js .ray.r2 { animation-delay: .68s; }
.js .ray.r3 { animation-delay: .81s; }
.js .ray.r4 { animation-delay: .94s; }
.js .ray.r5 { animation-delay: 1.07s; }
@keyframes rayIn { from { opacity: 0; transform: translateX(-16px) scaleX(.55); } to { opacity: .55; transform: none; } }
.js .beam-in { animation: beamPulse 4.5s ease-in-out infinite; }
@keyframes beamPulse { 0%, 100% { opacity: .82; } 50% { opacity: 1; } }

/* ---- Apps grid -------------------------------------------------------- */
.apps-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.5rem; }
.app-card {
  position: relative; display: flex; flex-direction: column;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.6rem; overflow: hidden;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .25s;
}
a.app-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--line-2); }
.app-card-top { display: flex; align-items: center; gap: 1rem; margin-bottom: 1.1rem; }
.app-icon { width: 64px; height: 64px; border-radius: 16px; box-shadow: var(--shadow-sm); }
.app-name { font-family: var(--font-display); font-weight: 700; font-size: 1.3rem; letter-spacing: -.02em; }
.app-platform { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .12em; text-transform: uppercase; color: var(--teal); margin-top: .15rem; }
.app-desc { color: var(--muted); font-size: .98rem; flex: 1; }
.app-card-foot { margin-top: 1.3rem; display: flex; align-items: center; justify-content: space-between; }
.chip {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase;
  padding: .3rem .6rem; border-radius: 999px; background: rgba(20,168,165,.12); color: #0e8a87;
}
.app-card--soon { background: var(--bg-2); border-style: dashed; }
.app-card--soon .app-icon-ph {
  width: 64px; height: 64px; border-radius: 16px;
  background: repeating-linear-gradient(135deg, var(--line) 0 8px, var(--bg-2) 8px 16px);
  border: 1px solid var(--line-2);
}
.app-card--soon .app-name { color: var(--faint); }

/* ---- Steps (how it works) -------------------------------------------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; counter-reset: step; }
.step { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.7rem; }
.step-num {
  font-family: var(--font-mono); font-size: .8rem; font-weight: 600; letter-spacing: .1em;
  color: var(--sapphire); display: inline-flex; align-items: center; gap: .5rem; margin-bottom: .9rem;
}
.step-num::before { counter-increment: step; content: "0" counter(step); font-size: 1.4rem; font-family: var(--font-display); font-weight: 800; color: var(--ink); }
.step h3 { margin-bottom: .4rem; }
.step p { color: var(--muted); font-size: .96rem; }

/* ---- Altitude → oxygen visual ---------------------------------------- */
.altitude { background: var(--navy); color: #eaf3ff; border-radius: var(--radius-lg); padding: clamp(2rem, 5vw, 3.5rem); position: relative; overflow: hidden; }
.altitude .eyebrow { color: var(--teal-bright); }
.altitude h2 { color: #fff; }
.altitude .lead { color: #aec6e0; }
.alt-ramp {
  position: relative; height: 16px; border-radius: 999px; margin: 2.5rem 0 .8rem;
  background: linear-gradient(90deg,
    var(--alt-low) 0%, var(--alt-medium) 22%, var(--alt-high) 42%,
    var(--alt-vhigh) 62%, var(--alt-extreme) 82%, var(--alt-ultra) 100%);
  box-shadow: 0 0 30px rgba(47,109,240,.25);
}
.alt-ticks { display: flex; justify-content: space-between; font-family: var(--font-mono); font-size: .7rem; color: #8fa8c6; letter-spacing: .04em; }
.alt-bands { display: grid; grid-template-columns: repeat(6, 1fr); gap: .75rem; margin-top: 2.2rem; }
.alt-band { background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius-sm); padding: 1rem .9rem; }
.alt-band .dot { width: 12px; height: 12px; border-radius: 50%; margin-bottom: .7rem; box-shadow: 0 0 12px currentColor; }
.alt-band .name { font-weight: 600; font-size: .92rem; }
.alt-band .range { font-family: var(--font-mono); font-size: .68rem; color: #8fa8c6; margin-top: .15rem; letter-spacing: .02em; }
.alt-band .o2 { font-family: var(--font-display); font-weight: 800; font-size: 1.5rem; margin-top: .7rem; letter-spacing: -.03em; }
.alt-band .o2 small { font-size: .72rem; font-family: var(--font-mono); font-weight: 500; color: #8fa8c6; letter-spacing: .04em; }
.alt-note { margin-top: 1.6rem; font-family: var(--font-mono); font-size: .72rem; color: #7f9bbd; }

/* ---- Features --------------------------------------------------------- */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.4rem 2rem; }
.feature { padding-top: 1.4rem; border-top: 1px solid var(--line-2); }
.feature-ico { width: 26px; height: 26px; color: var(--teal); margin-bottom: .9rem; }
.feature h3 { font-size: 1.08rem; margin-bottom: .35rem; }
.feature p { color: var(--muted); font-size: .95rem; }

/* ---- Watch device frames + screenshots ------------------------------- */
.shots { display: flex; flex-wrap: wrap; gap: clamp(1rem, 3vw, 2.4rem); justify-content: center; }
.shot { text-align: center; }
.watch {
  position: relative; width: 196px; padding: 16px; border-radius: 46px;
  background: linear-gradient(160deg, #2b2f36, #0c0d10);
  box-shadow: var(--shadow-lg), inset 0 1px 1px rgba(255,255,255,.18);
}
.watch::after { /* digital crown */
  content: ""; position: absolute; right: -4px; top: 38%; width: 5px; height: 34px;
  border-radius: 3px; background: linear-gradient(180deg,#3a3f47,#15171b);
}
.watch-screen { border-radius: 34px; overflow: hidden; background: #000; aspect-ratio: 416/496; }
.watch-screen img { width: 100%; height: 100%; object-fit: cover; }
.shot-cap { margin-top: 1rem; font-family: var(--font-mono); font-size: .72rem; letter-spacing: .04em; color: var(--muted); }

/* ---- Callouts --------------------------------------------------------- */
.callouts { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }
.callout { display: flex; gap: 1.1rem; padding: 1.6rem 1.7rem; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--line); }
.callout-ico { flex: none; width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; }
.callout--privacy .callout-ico { background: rgba(20,168,165,.12); color: var(--teal); }
.callout--medical .callout-ico { background: rgba(47,109,240,.1); color: var(--sapphire); }
.callout h3 { font-size: 1.05rem; margin-bottom: .3rem; }
.callout p { color: var(--muted); font-size: .92rem; }

/* ---- CTA band --------------------------------------------------------- */
.cta-band {
  position: relative; overflow: hidden; border-radius: var(--radius-lg); color: #eaf3ff; text-align: center;
  padding: clamp(2.6rem, 6vw, 4.5rem);
  background:
    radial-gradient(60% 120% at 80% 10%, rgba(47,109,240,.5), transparent 60%),
    radial-gradient(60% 120% at 15% 90%, rgba(20,168,165,.45), transparent 60%),
    linear-gradient(160deg, #07203c, #0b1f3a);
}
.cta-band h2 { color: #fff; }
.cta-band p { color: #aec6e0; max-width: 48ch; margin: 1rem auto 2rem; }
.cta-band .hero-cta { justify-content: center; }

/* ---- Footer ----------------------------------------------------------- */
.site-footer { background: var(--navy); color: #b9cae0; padding: clamp(2.4rem, 4.5vw, 3.6rem) 0 1.6rem; }
.footer-top { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 2rem; }
.footer-brand .brand-text { color: #fff; }
.footer-brand p { margin-top: 1rem; font-size: .92rem; color: #8fa8c6; max-width: 32ch; }
.footer-col h4 { font-family: var(--font-mono); font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: #6f88a8; margin-bottom: 1rem; font-weight: 600; }
.footer-col ul { list-style: none; display: grid; gap: .7rem; padding: 0; margin: 0; }
.footer-col a { color: #b9cae0; font-size: .95rem; transition: color .2s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  margin-top: clamp(1.8rem, 3.5vw, 2.8rem); padding-top: 1.4rem; border-top: 1px solid rgba(255,255,255,.08);
  display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; align-items: center;
  font-size: .82rem; color: #7f97b6; font-family: var(--font-mono); letter-spacing: .02em;
}

/* ---- Prose (privacy / support) --------------------------------------- */
.page-head { padding: clamp(104px, 13vh, 144px) 0 clamp(26px, 3.5vw, 44px); background: var(--bg-2); border-bottom: 1px solid var(--line); }
.prose { max-width: 70ch; }
.prose > * + * { margin-top: 1.1rem; }
.prose h2 { font-size: 1.45rem; margin-top: 2.6rem; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.1rem; margin-top: 1.8rem; }
.prose p, .prose li { color: var(--ink); }
.prose ul { padding-left: 1.2rem; display: grid; gap: .5rem; }
.prose strong { font-weight: 650; }
.prose a { color: var(--sapphire); text-decoration: underline; text-underline-offset: 3px; }
.prose .updated { font-family: var(--font-mono); font-size: .8rem; color: var(--faint); letter-spacing: .04em; }
.prose .tldr { background: var(--surface); border: 1px solid var(--line); border-left: 3px solid var(--teal); border-radius: var(--radius-sm); padding: 1.2rem 1.4rem; }

/* ---- FAQ -------------------------------------------------------------- */
.faq { max-width: 760px; display: grid; gap: .8rem; }
.faq-item { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; transition: border-color .2s, box-shadow .2s; }
.faq-item[open] { border-color: var(--line-2); box-shadow: var(--shadow-sm); }
.faq-item summary {
  list-style: none; cursor: pointer; padding: 1.2rem 1.4rem;
  font-family: var(--font-display); font-weight: 600; font-size: 1.05rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-family: var(--font-mono); font-size: 1.4rem; color: var(--teal); transition: transform .25s var(--ease); }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item .faq-body { padding: 0 1.4rem 1.3rem; color: var(--muted); }

/* ---- 404 -------------------------------------------------------------- */
.notfound { min-height: 70vh; display: grid; place-items: center; text-align: center; padding: 4rem 0; }
.notfound .code { font-family: var(--font-mono); font-size: clamp(4rem, 14vw, 8rem); font-weight: 700; letter-spacing: -.04em; color: var(--ink); line-height: .9; }

/* ---- Reveal on scroll ------------------------------------------------- */
/* Only hide-then-reveal when JS is present; no-JS users see everything. */
.reveal { transition: opacity .7s var(--ease), transform .7s var(--ease); }
.js .reveal { opacity: 0; transform: translateY(22px); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal[data-d="1"] { transition-delay: .08s; }
.reveal[data-d="2"] { transition-delay: .16s; }
.reveal[data-d="3"] { transition-delay: .24s; }
.reveal[data-d="4"] { transition-delay: .32s; }

/* hero load-in (only when JS flags it, so no-JS shows content immediately) */
.js .hero .anim { opacity: 0; transform: translateY(16px); animation: fadeUp .8s var(--ease) forwards; }
.hero .anim.d1 { animation-delay: .05s; }
.hero .anim.d2 { animation-delay: .18s; }
.hero .anim.d3 { animation-delay: .32s; }
.hero .anim.d4 { animation-delay: .46s; }
.hero .anim.d5 { animation-delay: .60s; }
@keyframes fadeUp { to { opacity: 1; transform: none; } }

/* ---- Micro-interactions & extra motion ------------------------------- */
/* keyboard focus rings */
:focus-visible { outline: 2px solid var(--sapphire); outline-offset: 3px; }
.site-header.on-dark:not(.is-scrolled) .nav-link:focus-visible,
.hero :focus-visible { outline-color: #8fbcff; }

/* anchor jumps clear the sticky header */
section[id] { scroll-margin-top: 88px; }

/* nav link animated underline */
.nav-link { position: relative; }
.nav-link::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -5px; height: 2px;
  background: currentColor; opacity: .85; border-radius: 2px;
  transform: scaleX(0); transform-origin: left; transition: transform .26s var(--ease);
}
.nav-link:hover::after { transform: scaleX(1); }

/* light sheen sweep on hover */
.btn--primary, .btn--soon { position: relative; overflow: hidden; }
.btn--primary::after, .btn--soon::after {
  content: ""; position: absolute; top: 0; left: -75%; width: 45%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255,255,255,.28), transparent);
  transform: skewX(-18deg); pointer-events: none; transition: left .6s var(--ease);
}
.btn--primary:hover::after, .btn--soon:hover::after { left: 130%; }

/* app card icon flourish */
.app-icon { transition: transform .3s var(--ease); }
a.app-card:hover .app-icon { transform: scale(1.06) rotate(-2.5deg); }

/* prism gentle float */
.js .prism-vis svg { animation: floaty 7.5s ease-in-out infinite; }
@keyframes floaty { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* altitude ramp wipes in when its card is revealed */
.js .altitude .alt-ramp { transform: scaleX(0); transform-origin: left center; transition: transform 1.15s var(--ease) .15s; }
.altitude.is-visible .alt-ramp { transform: scaleX(1); }

/* ---- Ambient: scroll progress · aurora · scroll cue ------------------ */
/* top scroll-progress bar (element created by JS) */
.scroll-progress {
  position: fixed; inset: 0 0 auto 0; height: 3px; z-index: 60;
  background: linear-gradient(90deg, var(--sapphire), var(--teal-bright));
  transform: scaleX(0); transform-origin: left;
  transition: transform .12s ease-out; will-change: transform;
}

/* slow-drifting aurora behind the dark sections */
.altitude, .cta-band, .site-footer { isolation: isolate; }
.site-footer { position: relative; overflow: hidden; }
.altitude > *, .cta-band > *, .site-footer > .container { position: relative; z-index: 1; }
.altitude::before, .cta-band::before, .site-footer::before {
  content: ""; position: absolute; inset: -28%; z-index: 0; pointer-events: none;
  background:
    radial-gradient(38% 48% at 22% 24%, rgba(47,109,240,.42), transparent 62%),
    radial-gradient(42% 52% at 82% 80%, rgba(20,168,165,.38), transparent 62%);
  filter: blur(28px); opacity: .6;
  animation: auroraFloat 20s ease-in-out infinite alternate;
}
.cta-band::before { opacity: .4; }
.site-footer::before { opacity: .42; }
@keyframes auroraFloat {
  0%   { transform: translate3d(-3%, -2%, 0) scale(1); }
  100% { transform: translate3d(4%, 3%, 0) scale(1.12); }
}

/* ---- Responsive ------------------------------------------------------- */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; text-align: left; }
  .hero-copy { max-width: 100%; }
  .hero-vis { order: -1; margin-bottom: 1rem; }
  .steps { grid-template-columns: 1fr; }
  .alt-bands { grid-template-columns: repeat(3, 1fr); }
  .footer-top { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 720px) {
  .nav-menu {
    position: fixed; inset: 72px 0 auto 0;
    background: var(--surface); border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; gap: 0;
    padding: .5rem 24px 1.5rem;
    transform: translateY(-130%); transition: transform .35s var(--ease);
    box-shadow: var(--shadow);
  }
  body.nav-open .nav-menu { transform: translateY(0); }
  .nav-links { flex-direction: column; align-items: stretch; gap: 0; width: 100%; }
  .nav-link { display: block; padding: .95rem .25rem; border-bottom: 1px solid var(--line); color: var(--ink); font-size: 1.05rem; font-weight: 600; }
  .nav-links li:last-child .nav-link { border-bottom: none; }
  .nav-link::after { display: none; }
  .nav-cta { margin-top: 1rem; }
  .nav-cta .btn { width: 100%; }
  .nav-toggle { display: block; }
  body.nav-open .nav-toggle span:nth-child(1) { top: 20px; transform: rotate(45deg); }
  body.nav-open .nav-toggle span:nth-child(2) { opacity: 0; }
  body.nav-open .nav-toggle span:nth-child(3) { top: 20px; transform: rotate(-45deg); }
  /* keep dark-hero header readable once menu opens */
  .site-header.on-dark.nav-is-open { background: var(--bg); }
}
@media (max-width: 560px) {
  .alt-bands { grid-template-columns: 1fr 1fr; }
  .callouts { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr; }
}

/* ---- Reduced motion --------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-delay: 0s !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
  .hero .anim { opacity: 1; transform: none; }
  .ray { opacity: .55; transform: none; }
  .alt-ramp { transform: none !important; }
  .ring-arc { stroke-dashoffset: var(--arc-final, 10); }
}