:root {
  --bg: #000;
  --surface: #1c1c1e;
  --border: #3a3a3c;
  --text: #fff;
  --muted: #8e8e93;
  --accent: #64d2ff;
  --accent-hover: #8fdfff;
}

/* Reset */
*, ::before, ::after { box-sizing: border-box; }
html {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 106.25%; /* 17px, the iOS body size */
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  background: var(--bg);
  color: var(--text);
}
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
body { margin: 0; }
h1, h2, h3, p, dl, dd, blockquote, ul, figure { margin: 0; }
ul { list-style: none; padding: 0; }
img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button, input, textarea { font: inherit; color: inherit; margin: 0; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

/* Type scale: 17 / 22 / 34 / 56 */
h1 { font-size: clamp(2.25rem, 5vw, 3.3rem); line-height: 1.05; font-weight: 600; letter-spacing: -0.02em; }
h2 { font-size: 2rem; line-height: 1.2; font-weight: 600; }
dt, figcaption strong { font-size: 1.3rem; line-height: 1.3; font-weight: 600; }

/* Layout */
.container { max-width: 60rem; margin-inline: auto; padding-inline: 1.5rem; }
.section { padding-block: 4rem; }
@media (min-width: 768px) { .section { padding-block: 5rem; } }
.prose { max-width: 38rem; margin-top: 1.25rem; color: var(--muted); }
.link { color: var(--accent); }
.link:hover { text-decoration: underline; }
.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; }

/* Nav */
.nav .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0.5rem 1.5rem; padding-block: 1.25rem; }
.nav-brand { display: flex; align-items: center; gap: 0.75rem; font-weight: 600; }
.nav-brand img { width: 2rem; height: 2rem; border-radius: 0.5rem; }
.nav-links { display: flex; gap: 1.5rem; color: var(--muted); }
.nav-links a:hover { color: var(--text); }

/* Hero */
.hero { padding-top: 2rem; }
.hero .container { display: grid; gap: 3rem; align-items: center; }
.hero-lead { margin-top: 1.5rem; max-width: 24rem; font-size: 1.3rem; line-height: 1.4; color: var(--muted); }
.hero-cta { display: inline-block; margin-top: 2.5rem; }
.hero-cta img { width: 11rem; }
.hero video { width: 18rem; margin-inline: auto; border-radius: 15.5% / 7.4%; }
@media (min-width: 900px) {
  .hero .container { grid-template-columns: 1fr auto; gap: 4rem; }
  .hero video { width: 22rem; margin: 0; }
}

/* How it's different */
.diagrams { margin-top: 3rem; display: grid; gap: 2.5rem; }
@media (min-width: 640px) { .diagrams { grid-template-columns: repeat(3, 1fr); gap: 3rem; } }
.diagrams svg { width: 100%; max-width: 18rem; color: var(--accent); }
.diagrams .scale { stroke: var(--border); }
.diagrams figcaption { margin-top: 1rem; }
.diagrams figcaption strong { display: block; }
.diagrams figcaption span { color: var(--muted); }

/* FAQ */
.faq dl { margin-top: 2.5rem; max-width: 38rem; display: grid; gap: 2rem; }
.faq dd { margin-top: 0.5rem; color: var(--muted); }

/* Reviews */
.reviews ul { margin-top: 2.5rem; display: grid; gap: 2.5rem; }
@media (min-width: 768px) { .reviews ul { grid-template-columns: repeat(3, 1fr); gap: 3rem; } }
.reviews blockquote p { font-size: 1.2rem; line-height: 1.45; }
.reviews figcaption { margin-top: 1rem; color: var(--muted); }
.reviews figcaption a { color: var(--accent); }
.reviews figcaption a:hover { text-decoration: underline; }

/* Contact */
.contact form { margin-top: 2.5rem; max-width: 32rem; display: grid; gap: 1rem; }
.contact input, .contact textarea { width: 100%; padding: 0.75rem 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: 0.5rem; }
.contact ::placeholder { color: var(--muted); }
.contact input:focus, .contact textarea:focus { outline: none; border-color: var(--accent); }
.contact button { justify-self: start; padding: 0.75rem 1.5rem; border: 0; border-radius: 0.5rem; background: var(--accent); color: #000; font-weight: 600; cursor: pointer; }
.contact button:hover { background: var(--accent-hover); }

/* Footer */
.footer { border-top: 1px solid var(--surface); color: var(--muted); }
.footer .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 1rem 1.5rem; padding-block: 2rem; }
.footer nav { display: flex; gap: 1.5rem; }
.footer-social { display: flex; gap: 1rem; }
.footer-social svg { width: 1.5rem; height: 1.5rem; }
.footer a:hover { color: var(--text); }

/* Privacy */
.privacy .container { max-width: 38rem; }
.privacy h1 { font-size: 2rem; }
.privacy .updated { margin-top: 0.75rem; color: var(--muted); }
.privacy p { margin-top: 1.5rem; color: var(--muted); }
.privacy .lead { margin-top: 2rem; font-size: 1.2rem; color: var(--text); }