:root {
  --bg: #081c2c;
  --bg-alt: #061324;
  --bg-card: #0c2438;
  --teal: #00c4a7;
  --teal-dim: rgba(0, 196, 167, 0.12);
  --amber: #f5a623;
  --amber-dim: rgba(245, 166, 35, 0.10);
  --text: #e8f0f6;
  --text-muted: #7a96aa;
  --text-dim: #4a6575;
  --border: rgba(0, 196, 167, 0.15);
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'DM Sans', system-ui, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ── HEADER ── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 1.25rem 2.5rem;
  background: rgba(8, 28, 44, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.wordmark {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--teal);
  letter-spacing: -0.02em;
  text-decoration: none;
}
.site-header nav {
  display: flex;
  gap: 2.5rem;
}
.site-header nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: color 0.2s;
}
.site-header nav a:hover { color: var(--teal); }

/* ── SECTION SHARED ── */
.section-inner { max-width: 1200px; margin: 0 auto; padding: 0 2.5rem; }
.section-label {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--teal);
  font-weight: 500;
  margin-bottom: 1.5rem;
  font-family: var(--font-body);
}
.section-heading {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 3rem);
  font-weight: 600;
  line-height: 1.15;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}
.section-body {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 580px;
  line-height: 1.7;
}

/* ── HERO ── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 8rem 2.5rem 6rem;
}
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.22;
  animation: drift 8s ease-in-out infinite alternate;
}
.orb-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, #00c4a7 0%, transparent 70%);
  top: -10%; right: -5%;
  animation-duration: 9s;
}
.orb-2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, #f5a623 0%, transparent 70%);
  bottom: 5%; left: 20%;
  animation-duration: 12s;
  animation-delay: -4s;
  opacity: 0.12;
}
.depth-lines {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
}
.depth-line {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--teal-dim), transparent);
}
@keyframes drift {
  from { transform: translate(0, 0) scale(1); }
  to { transform: translate(30px, 20px) scale(1.05); }
}
.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4rem;
  align-items: center;
}
.hero-eyebrow {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--teal);
  margin-bottom: 1.25rem;
  font-weight: 500;
}
.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5.5vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 1.75rem;
}
.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 520px;
  line-height: 1.75;
}
.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}
.breath-ring {
  position: relative;
  width: 200px;
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--teal);
  opacity: 0.3;
  animation: breathe 5s ease-in-out infinite;
}
.ring-outer { width: 200px; height: 200px; animation-duration: 5s; }
.ring-mid { width: 148px; height: 148px; opacity: 0.5; animation-duration: 5s; animation-delay: 0.5s; border-color: var(--amber); }
.ring-inner { width: 96px; height: 96px; opacity: 0.7; animation-duration: 5s; animation-delay: 1s; }
@keyframes breathe {
  0%, 100% { transform: scale(0.92); opacity: 0.2; }
  50% { transform: scale(1.06); opacity: 0.6; }
}
.breath-label {
  position: relative;
  z-index: 1;
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
  opacity: 0.7;
}

/* ── PHYSIOLOGY ── */
.physiology {
  padding: 8rem 0;
  border-top: 1px solid var(--border);
}
.physiology .section-body { margin-bottom: 3.5rem; }
.phys-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.phys-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2.25rem;
  transition: border-color 0.3s, transform 0.3s;
}
.phys-card:hover { border-color: var(--teal); transform: translateY(-3px); }
.phys-icon {
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
  border: 1px solid var(--teal);
  display: inline-block;
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 1.25rem;
}
.phys-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}
.phys-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ── TRAINING ── */
.training {
  padding: 8rem 0;
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
}
.training-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: start;
}
.training-layout .section-body { margin-top: 1.25rem; }
.training-tier {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
}
.training-tier:first-child { border-top: 1px solid var(--border); }
.tier-number {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-dim);
  line-height: 1;
  min-width: 2rem;
  padding-top: 0.1rem;
}
.tier-ai .tier-number { color: var(--teal); }
.ai-badge {
  background: var(--teal-dim);
  border: 1px solid var(--teal);
  border-radius: 4px;
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.45rem;
  margin-top: 0.25rem;
}
.tier-content h4 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}
.tier-content p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ── PRINCIPLES ── */
.principles {
  padding: 8rem 0;
  border-top: 1px solid var(--border);
}
.principles .section-label { margin-bottom: 3rem; }
.principles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
}
.principle {
  padding: 2.5rem 2.5rem 2.5rem 0;
  border-right: 1px solid var(--border);
  padding-right: 3rem;
}
.principle:first-child { padding-left: 0; }
.principle:nth-child(2) { padding-left: 3rem; }
.principle:last-child { border-right: none; padding-left: 3rem; }
.principle-mark {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-dim);
  margin-bottom: 1.25rem;
  line-height: 1;
}
.principle h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}
.principle p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ── CLOSING ── */
.closing {
  padding: 10rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
}
.closing-inner { max-width: 800px; margin: 0 auto; }
.closing-headline {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 1.5rem;
}
.closing-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ── FOOTER ── */
.site-footer {
  padding: 3rem 0;
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.footer-brand { display: flex; flex-direction: column; gap: 0.35rem; }
.wordmark-sm {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--teal);
}
.footer-tagline {
  font-size: 0.8rem;
  color: var(--text-dim);
  letter-spacing: 0.04em;
}
.footer-note {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-style: italic;
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .phys-grid { grid-template-columns: 1fr; }
  .training-layout { grid-template-columns: 1fr; gap: 3rem; }
  .principles-grid { grid-template-columns: 1fr; gap: 2rem; }
  .principle { border-right: none; padding-left: 0 !important; padding-right: 0; border-bottom: 1px solid var(--border); }
  .site-header nav { display: none; }
}
@media (max-width: 600px) {
  .hero { padding: 7rem 1.5rem 4rem; }
  .section-inner { padding: 0 1.5rem; }
  .physiology, .training, .principles { padding: 5rem 0; }
  .closing { padding: 6rem 0; }
  .footer-inner { flex-direction: column; gap: 1rem; align-items: flex-start; }
}