:root {
  --paper: #fbf6ea;
  --paper-strong: #fffaf1;
  --ink: #052e31;
  --ink-soft: #315155;
  --teal: #00b8aa;
  --teal-deep: #08695f;
  --teal-pale: #d8f2ec;
  --coral: #a6340f;
  --line: rgba(5, 46, 49, 0.14);
  --shadow: 0 24px 80px rgba(5, 46, 49, 0.12);
  --radius-lg: 2rem;
  --radius-md: 1.35rem;
  --max: 72rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(circle at 85% 10%, rgba(0, 184, 170, 0.14), transparent 26rem),
    linear-gradient(rgba(5, 46, 49, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(5, 46, 49, 0.025) 1px, transparent 1px);
  background-size: auto, 3rem 3rem, 3rem 3rem;
  pointer-events: none;
}

a { color: var(--teal-deep); text-underline-offset: 0.18em; }
a:hover { color: var(--ink); }

img { display: block; max-width: 100%; }

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.65rem 1rem;
  border-radius: 999px;
  background: var(--ink);
  color: white;
  transform: translateY(-180%);
}

.skip-link:focus { transform: translateY(0); }

:focus-visible {
  outline: 3px solid var(--coral);
  outline-offset: 4px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(251, 246, 234, 0.9);
  backdrop-filter: blur(18px);
}

.nav,
.container {
  width: min(calc(100% - 2rem), var(--max));
  margin-inline: auto;
}

.nav {
  min-height: 4.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--ink);
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.brand img {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 0.65rem;
  box-shadow: 0 5px 14px rgba(5, 46, 49, 0.15);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-links a {
  display: flex;
  align-items: center;
  min-height: 2.75rem;
  padding: 0.55rem 0.8rem;
  border-radius: 999px;
  color: var(--ink-soft);
  font-size: 0.92rem;
  font-weight: 650;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  background: rgba(0, 184, 170, 0.12);
  color: var(--ink);
}

main { overflow: clip; }

.hero {
  padding: clamp(4rem, 9vw, 8rem) 0 clamp(4.5rem, 10vw, 8.5rem);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(18rem, 0.98fr);
  align-items: center;
  gap: clamp(3rem, 8vw, 7rem);
}

.eyebrow {
  margin: 0 0 1rem;
  color: var(--teal-deep);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.06;
  letter-spacing: -0.045em;
}

h1 {
  max-width: 12ch;
  margin-bottom: 1.35rem;
  font-size: clamp(3.4rem, 8vw, 6.8rem);
  font-weight: 850;
}

h1 em {
  color: var(--teal-deep);
  font-family: ui-serif, Georgia, serif;
  font-weight: 500;
}

h2 { font-size: clamp(2.15rem, 5vw, 4rem); }
h3 { font-size: 1.35rem; }

.lede {
  max-width: 37rem;
  margin: 0;
  color: var(--ink-soft);
  font-size: clamp(1.08rem, 2vw, 1.3rem);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem;
  margin-top: 2rem;
}

.actions.centered { justify-content: center; }
.workout-card.next-card { margin-top: 0.85rem; }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3.2rem;
  padding: 0.75rem 1.2rem;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: var(--ink);
  color: white;
  font-weight: 780;
  text-decoration: none;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.button:hover {
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(5, 46, 49, 0.2);
}

.button.secondary { background: transparent; color: var(--ink); }
.button.secondary:hover { background: var(--paper-strong); color: var(--ink); }

.platforms {
  margin: 1.6rem 0 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
  font-weight: 680;
}

.app-stage {
  position: relative;
  min-height: 34rem;
}

.app-stage::before {
  content: "";
  position: absolute;
  inset: 6% -14% 0 4%;
  border-radius: 46% 54% 43% 57%;
  background: var(--teal-pale);
  transform: rotate(-6deg);
}

.phone {
  position: absolute;
  top: 0;
  right: 5%;
  width: min(20rem, 75%);
  padding: 0.55rem;
  border: 2px solid var(--ink);
  border-radius: 2.7rem;
  background: var(--ink);
  box-shadow: var(--shadow);
  transform: rotate(3deg);
}

.screen {
  min-height: 31rem;
  padding: 1.25rem 1rem;
  border-radius: 2.2rem;
  background: var(--paper-strong);
}

.phone-top {
  width: 5rem;
  height: 1.35rem;
  margin: 0 auto 1.4rem;
  border-radius: 999px;
  background: var(--ink);
}

.screen-label { color: var(--ink-soft); font-size: 0.75rem; font-weight: 750; }
.screen-title { margin: 0.2rem 0 1.2rem; font-size: 1.7rem; font-weight: 850; letter-spacing: -0.04em; }

.workout-card,
.metric-row,
.watch-card {
  border: 1px solid var(--line);
  background: white;
}

.workout-card { padding: 1.1rem; border-radius: 1.4rem; }
.workout-card strong { display: block; font-size: 1.12rem; }
.workout-card small { color: var(--ink-soft); }

.progress-line {
  height: 0.5rem;
  margin-top: 1rem;
  overflow: hidden;
  border-radius: 999px;
  background: var(--teal-pale);
}

.progress-line span { display: block; width: 68%; height: 100%; background: var(--teal); }

.metric-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  margin-top: 0.85rem;
  overflow: hidden;
  border-radius: 1.2rem;
  background: var(--line);
}

.metric { padding: 1rem; background: white; }
.metric b { display: block; font-size: 1.35rem; }
.metric span { color: var(--ink-soft); font-size: 0.72rem; }

.watch-card {
  position: absolute;
  left: 0;
  bottom: 1.5rem;
  width: 11.5rem;
  padding: 1.15rem;
  border-radius: 2rem;
  box-shadow: var(--shadow);
  transform: rotate(-5deg);
}

.watch-card img { width: 3.35rem; border-radius: 0.95rem; }
.watch-card b { display: block; margin-top: 1rem; font-size: 1.65rem; }
.watch-card span { color: var(--ink-soft); font-size: 0.8rem; }

.section { padding: clamp(4.5rem, 9vw, 8rem) 0; }
.section.tint { background: var(--ink); color: var(--paper); }
.section.tint .eyebrow { color: #63d7ca; }
.section.tint .section-intro { color: rgba(255, 250, 241, 0.72); }

.section-head {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: end;
  gap: 3rem;
  margin-bottom: 3rem;
}

.section-head h2 { max-width: 13ch; margin-bottom: 0; }
.section-intro { max-width: 36rem; margin: 0; color: var(--ink-soft); font-size: 1.08rem; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.feature-card {
  min-height: 17rem;
  padding: 1.65rem;
  border: 1px solid rgba(255, 250, 241, 0.16);
  border-radius: var(--radius-md);
  background: rgba(255, 250, 241, 0.06);
}

.feature-card .index {
  display: inline-grid;
  width: 2.4rem;
  height: 2.4rem;
  margin-bottom: 3.5rem;
  place-items: center;
  border-radius: 50%;
  background: var(--teal);
  color: var(--ink);
  font-size: 0.78rem;
  font-weight: 900;
}

.feature-card p { margin-bottom: 0; color: rgba(255, 250, 241, 0.68); }

.principles {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: clamp(3rem, 8vw, 7rem);
  align-items: center;
}

.icon-panel {
  position: relative;
  padding: clamp(2rem, 5vw, 4rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--paper-strong);
  box-shadow: var(--shadow);
}

.icon-panel img {
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  border-radius: 22%;
}
.icon-panel::after {
  content: "On your device";
  position: absolute;
  right: -1rem;
  bottom: 1.5rem;
  padding: 0.65rem 0.95rem;
  border-radius: 999px;
  background: var(--teal);
  color: var(--ink);
  font-size: 0.75rem;
  font-weight: 850;
  transform: rotate(-4deg);
}

.check-list { margin: 2rem 0 0; padding: 0; list-style: none; }
.check-list li { position: relative; padding: 1rem 0 1rem 2.1rem; border-top: 1px solid var(--line); }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: var(--teal-deep); font-weight: 900; }

.cta {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
  padding: clamp(2rem, 5vw, 4rem);
  border-radius: var(--radius-lg);
  background: var(--teal);
}

.cta h2 { max-width: 13ch; margin-bottom: 0.7rem; }
.cta p { max-width: 38rem; margin: 0; }

.page-hero { padding: clamp(4rem, 9vw, 7rem) 0 3rem; }
.page-hero h1 { max-width: 14ch; font-size: clamp(3rem, 7vw, 5.5rem); }
.updated { display: inline-block; margin-top: 1.5rem; color: var(--ink-soft); font-size: 0.9rem; }

.document-layout {
  display: grid;
  grid-template-columns: 15rem minmax(0, 45rem);
  gap: clamp(2.5rem, 7vw, 6rem);
  align-items: start;
  padding-bottom: clamp(5rem, 10vw, 9rem);
}

.toc { position: sticky; top: 7rem; }
.toc strong { display: block; margin-bottom: 0.75rem; font-size: 0.8rem; letter-spacing: 0.1em; text-transform: uppercase; }
.toc ol { margin: 0; padding-left: 1.25rem; color: var(--ink-soft); font-size: 0.9rem; }
.toc li + li { margin-top: 0.45rem; }
.toc a { color: inherit; text-decoration: none; }
.toc a:hover { color: var(--ink); text-decoration: underline; }

.prose { min-width: 0; }
.prose section { scroll-margin-top: 7rem; padding: 0 0 2.5rem; }
.prose section + section { padding-top: 2.5rem; border-top: 1px solid var(--line); }
.prose h2 { margin-bottom: 1rem; font-size: clamp(1.75rem, 4vw, 2.5rem); }
.prose h3 { margin-top: 1.8rem; margin-bottom: 0.5rem; letter-spacing: -0.025em; }
.prose p, .prose li { color: var(--ink-soft); }
.prose strong { color: var(--ink); }
.prose ul, .prose ol { padding-left: 1.25rem; }
.prose li + li { margin-top: 0.5rem; }

.notice,
.support-card {
  padding: 1.4rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper-strong);
}

.notice { margin-bottom: 3rem; border-left: 0.35rem solid var(--teal); }
.notice p { margin: 0; }

.support-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin: 1.5rem 0; }
.support-card h3 { margin-bottom: 0.6rem; }
.support-card p { margin-bottom: 0; }

.site-footer { border-top: 1px solid var(--line); }
.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 2rem;
  min-height: 8rem;
  padding: 1.5rem 0;
}
.footer-grid p { margin: 0.35rem 0 0; color: var(--ink-soft); font-size: 0.84rem; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 0.3rem 1rem; }
.footer-links a { color: var(--ink-soft); font-size: 0.86rem; font-weight: 650; text-decoration: none; }
.footer-links a:hover { color: var(--ink); text-decoration: underline; }

.not-found { min-height: calc(100vh - 13rem); display: grid; place-items: center; text-align: center; }
.not-found h1 { max-width: none; margin-inline: auto; }
.not-found .lede { margin-inline: auto; }

@media (max-width: 800px) {
  .nav { align-items: flex-start; padding-block: 0.85rem; }
  .nav-links { flex-wrap: wrap; justify-content: flex-end; }
  .hero-grid, .section-head, .principles, .cta, .document-layout { grid-template-columns: 1fr; }
  .hero { padding-top: 4.5rem; }
  .app-stage { min-height: 31rem; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .document-layout { gap: 2rem; }
  .toc { position: static; padding-bottom: 1.5rem; border-bottom: 1px solid var(--line); }
  .cta { align-items: start; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
}

@media (max-width: 560px) {
  .nav { display: block; }
  .brand { margin-bottom: 0.75rem; }
  .nav-links { justify-content: flex-start; gap: 0; }
  .nav-links a { padding: 0.42rem 0.6rem; font-size: 0.82rem; }
  h1 { font-size: clamp(3rem, 16vw, 4.5rem); }
  .phone { right: 0; width: 82%; }
  .watch-card { left: 0; width: 10rem; }
  .feature-grid, .support-grid { grid-template-columns: 1fr; }
  .feature-card { min-height: 14rem; }
  .feature-card .index { margin-bottom: 2rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #062a2c;
    --paper-strong: #0b3537;
    --ink: #f8f2e7;
    --ink-soft: #bed0cb;
    --teal: #4fd1c1;
    --teal-deep: #71ded1;
    --teal-pale: #154d4a;
    --line: rgba(248, 242, 231, 0.14);
    --shadow: 0 24px 80px rgba(0, 0, 0, 0.3);
  }
  .site-header { background: rgba(6, 42, 44, 0.9); }
  .section.tint { background: #031d1f; }
  .workout-card, .metric-row, .watch-card, .metric { background: var(--paper-strong); }
  .metric-row { background: var(--line); }
  .button { background: var(--ink); color: #052e31; }
  .button:hover { color: #052e31; }
}