/* ==========================================================================
   FitnessKit website — design system
   Mirrors the app's DesignSystem tokens (Colors / Typography / Spacing /
   GlassModifier / BorderRadius). Self-contained: no build step, no framework.
   ========================================================================== */

:root {
  /* Brand */
  --brand: #2563EB;
  --brand-hover: #1D4FD8;
  --brand-subtle: #EAF1FE;
  --on-brand: #FFFFFF;

  /* AI accent + gradient */
  --ai-accent: #7C3AED;
  --ai-glow: rgba(124, 58, 237, .35);
  --brand-gradient: linear-gradient(135deg, #2563EB, #7C3AED);

  /* Semantic */
  --teal: #0D9488;
  --indigo: #4F46E5;
  --success: #16A34A;
  --danger: #DC2626;
  --warning: #F59E0B;

  /* Surfaces / text */
  --bg: #F7F8FA;
  --bg-elevated: #FFFFFF;
  --card: rgba(255, 255, 255, .60);
  --card-solid: #FFFFFF;
  --hairline: rgba(120, 120, 128, .30);
  --label: #11151C;
  --label-secondary: #5b6472;
  --label-tertiary: #8b93a1;

  /* Radii */
  --r-mini: 4px;
  --r-inner: 8px;
  --r-outer: 12px;
  --r-modal: 24px;
  --r-pill: 980px;

  /* Elevation (key + ambient) */
  --elev-2: 0 1px 4px rgba(0, 0, 0, .04), 0 2px 8px rgba(0, 0, 0, .03);
  --elev-3: 0 4px 10px rgba(0, 0, 0, .06), 0 8px 24px rgba(0, 0, 0, .05);

  /* Spacing scale */
  --s-xs: 4px;
  --s-s: 8px;
  --s-m: 12px;
  --s-l: 16px;
  --s-xl: 24px;
  --s-xxl: 32px;

  --font: -apple-system, BlinkMacSystemFont, system-ui, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-rounded: ui-rounded, "SF Pro Rounded", "Hiragino Maru Gothic ProN", var(--font);

  --maxw: 1120px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand: #4D8DFF;
    --brand-hover: #6BA1FF;
    --brand-subtle: #15233D;
    --ai-accent: #9B6BFF;
    --ai-glow: rgba(155, 107, 255, .35);
    --brand-gradient: linear-gradient(135deg, #4D8DFF, #9B6BFF);

    --teal: #2DD4BF;
    --indigo: #818CF8;
    --success: #22C55E;
    --danger: #F87171;
    --warning: #FBBF24;

    --bg: #0E1116;
    --bg-elevated: #171B22;
    --card: rgba(30, 33, 40, .55);
    --card-solid: #171B22;
    --hairline: rgba(120, 120, 128, .30);
    --label: #F2F4F7;
    --label-secondary: #a7afbe;
    --label-tertiary: #79808f;

    --elev-2: 0 1px 4px rgba(0, 0, 0, .30), 0 2px 8px rgba(0, 0, 0, .24);
    --elev-3: 0 4px 10px rgba(0, 0, 0, .35), 0 8px 24px rgba(0, 0, 0, .30);
  }
}

/* ---------- Reset / base ---------------------------------------------------- */

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--label);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-rounded);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--label);
  margin: 0 0 var(--s-m);
}

h1 { font-size: clamp(2.1rem, 5vw, 3.4rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.3rem); }
h3 { font-size: 1.25rem; }

p { margin: 0 0 var(--s-l); color: var(--label-secondary); }

a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-hover); text-decoration: underline; }

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

hr { border: none; border-top: 1px solid var(--hairline); margin: var(--s-xl) 0; }

/* ---------- Layout ---------------------------------------------------------- */

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 var(--s-xl); }

section { padding: 88px 0; }

.section-narrow { max-width: 760px; margin: 0 auto; }

.eyebrow {
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--brand);
  margin-bottom: var(--s-s);
}

.text-center { text-align: center; }
.muted { color: var(--label-secondary); }
.small { font-size: .9rem; }

/* ---------- Navbar ---------------------------------------------------------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--card);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: .5px solid var(--hairline);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 12px var(--s-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-l);
}

.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand img { height: 30px; width: auto; }
.brand-name {
  font-family: var(--font-rounded);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--label);
  letter-spacing: -0.01em;
}

.nav-links { display: flex; align-items: center; gap: var(--s-xl); }
.nav-links a { color: var(--label-secondary); font-size: .95rem; font-weight: 600; }
.nav-links a:hover { color: var(--label); text-decoration: none; }

/* logo variants swap with theme */
.logo-dark { display: block; }
.logo-light { display: none; }
@media (prefers-color-scheme: dark) {
  .logo-dark { display: none; }
  .logo-light { display: block; }
}

/* ---------- Buttons --------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-s);
  padding: 13px 24px;
  border-radius: var(--r-outer);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .15s ease, opacity .15s ease, background .15s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: scale(.98); }

.btn-primary { background: var(--brand); color: var(--on-brand); box-shadow: var(--elev-2); }
.btn-primary:hover { background: var(--brand-hover); color: var(--on-brand); }

.btn-secondary { background: var(--brand-subtle); color: var(--brand); border-color: var(--brand); }
.btn-secondary:hover { color: var(--brand); opacity: .85; }

.btn-ai { background: var(--brand-gradient); color: #fff; box-shadow: 0 4px 12px var(--ai-glow); }
.btn-ai:hover { color: #fff; opacity: .92; }

/* App Store badge link */
.badge-link img { height: 52px; width: auto; }
.badge-link:hover { text-decoration: none; opacity: .9; }

/* ---------- Cards ----------------------------------------------------------- */

.card {
  background: var(--card);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: .5px solid var(--hairline);
  border-radius: var(--r-outer);
  box-shadow: var(--elev-3);
  padding: var(--s-xl);
}

.card-solid { background: var(--card-solid); }

.icon-badge {
  width: 52px;
  height: 52px;
  border-radius: var(--r-inner);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: var(--s-m);
  background: color-mix(in srgb, var(--brand) 12%, transparent);
}
.icon-badge.ai { background: color-mix(in srgb, var(--ai-accent) 14%, transparent); }

/* ---------- Hero ------------------------------------------------------------ */

.hero {
  position: relative;
  padding: 96px 0 72px;
  overflow: hidden;
  background:
    radial-gradient(1000px 500px at 15% -10%, color-mix(in srgb, var(--brand) 22%, transparent), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, color-mix(in srgb, var(--ai-accent) 18%, transparent), transparent 55%),
    var(--bg);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: var(--s-xxl);
  align-items: center;
}

.hero h1 { margin-bottom: var(--s-l); }
.hero .lead { font-size: 1.2rem; max-width: 30ch; }
.hero-cta { display: flex; align-items: center; gap: var(--s-l); flex-wrap: wrap; margin-top: var(--s-xl); }

.hero-visual { display: flex; justify-content: center; }
.hero-visual img {
  max-height: 560px;
  width: auto;
  border-radius: var(--r-modal);
  box-shadow: var(--elev-3);
}

/* ---------- Feature grid ---------------------------------------------------- */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--s-xl);
}

.feature h3 { margin-bottom: var(--s-s); }
.feature p { margin-bottom: 0; font-size: .98rem; }

/* ---------- CTA band -------------------------------------------------------- */

.cta-band {
  background: var(--brand-gradient);
  border-radius: var(--r-modal);
  padding: 56px var(--s-xxl);
  text-align: center;
  color: #fff;
}
.cta-band h2 { color: #fff; }
.cta-band p { color: rgba(255, 255, 255, .88); }

/* ---------- Deep-link (open) page ------------------------------------------ */

.open-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s-xl);
  background:
    radial-gradient(800px 500px at 20% -10%, color-mix(in srgb, var(--brand) 22%, transparent), transparent 60%),
    radial-gradient(800px 500px at 100% 10%, color-mix(in srgb, var(--ai-accent) 18%, transparent), transparent 55%),
    var(--bg);
}
.open-card { max-width: 440px; width: 100%; text-align: center; }
.open-card .app-icon { width: 84px; height: 84px; border-radius: 20px; margin: 0 auto var(--s-l); box-shadow: var(--elev-2); }
.open-card h1 { font-size: 1.7rem; }
.code-chip {
  display: inline-block;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: .18em;
  padding: 12px 22px;
  border-radius: var(--r-inner);
  background: var(--brand-subtle);
  color: var(--brand);
  margin: var(--s-s) 0 var(--s-l);
}
.open-actions { display: flex; flex-direction: column; align-items: center; gap: var(--s-m); margin-top: var(--s-l); }

/* ---------- Legal / prose --------------------------------------------------- */

.prose { max-width: 760px; margin: 0 auto; }
.prose h1 { margin-bottom: var(--s-l); }
.prose h2 { margin-top: var(--s-xl); font-size: 1.4rem; }
.prose h3 { margin-top: var(--s-l); }
.prose p, .prose li { color: var(--label-secondary); }
.prose ul, .prose ol { padding-left: 1.3em; margin-bottom: var(--s-l); }
.prose a { text-decoration: underline; }

/* ---------- Footer ---------------------------------------------------------- */

.footer {
  border-top: .5px solid var(--hairline);
  padding: var(--s-xxl) 0;
  background: var(--bg);
}
.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s-xl);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-l);
}
.footer-links { display: flex; flex-wrap: wrap; gap: var(--s-xl); }
.footer-links a { color: var(--label-secondary); font-size: .9rem; font-weight: 600; }
.footer-links a:hover { color: var(--label); text-decoration: none; }
.footer-copy { color: var(--label-tertiary); font-size: .85rem; }

/* ---------- Responsive ------------------------------------------------------ */

@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero .lead { max-width: none; margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-visual { order: -1; }
  .hero-visual img { max-height: 420px; }
  .nav-links { gap: var(--s-l); }
  section { padding: 64px 0; }
}

@media (max-width: 560px) {
  .nav-links a.nav-hide-sm { display: none; }
  .footer-inner { flex-direction: column; text-align: center; }
  .footer-links { justify-content: center; }
}