/* ApiVision — styles
   Tokens first; light is default, dark via prefers-color-scheme. Flat colour, no gradients. */

/* Metric-matched fallback so the swap to Be Vietnam Pro doesn't shift the layout
   (ratios measured against Arial: regular 1.077, semibold 1.024). */
@font-face {
  font-family: "Be Vietnam Pro Fallback";
  src: local("Arial"), local("ArialMT");
  font-weight: 100 500;
  size-adjust: 107.7%;
  ascent-override: 92.9%;
  descent-override: 24.1%;
  line-gap-override: 0%;
}
@font-face {
  font-family: "Be Vietnam Pro Fallback";
  src: local("Arial Bold"), local("Arial-BoldMT");
  font-weight: 600 900;
  size-adjust: 102.4%;
  ascent-override: 97.7%;
  descent-override: 25.4%;
  line-gap-override: 0%;
}

:root {
  --bg: #FFFFFF;
  --bg-alt: #F4F7FA;
  --surface: #FFFFFF;
  --navy: #0B1B33;
  --navy-2: #12284A;
  --text: #0B1B33;
  --text-muted: #4A5A70;
  --border: #DCE3EC;
  --accent: #0B7A75;
  --accent-hover: #086661;
  --accent-on-navy: #3FD1C6;
  --accent-soft: #E3F4F2;

  --on-navy: #EEF3F9;
  --on-navy-muted: #B4C3D6;
  --line-on-navy: rgba(238, 243, 249, .16);

  --badge-dev-fg: #0B6A66;
  --badge-dev-bg: #E3F4F2;
  --badge-research-fg: #3F49A8;
  --badge-research-bg: #ECEEFC;
  --badge-planned-fg: #4A5A70;
  --badge-planned-bg: #EEF2F6;

  --font-sans: "Be Vietnam Pro", "Be Vietnam Pro Fallback", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Menlo, Consolas, monospace;

  --radius: 6px;
  --radius-sm: 3px;
  --shadow: 0 1px 2px rgba(11, 27, 51, .05), 0 6px 18px rgba(11, 27, 51, .05);
  --header-h: 64px;
  --gutter: 16px;
  --maxw: 1160px;
  --ease: cubic-bezier(.2, .7, .2, 1);

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0B1B33;
    --bg-alt: #0F2240;
    --surface: #132A4C;
    --navy: #071325;
    --navy-2: #0E2140;
    --text: #E8EEF5;
    --text-muted: #A9B7C9;
    --border: #22395E;
    --accent: #3FD1C6;
    --accent-hover: #6BDDD4;
    --accent-soft: #123B44;

    --badge-dev-fg: #7FE3DA;
    --badge-dev-bg: #123B44;
    --badge-research-fg: #B9C0FF;
    --badge-research-bg: #22285A;
    --badge-planned-fg: #C2CDDB;
    --badge-planned-bg: #1C3254;

    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 6px 18px rgba(0, 0, 0, .22);
  }
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 8px);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  counter-reset: sec;
}

img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

a { color: var(--accent); text-underline-offset: .2em; }
a:hover { color: var(--accent-hover); }

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}
.band-navy :focus-visible,
.site-header :focus-visible { outline-color: var(--accent-on-navy); }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -100px;
  z-index: 100;
  padding: .6rem 1rem;
  background: var(--accent-on-navy);
  color: var(--navy);
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
}
.skip-link:focus { top: 8px; color: var(--navy); }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.narrow { max-width: 780px; }
.center { text-align: center; }

.display {
  font-weight: 600;
  letter-spacing: -.025em;
  font-size: clamp(1.75rem, 1.3rem + 2vw, 2.75rem);
  line-height: 1.2;
}

/* Section label: "01 —— THE CONTEXT" */
.eyebrow {
  display: flex;
  align-items: center;
  gap: .75rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  font-weight: 500;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}
.eyebrow::before {
  counter-increment: sec;
  content: counter(sec, decimal-leading-zero);
  padding-right: 2.5rem;
  background: linear-gradient(currentColor, currentColor) right center / 1.75rem 1px no-repeat;
}
.center .eyebrow { justify-content: center; }

.lead {
  font-size: clamp(1.0625rem, 1rem + .4vw, 1.25rem);
  line-height: 1.65;
}

.section {
  position: relative;
  padding-block: clamp(4rem, 3rem + 5vw, 7rem);
}
.section-alt { background: var(--bg-alt); }
.section-intro { color: var(--text-muted); margin-top: 1rem; max-width: 60ch; }

.band-navy {
  background: var(--navy);
  color: var(--on-navy);
}
.band-navy .lead { color: var(--on-navy-muted); }

/* ---------- Buttons: squared, clinical ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .6rem;
  min-height: 48px;
  padding: .75rem 1.35rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border: 1.5px solid transparent;
  transition: background-color .2s, color .2s, border-color .2s;
}
.btn-primary {
  background: var(--accent-on-navy);
  color: var(--navy);
}
.btn-primary::after {
  content: "→";
  content: "→" / "";
  transition: transform .25s var(--ease);
}
.btn-primary:hover { background: #6BDDD4; color: var(--navy); }
.btn-primary:hover::after { transform: translateX(4px); }
.btn-ghost {
  color: var(--on-navy);
  border-color: rgba(238, 243, 249, .4);
}
.btn-ghost:hover { border-color: var(--on-navy); color: #FFFFFF; }
.btn-lg { font-size: 1.0625rem; padding: .9rem 1.6rem; word-break: break-all; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 27, 51, .96);
  color: var(--on-navy);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: var(--header-h);
}
.header-inner .brand { margin-right: auto; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  color: inherit;
  text-decoration: none;
}
.brand:hover { color: inherit; }
.brand-mark { color: var(--on-navy); flex: none; }
.brand-dot { fill: var(--accent-on-navy); }
.brand-word {
  font-weight: 500;
  font-size: 1.2rem;
  letter-spacing: -.02em;
}
.brand-word span { font-weight: 700; color: var(--accent-on-navy); }

.lang-switch {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: .3rem .75rem;
  border: 1px solid rgba(238, 243, 249, .3);
  border-radius: var(--radius-sm);
  color: var(--on-navy);
  font-size: .875rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
}
.lang-switch:hover { color: var(--accent-on-navy); border-color: var(--accent-on-navy); }
@media (min-width: 800px) { .lang-switch { order: 3; } }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px; height: 48px;
  margin-right: -10px;
  background: transparent;
  border: 0;
  color: inherit;
  cursor: pointer;
  border-radius: var(--radius-sm);
}
.nav-toggle-bars,
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  display: block;
  width: 22px; height: 2px;
  background: currentColor;
  transition: transform .2s, opacity .2s;
}
.nav-toggle-bars { position: relative; }
.nav-toggle-bars::before,
.nav-toggle-bars::after { content: ""; position: absolute; left: 0; }
.nav-toggle-bars::before { top: -7px; }
.nav-toggle-bars::after { top: 7px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-7px) rotate(-45deg); }

.site-nav a {
  color: var(--on-navy);
  text-decoration: none;
  font-weight: 500;
  font-size: .95rem;
}
.site-nav a:hover { color: var(--accent-on-navy); }

@media (max-width: 799px) {
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: var(--navy);
    border-bottom: 1px solid rgba(255, 255, 255, .08);
  }
  .site-nav:not(.is-open) { display: none; }
  .site-nav ul { padding: .5rem var(--gutter) 1.25rem; }
  .site-nav a {
    display: block;
    padding: .85rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, .08);
  }
  .site-nav li:last-child a { border-bottom: 0; }
}

@media (min-width: 800px) {
  .nav-toggle { display: none; }
  .site-nav ul { display: flex; align-items: center; gap: 1.75rem; }
  .site-nav .nav-cta {
    padding: .45rem .9rem;
    border: 1.5px solid rgba(63, 209, 198, .6);
    border-radius: var(--radius-sm);
    color: var(--accent-on-navy);
  }
  .site-nav .nav-cta:hover { background: rgba(63, 209, 198, .12); }
  .site-nav a[aria-current="true"]:not(.nav-cta) { color: var(--accent-on-navy); }
}

/* ---------- Hero ---------- */
.hero {
  padding-block: clamp(3rem, 2rem + 5vw, 6.5rem);
  /* fine measurement grid, flat colour */
  background-color: var(--navy);
  background-image:
    linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px);
  background-size: 48px 48px;
}
.hero-grid {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}
.hero h1 {
  font-size: clamp(2.25rem, 1.5rem + 3.6vw, 3.75rem);
  font-weight: 600;
  letter-spacing: -.035em;
  line-height: 1.1;
  margin-block: 1.25rem 1.25rem;
  max-width: 16ch;
}
.hero .lead { max-width: 54ch; }

.status-line {
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .02em;
  color: var(--on-navy-muted);
  padding: .4rem .75rem .4rem .6rem;
  border-left: 2px solid var(--accent-on-navy);
  background: rgba(255, 255, 255, .04);
}
.status-dot {
  width: 7px; height: 7px;
  background: var(--accent-on-navy);
  flex: none;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 2rem;
}

.hero-art { max-width: 520px; width: 100%; margin-inline: auto; }
.hero-art svg {
  width: 100%;
  height: auto;
  border: 1px solid #1E3557;
  border-radius: var(--radius);
}
.hero-art text {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: .04em;
}
.hero-art .hud-text text { fill: #8FA9C8; font-size: 9px; }
.hero-art .ann text { fill: #B9CCE2; }
.hero-art .ann path { fill: none; stroke: #8FA9C8; stroke-opacity: .7; stroke-width: 1; }
.hero-art .ann circle { fill: #B9CCE2; }
.hero-art .ann-flag text { fill: #3FD1C6; font-weight: 500; }
.hero-art .ann-flag path { stroke: #3FD1C6; stroke-opacity: 1; }
.hero-art .ann-flag circle { fill: #3FD1C6; }
.hero-art .sweep { opacity: 0; }

@media (min-width: 960px) {
  .hero-grid { grid-template-columns: 1.05fr .95fr; gap: 4rem; }
}

/* ---------- Problem ---------- */
.prose { margin-top: 1.5rem; display: grid; gap: 1.1rem; color: var(--text-muted); font-size: 1.125rem; }
.prose p:last-child { color: var(--text); }

/* ---------- How it works ---------- */
.flow {
  display: grid;
  gap: 1rem;
  margin-top: 2.5rem;
}
.flow-step {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.5rem 1.6rem;
  box-shadow: var(--shadow);
}
.flow-step h3 { font-size: 1.125rem; font-weight: 600; margin-block: .9rem .5rem; letter-spacing: -.01em; }
.flow-step p { color: var(--text-muted); font-size: 1rem; }
.flow-num {
  position: absolute;
  top: 1.25rem; right: 1.25rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  font-weight: 500;
  color: var(--text-muted);
  line-height: 1;
}
.flow-num::before { content: "0"; }
.flow-icon {
  width: 48px; height: 48px;
  fill: none;
  stroke: var(--text);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.flow-icon .fill { fill: var(--accent); stroke: none; }
.flow-icon .accent { stroke: var(--accent); }

.flow-step:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 2.25rem;
  bottom: -1rem;
  width: 2px;
  height: 1rem;
  background: var(--accent);
  opacity: .6;
}
@media (min-width: 960px) {
  .flow { grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }
  .flow-step:not(:last-child)::after {
    left: auto;
    right: -1.5rem;
    top: 3rem;
    bottom: auto;
    width: 1.5rem;
    height: 2px;
  }
}

.flow-caption {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .6rem;
  margin-top: 2rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
}
.flow-caption svg { color: var(--accent); flex: none; }

/* ---------- Tabs ---------- */
.tabs { margin-top: 2.25rem; }
.tab-list {
  display: flex;
  gap: .25rem;
  overflow-x: auto;
  border-bottom: 1px solid var(--border);
  scrollbar-width: none;
}
.tab {
  flex: none;
  min-height: 48px;
  padding: .75rem 1.1rem;
  background: transparent;
  border: 0;
  border-bottom: 3px solid transparent;
  margin-bottom: -1px;
  color: var(--text-muted);
  font: inherit;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
}
.tab:hover { color: var(--text); }
.tab[aria-selected="true"] { color: var(--text); border-bottom-color: var(--accent); }
@media (max-width: 519px) {
  .tab-list { flex-wrap: wrap; overflow: visible; }
  .tab { padding-inline: .75rem; }
}

.tab-panel { padding-top: 1.75rem; }
.tab-panel:focus-visible { outline-offset: 6px; }
.tab-panel[hidden] { display: none; }
.panel-heading { font-size: 1rem; font-weight: 600; color: var(--text-muted); margin-bottom: 1rem; }
/* The tab already names the panel; noscript.css shows these headings instead of tabs */
.panel-heading { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.benefits { display: grid; gap: 1rem; }
.benefits li {
  padding: 1.25rem 1.25rem 1.35rem;
  border-left: 3px solid var(--accent);
  background: var(--bg-alt);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.benefits h4 { font-size: 1.0625rem; font-weight: 600; margin-bottom: .35rem; }
.benefits p { color: var(--text-muted); font-size: 1rem; }
@media (min-width: 760px) {
  .benefits { grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
}
/* panel switch: brief "windowing" fade */
.tab-panel:not([hidden]) .benefits li { animation: window-in .5s var(--ease) both; }
.tab-panel:not([hidden]) .benefits li:nth-child(2) { animation-delay: .06s; }
.tab-panel:not([hidden]) .benefits li:nth-child(3) { animation-delay: .12s; }

/* ---------- Product cards ---------- */
.cards { display: grid; gap: 1.25rem; margin-top: 2.5rem; }
.card {
  display: flex;
  flex-direction: column;
  gap: .75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 3px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}
.card:has(.badge-dev) { border-top-color: var(--badge-dev-fg); }
.card:has(.badge-research) { border-top-color: var(--badge-research-fg); }
.card h3 { font-size: 1.25rem; font-weight: 600; margin-top: .25rem; letter-spacing: -.01em; }
.card p { color: var(--text-muted); font-size: 1rem; }
@media (min-width: 760px) { .cards { grid-template-columns: repeat(3, 1fr); } }

/* Status tags: squared, monospace */
.badge {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .3rem .6rem;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.badge::before {
  content: "";
  width: 6px; height: 6px;
  background: currentColor;
}
.badge-dev { color: var(--badge-dev-fg); background: var(--badge-dev-bg); }
.badge-research { color: var(--badge-research-fg); background: var(--badge-research-bg); }
.badge-planned { color: var(--badge-planned-fg); background: var(--badge-planned-bg); }
.badge-planned::before { background: transparent; border: 1.5px solid currentColor; }

/* ---------- Principles ---------- */
.tiles { display: grid; gap: 1px; margin-top: 2.5rem; background: var(--border); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.tile { background: var(--bg); padding: 1.75rem; }
.tile h3 { font-size: 1.125rem; font-weight: 600; margin-block: 1rem .5rem; letter-spacing: -.01em; }
.tile p { color: var(--text-muted); font-size: 1rem; }
.tile-icon {
  width: 32px; height: 32px;
  fill: none;
  stroke: var(--accent);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
@media (min-width: 640px) { .tiles { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .tiles { grid-template-columns: repeat(4, 1fr); } }

/* ---------- Team ---------- */
.person {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 2rem;
  padding: 1.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.person h3 { font-size: 1.25rem; font-weight: 600; }
.person .role { color: var(--accent); font-weight: 600; margin-block: .2rem .75rem; }
.person p:last-child { color: var(--text-muted); }
.avatar {
  flex: none;
  display: grid;
  place-items: center;
  width: 88px; height: 88px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--accent-on-navy);
  border: 2px solid var(--accent-on-navy);
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: .02em;
}
@media (min-width: 560px) { .person { flex-direction: row; align-items: flex-start; } }

.hiring {
  margin-top: 1.5rem;
  padding-left: 1rem;
  border-left: 3px solid var(--accent);
  color: var(--text);
}

/* ---------- Contact ---------- */
.contact .lead { margin-block: 1rem 2rem; margin-inline: auto; max-width: 52ch; }
.contact-place { margin-top: 1.25rem; color: var(--on-navy-muted); font-size: .95rem; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding-block: 3rem 2rem;
  font-size: .95rem;
}
.site-footer .brand { color: var(--text); }
.site-footer .brand-mark { color: var(--text); }
.site-footer .brand-dot { fill: var(--accent); }
.site-footer .brand-word span { color: var(--accent); }
.footer-grid { display: grid; gap: 2rem; }
.footer-brand p { margin-top: .75rem; color: var(--text-muted); }
.footer-heading {
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: .75rem;
}
.site-footer ul li + li { margin-top: .4rem; }
.site-footer nav a, .site-footer ul a {
  color: var(--text);
  text-decoration: none;
  display: inline-block;
  padding-block: .2rem;
}
.site-footer ul a:hover { color: var(--accent); text-decoration: underline; }
@media (min-width: 720px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }

.footer-legal {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: grid;
  gap: .6rem;
}
.disclaimer { font-size: .875rem; color: var(--text); max-width: 90ch; }
.fineprint { font-size: .8125rem; color: var(--text-muted); }

/* ---------- Viewer HUD (scroll scout + slice counter), wide screens only ---------- */
.viewer-hud { display: none; }
@media (min-width: 1200px) {
  .js .viewer-hud {
    position: fixed;
    right: 20px;
    bottom: 20px;
    z-index: 40;
    display: flex;
    align-items: center;
    gap: .75rem;
    padding: .6rem .75rem .6rem .6rem;
    background: #0B1B33;
    color: #B9CCE2;
    border: 1px solid #1E3557;
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: .6875rem;
    letter-spacing: .06em;
    pointer-events: none;
  }
}
.scout { flex: none; }
.scout-line {
  stroke: #3FD1C6;
  stroke-width: 1.5;
  transform: translateY(calc(6px + var(--p, 0) * 68px));
}
.hud-text { display: grid; gap: .15rem; text-transform: uppercase; min-width: 9.5rem; }
.hud-im { color: #3FD1C6; }

/* ---------- Vietnamese: room for stacked diacritics ---------- */
:lang(vi) .display { line-height: 1.32; }
:lang(vi) .hero h1 { line-height: 1.24; max-width: 20ch; }
:lang(vi) body, :lang(vi) .lead { line-height: 1.75; }

/* =========================================================
   Motion — radiology-inspired, only when motion is welcome
   ========================================================= */
@keyframes window-in {
  /* like adjusting window/level: washed out → crisp */
  from { opacity: 0; filter: contrast(.3) brightness(1.5); }
  to   { opacity: 1; filter: none; }
}

@media (prefers-reduced-motion: no-preference) {

  /* Hero: anatomy traces itself, then labels, ROI, and one scan sweep */
  .hero-art .dr {
    stroke-dasharray: 1 1;
    stroke-dashoffset: 1;
    animation: draw 1.5s cubic-bezier(.6, 0, .2, 1) forwards;
    animation-delay: var(--d, 0s);
  }
  .hero-art .soft     { --d: .1s; }
  .hero-art .airway   { --d: .3s; }
  .hero-art .lungs    { --d: .45s; }
  .hero-art .medi     { --d: .8s; }
  .hero-art .fissures { --d: 1.05s; }
  .hero-art .ribs     { --d: 1.2s; }
  .hero-art .spine    { animation: fade-in .8s ease .9s both; }
  .hero-art .ann      { animation: fade-in .6s ease both; }
  .hero-art .ann:nth-child(1) { animation-delay: 1.7s; }
  .hero-art .ann:nth-child(2) { animation-delay: 1.8s; }
  .hero-art .ann:nth-child(3) { animation-delay: 1.9s; }
  .hero-art .ann:nth-child(4) { animation-delay: 2.0s; }
  .hero-art .ann:nth-child(5) { animation-delay: 2.1s; }
  .hero-art .ann:nth-child(6) { animation-delay: 2.2s; }
  .hero-art .ann-flag         { animation-delay: 2.7s; }
  .hero-art .roi {
    transform-box: fill-box;
    transform-origin: center;
    animation: roi-in .5s var(--ease) 2.5s both;
  }
  .hero-art .sweep { animation: sweep 2.2s cubic-bezier(.45, 0, .55, 1) 1.4s both; }
  .hero-art .hud-text { animation: fade-in .6s ease .2s both; }

  /* Scroll reveal: scan-wipe top→bottom with a window/level settle.
     Pending elements are only transparent (a clip-path here would stop
     IntersectionObserver from ever seeing them). */
  .reveal-pending { opacity: 0; }
  .reveal-pending.is-visible {
    opacity: 1;
    animation:
      scan-wipe .9s var(--ease) calc(var(--i, 0) * 90ms) both,
      window-in 1.1s ease calc(var(--i, 0) * 90ms) both;
  }

  /* Scene change: a scan line crosses the top of each section as it enters */
  .section::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: var(--accent);
    transform: scaleX(0);
    transform-origin: left;
    opacity: 0;
    pointer-events: none;
  }
  .section.in-view::before { animation: scene-scan 1.4s var(--ease) both; }
  .band-navy.section::before { background: var(--accent-on-navy); }

  .scout-line { transition: transform .15s linear; }
}

@keyframes scan-wipe {
  from { clip-path: inset(-30px -30px 100% -30px); }
  to   { clip-path: inset(-30px -30px -30px -30px); }
}
@keyframes draw    { to { stroke-dashoffset: 0; } }
@keyframes fade-in { from { opacity: 0; } to { opacity: 1; } }
@keyframes roi-in  { from { opacity: 0; transform: scale(1.6); } to { opacity: 1; transform: none; } }
@keyframes sweep {
  0%   { opacity: 0;  transform: translateY(0); }
  8%   { opacity: .9; }
  92%  { opacity: .9; }
  100% { opacity: 0;  transform: translateY(520px); }
}
@keyframes scene-scan {
  0%   { transform: scaleX(0); opacity: 1; }
  60%  { transform: scaleX(1); opacity: 1; }
  100% { transform: scaleX(1); opacity: 0; }
}

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