:root {
  --paper: #fff;
  --surface-soft: #edf3f8;
  --ink: #142238;
  --ink-soft: #44546a;
  --muted: #647084;
  --blue: #225ba6;
  --blue-deep: #173f78;
  --blue-pale: #dce9f7;
  --red: #b53d49;
  --red-deep: #832e35;
  --line: #d7e0e9;
  --line-strong: #aebdcb;
  --success: #176747;
  --success-soft: #e9f6ef;
  --warning: #8b4b12;
  --warning-soft: #fff3df;
  --shadow: 0 18px 50px rgba(20, 34, 56, .09);
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.55; }
button, textarea { font: inherit; }
a { color: inherit; }
.skip-link { position: fixed; z-index: 100; top: 8px; left: 8px; padding: .7rem 1rem; background: var(--ink); color: #fff; transform: translateY(-150%); }
.skip-link:focus { transform: translateY(0); }
:focus-visible { outline: 3px solid #e18a92; outline-offset: 3px; }

.topbar { position: sticky; z-index: 20; top: 0; display: flex; align-items: center; justify-content: space-between; min-height: 72px; padding: .8rem max(1.25rem, calc((100vw - var(--max)) / 2)); border-bottom: 1px solid var(--line); background: rgba(255,255,255,.96); backdrop-filter: blur(12px); }
.brand { font-size: .95rem; font-weight: 900; letter-spacing: .105em; text-decoration: none; white-space: nowrap; }
.brand span { color: var(--red); }
.topbar nav { display: flex; align-items: center; gap: clamp(.75rem, 2vw, 1.6rem); }
.topbar nav a { padding: .5rem .1rem; color: var(--ink-soft); font-size: .91rem; font-weight: 700; text-decoration: none; }
.topbar nav a:hover, .topbar nav a[aria-current="page"] { color: var(--blue-deep); text-decoration: underline; text-underline-offset: .35rem; text-decoration-color: var(--red); }

main > section { width: min(var(--max), calc(100% - 2.5rem)); margin-inline: auto; padding: clamp(4.2rem, 8vw, 7rem) 0; }
.hero { min-height: 0; padding-block: clamp(4.5rem, 9vw, 7.5rem); }
.eyebrow { margin: 0 0 .8rem; color: var(--red-deep); font-size: .77rem; font-weight: 850; letter-spacing: .13em; text-transform: uppercase; }
h1, h2, h3, h4, p { text-wrap: pretty; }
h1 { max-width: 760px; margin: 0; font-size: clamp(2.6rem, 6vw, 5.7rem); line-height: .98; letter-spacing: -.058em; }
h1 span { color: var(--blue); }
.lead { max-width: 680px; margin: 1.6rem 0 0; color: var(--ink-soft); font-size: clamp(1.05rem, 2vw, 1.3rem); }
.hero-actions, .answer-actions { display: flex; flex-wrap: wrap; align-items: center; gap: .8rem; margin-top: 1.8rem; }
.button { display: inline-flex; min-height: 46px; align-items: center; justify-content: center; padding: .78rem 1.12rem; border: 1px solid var(--blue); border-radius: 9px; font-weight: 800; text-decoration: none; cursor: pointer; }
.button-primary { background: var(--blue-deep); color: #fff; }
.button-primary:hover { background: var(--blue); }
.button-secondary { background: #fff; color: var(--blue-deep); }
.button-secondary:hover { background: var(--surface-soft); }
.honesty-note { max-width: 690px; margin: 1.5rem 0 0; padding-left: 1rem; border-left: 3px solid var(--red); color: var(--muted); font-size: .88rem; }
.honesty-note strong { color: var(--ink); }

.section-heading { max-width: 760px; margin-bottom: 2rem; }
.section-heading h2, .final-cta h2 { margin: 0; font-size: clamp(2rem, 4.7vw, 3.7rem); line-height: 1.04; letter-spacing: -.045em; }
.section-heading > p:last-child, .final-cta > p { color: var(--ink-soft); font-size: 1.05rem; }
.demo-section { border-top: 1px solid var(--line); }
.demo-shell { overflow: hidden; border: 1px solid var(--line-strong); border-radius: 20px; background: #fff; box-shadow: var(--shadow); }
.demo-selector { padding: 1.25rem; border-bottom: 1px solid var(--line); background: var(--surface-soft); }
.demo-selector fieldset + fieldset { margin-top: 1rem; }
fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
legend { margin-bottom: .55rem; color: var(--ink-soft); font-size: .78rem; font-weight: 850; letter-spacing: .08em; text-transform: uppercase; }
.choice-row { display: flex; flex-wrap: wrap; gap: .5rem; }
.year-row { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); }
.choice { min-height: 41px; padding: .55rem .8rem; border: 1px solid var(--line-strong); border-radius: 8px; background: #fff; color: var(--ink-soft); font-weight: 750; cursor: pointer; }
.choice:hover { border-color: var(--blue); color: var(--blue-deep); }
.choice.is-selected { border-color: var(--blue-deep); background: var(--blue-deep); color: #fff; }
.learning-stage { padding: clamp(1.25rem, 4vw, 2.5rem); }
.stage-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; padding-bottom: 1.4rem; border-bottom: 1px solid var(--line); }
.stage-path { margin: 0 0 .25rem; color: var(--red-deep); font-size: .78rem; font-weight: 850; letter-spacing: .07em; text-transform: uppercase; }
.stage-header h3 { margin: 0; font-size: clamp(1.35rem, 3vw, 2rem); line-height: 1.15; }
.stage-duration { flex: 0 0 auto; padding: .35rem .55rem; border-radius: 99px; background: var(--blue-pale); color: var(--blue-deep); font-size: .75rem; font-weight: 800; }
.stage-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(300px, .85fr); gap: 1.5rem; padding-top: 1.6rem; }
.challenge, .feedback-panel { min-width: 0; }
.stage-label { margin: 0 0 .55rem; color: var(--muted); font-size: .76rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
.prompt { margin: 0 0 1rem; font-size: 1.12rem; font-weight: 650; }
.representation { display: flex; min-height: 74px; align-items: center; justify-content: center; margin: 1rem 0; padding: 1rem; border: 1px solid var(--line); border-radius: 12px; background: var(--surface-soft); color: var(--blue-deep); font-size: clamp(1.15rem, 3vw, 1.65rem); font-weight: 900; text-align: center; }
.challenge label { display: block; margin: 1.15rem 0 .4rem; font-weight: 800; }
textarea { width: 100%; resize: vertical; padding: .85rem; border: 1px solid var(--line-strong); border-radius: 9px; background: #fff; color: var(--ink); }
textarea:focus { border-color: var(--blue); }
.text-button { min-height: 42px; padding: .5rem .25rem; border: 0; background: transparent; color: var(--blue-deep); font-weight: 800; text-decoration: underline; text-underline-offset: 4px; cursor: pointer; }
.input-hint { margin: .7rem 0 0; color: var(--muted); font-size: .82rem; }
.feedback-panel { padding: 1.25rem; border: 1px solid var(--line); border-radius: 14px; background: #fbfcfd; }
.feedback-panel h4 { margin: 0; font-size: 1.25rem; line-height: 1.2; }
.feedback-panel > p:not(.stage-label) { color: var(--ink-soft); }
.feedback-panel.is-good { border-color: #8dc4ad; background: var(--success-soft); }
.feedback-panel.is-revise { border-color: #e0b67b; background: var(--warning-soft); }
.feedback-panel.is-empty { border-color: #d79ba1; background: #fff1f2; }
.feedback-evidence { margin-top: 1rem; padding: .85rem; border-radius: 9px; background: rgba(255,255,255,.72); font-size: .91rem; }
.feedback-evidence strong { display: block; margin-bottom: .25rem; }
.next-move { margin-top: 1rem; padding-top: 1rem; border-top: 1px solid currentColor; }
.next-move span { color: var(--red-deep); font-size: .74rem; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
.next-move p { margin: .3rem 0 0; font-weight: 700; }

.recording-section { border-top: 1px solid var(--line); }
.product-videos { display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-bottom:clamp(3rem,7vw,5.5rem) }
.product-videos figure { margin:0;overflow:hidden;border:1px solid var(--line-strong);border-radius:16px;background:#fff;box-shadow:var(--shadow) }
.product-videos video { display:block;width:100%;aspect-ratio:16/9;background:#10233a;object-fit:contain }
.product-videos figcaption { display:grid;gap:.2rem;padding:1rem 1.1rem }
.product-videos figcaption strong { color:var(--blue-deep) }
.product-videos figcaption span { color:var(--ink-soft);font-size:.88rem }

.final-cta { margin-bottom: 5rem; border: 1px solid var(--line); border-radius: 20px; background: var(--surface-soft); text-align: center; }
.final-cta > p { max-width: 660px; margin-inline: auto; }
.final-cta > div { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: .8rem; margin-top: 1.5rem; }
.text-link { padding: .7rem; color: var(--blue-deep); font-weight: 800; }
footer { display: grid; grid-template-columns: auto 1fr auto; gap: 1.5rem; align-items: center; padding: 2rem max(1.25rem, calc((100vw - var(--max)) / 2)); border-top: 1px solid var(--line); color: var(--muted); }
footer p { margin: 0; }
footer nav { display: flex; flex-wrap: wrap; gap: 1rem; }
footer nav a { font-size: .85rem; }

@media (max-width: 900px) {
  .stage-grid { grid-template-columns: 1fr; }
  .year-row { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  html, body { max-width: 100%; overflow-x: clip; }
  html { scroll-padding-top: 64px; }
  .topbar { min-height: 62px; padding: .6rem 1rem; }
  .topbar nav { gap: .7rem; }
  .topbar nav a { font-size: .78rem; }
  .topbar nav { gap: .45rem; }
  .topbar nav a { font-size: .7rem; }
  main > section { width: min(100% - 1.5rem, var(--max)); padding: 3.6rem 0; }
  h1 { max-width: 100%; font-size: clamp(2.35rem, 11.8vw, 3.15rem); line-height: 1; overflow-wrap: anywhere; }
  .hero-copy, .lead, .section-heading, .section-heading h2, .honesty-note, .demo-shell, .learning-stage { min-width: 0; max-width: 100%; overflow-wrap: anywhere; }
  .demo-selector { padding: 1rem; }
  .choice-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .year-row { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .year-row .choice:last-child { grid-column: 1 / -1; }
  .stage-header { display: block; }
  .stage-duration { display: inline-block; margin-top: .75rem; }
  .answer-actions { align-items: stretch; }
  .answer-actions > * { width: 100%; }
  .product-videos { grid-template-columns:1fr }
  .final-cta { padding-inline: 1rem; }
  .final-cta .button { width: 100%; }
  footer { grid-template-columns: 1fr; }
}

@media (max-width: 430px) {
  .topbar nav a:not([aria-current="page"]) { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}

@media (prefers-contrast: more) {
  :root { --line: #728095; --line-strong: #4b5c72; }
  .button, .choice, textarea { border-width: 2px; }
}