/* ============================================================
   BOTBUHDY BREATHE — A BotBuhdy Exploration
   World-class dark aesthetic — v1.0
   Space Grotesk · Inter · JetBrains Mono
   Breath-themed: Teal, Lavender, Amber on Deep Dark
   ============================================================ */

:root {
  /* Core palette */
  --bg-deep:       #03080f;
  --bg-mid:        #060c14;
  --bg-card:       #090f1c;
  --bg-card-hover: #0d1425;

  /* Breath-themed: teal/cyan primary */
  --breath-teal:   #00CED1;
  --breath-cyan:   #00BFA5;
  --breath-aqua:   #26C6DA;
  --breath-mint:   #00E5CC;

  /* Indigo/lavender secondary */
  --breath-indigo: #7C4DFF;
  --breath-violet: #B388FF;
  --breath-purple: #9575CD;
  --breath-deep-purple: #5E35B1;

  /* Warm amber/gold accent */
  --breath-amber:  #FFB300;
  --breath-gold:   #FFCA28;
  --breath-warm:   #FF8F00;

  /* Calm blue (kept for harmony) */
  --calm-blue:     #29B6F6;
  --calm-deep:     #0288D1;

  /* Text */
  --text-primary:  #E8EDF8;
  --text-muted:    #7A90B0;
  --text-dim:      #3E5070;

  /* Fonts */
  --font-display: 'Space Grotesk', -apple-system, sans-serif;
  --font-body:    'Inter', -apple-system, sans-serif;
  --font-mono:    'JetBrains Mono', 'Courier New', monospace;
  --font-serif:   Georgia, 'Times New Roman', serif;

  /* Glows */
  --glow-teal:    0 0 30px rgba(0, 206, 209, 0.35);
  --glow-mint:    0 0 30px rgba(0, 229, 204, 0.35);
  --glow-violet:  0 0 30px rgba(179, 136, 255, 0.35);
  --glow-amber:   0 0 30px rgba(255, 179, 0, 0.3);

  /* Borders */
  --border-subtle: rgba(0, 206, 209, 0.10);
  --border-glow:   rgba(0, 206, 209, 0.45);

  /* Transitions */
  --transition-base: 0.4s ease-out;
  --transition-fast: 0.2s ease-out;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.85;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  animation: body-fade-in 0.6s ease-out both;
}

@keyframes body-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ── Grain Overlay ── */
.grain-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.022;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 200px 200px;
}

/* ── Grid Background ── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 206, 209, 0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 206, 209, 0.015) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
}

/* ── Layout ── */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* ============================================================
   HEADER
   ============================================================ */
.breathe-topbar {
  background: rgba(3, 8, 15, 0.98);
  border-bottom: 1px solid rgba(0, 206, 209, 0.04);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.3rem 1.5rem;
}
.topbar-back {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: color 0.2s;
}
.topbar-back:hover { color: var(--breath-teal); }
.topbar-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.5;
}

/* ── Site Header ── */
.site-header {
  background: rgba(3, 8, 15, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 206, 209, 0.08);
  position: sticky;
  top: 0;
  z-index: 500;
  padding: 0;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.6rem 1.5rem;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}
.logo-pulse {
  font-size: 1.5rem;
  animation: pulse-breathe 5s ease-in-out infinite;
}
.logo-text {
  display: flex;
  flex-direction: column;
}
.logo-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--breath-mint);
  letter-spacing: 0.02em;
  line-height: 1.2;
}
.logo-sub {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Mobile back button */
.mobile-back-btn {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--border-subtle);
  border-radius: 5px;
  transition: all 0.2s;
}
.mobile-back-btn:hover { color: var(--breath-mint); border-color: var(--breath-mint); }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 8px 10px;
  cursor: pointer;
  transition: border-color 0.2s;
}
.hamburger:hover { border-color: var(--breath-teal); }
.hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--breath-mint);
  border-radius: 2px;
  transition: all 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Navigation Bar ── */
.breathe-nav {
  background: rgba(4, 9, 18, 0.95);
  border-bottom: 1px solid rgba(0, 206, 209, 0.06);
  position: sticky;
  top: 50px;
  z-index: 499;
  overflow-x: auto;
  scrollbar-width: none;
}
.breathe-nav::-webkit-scrollbar { display: none; }
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1rem;
  white-space: nowrap;
}
.nav-link {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.65rem 1rem;
  font-family: var(--font-display);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
}
.nav-link:hover {
  color: var(--breath-mint);
  background: rgba(0, 229, 204, 0.03);
}
.nav-link.active {
  color: var(--breath-mint);
  border-bottom-color: var(--breath-mint);
}
.nav-icon { font-size: 0.85rem; }

/* ── Mobile Nav Overlay ── */
.mobile-nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(3, 8, 15, 0.99);
  z-index: 600;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
  overflow-y: scroll;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}
.mobile-nav-overlay.open { opacity: 1; visibility: visible; }
.mobile-nav-inner {
  max-width: 400px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 3rem;
}
.mobile-nav-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-subtle);
}
.mobile-nav-title {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--breath-mint);
}
.mobile-nav-close {
  background: none;
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 0.3rem 0.7rem;
  color: var(--text-muted);
  font-size: 1.1rem;
  cursor: pointer;
  transition: all 0.2s;
}
.mobile-nav-close:hover { color: var(--breath-mint); border-color: var(--breath-teal); }
.mobile-nav-links {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.mobile-nav-links a {
  display: block;
  padding: 0.85rem 0.6rem;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 206, 209, 0.06);
  transition: all 0.15s;
}
.mobile-nav-links a:hover {
  color: var(--breath-mint);
  padding-left: 1.2rem;
  background: rgba(0, 229, 204, 0.03);
}
.mobile-nav-links a.active {
  color: var(--breath-mint);
  font-weight: 600;
  border-left: 3px solid var(--breath-mint);
  padding-left: 0.8rem;
}
.mobile-nav-foot {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
}
.mobile-back {
  display: block;
  text-align: center;
  padding: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-dim);
  text-decoration: none;
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  transition: all 0.2s;
}
.mobile-back:hover { color: var(--breath-teal); border-color: var(--breath-teal); }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  margin-top: 7rem;
  position: relative;
  background: linear-gradient(180deg, transparent 0%, rgba(0,206,209,0.015) 100%);
}
.footer-wave {
  position: relative;
  height: 60px;
  overflow: hidden;
}
.footer-wave svg {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 100%;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.3fr 2fr;
  gap: 3rem;
  max-width: 1120px;
  margin: 0 auto;
  padding: 3rem 1.5rem 2.5rem;
}
.footer-brand-col {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.footer-logo-mark {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.footer-pulse {
  font-size: 1.8rem;
  animation: pulse-breathe 5s ease-in-out infinite;
}
.footer-brand-text {
  display: flex;
  flex-direction: column;
}
.footer-brand-name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--breath-mint);
}
.footer-brand-sub {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.footer-description {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
}
.footer-disclaimer-text {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  letter-spacing: 0.04em;
  padding: 0.6rem 0.8rem;
  background: rgba(0,206,209,0.03);
  border: 1px solid rgba(0,206,209,0.06);
  border-radius: 6px;
}
.footer-nav-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.footer-col {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.footer-col-title {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--breath-teal);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  padding-bottom: 0.5rem;
  margin-bottom: 0.2rem;
  border-bottom: 1px solid rgba(0,206,209,0.1);
}
.footer-col a {
  font-family: var(--font-body);
  font-size: 0.82rem;
  color: var(--text-dim);
  text-decoration: none;
  padding: 0.2rem 0;
  transition: all 0.2s;
}
.footer-col a:hover {
  color: var(--breath-mint);
  padding-left: 0.4rem;
}
.footer-bottom-bar {
  border-top: 1px solid rgba(0,206,209,0.07);
  background: rgba(0,0,0,0.2);
}
.footer-bottom-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.06em;
}
.footer-bottom-inner strong { color: var(--text-muted); }
.footer-sep { color: var(--breath-amber); opacity: 0.4; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding: 6rem 0 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* gradient placeholder */
.hero-bg-placeholder {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 40%,
    rgba(0, 206, 209, 0.10) 0%,
    rgba(124, 77, 255, 0.07) 50%,
    transparent 100%);
}

.hero > *:not(.hero-bg-placeholder) {
  position: relative;
  z-index: 1;
}
.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 140px;
  background: linear-gradient(transparent, var(--bg-deep));
  pointer-events: none;
  z-index: 2;
}
.hero-icon {
  font-size: 3.5rem;
  display: block;
  margin-bottom: 1.5rem;
  animation: float-breathe 7s ease-in-out infinite;
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5.5vw, 4.2rem);
  font-weight: 700;
  line-height: 1.05;
  margin-bottom: 1.5rem;
  background: linear-gradient(270deg, var(--breath-mint), var(--breath-teal), var(--breath-violet), var(--breath-mint));
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: shimmer-gradient 9s ease-in-out infinite;
}
@keyframes shimmer-gradient {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
.hero-subtitle {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 2.5rem;
  line-height: 1.9;
  font-style: italic;
}
.hero-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--breath-amber);
  border: 1px solid rgba(255, 179, 0, 0.35);
  padding: 0.45rem 1.2rem;
  border-radius: 4px;
  background: rgba(255, 179, 0, 0.05);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: pulse-amber 5s ease-in-out infinite;
}

/* ── Page Header (inner pages) ── */
.page-header {
  padding: 4rem 0 2.5rem;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 3.5rem;
  position: relative;
  overflow: hidden;
}
.page-header-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: radial-gradient(ellipse 70% 80% at 10% 50%,
    rgba(0, 206, 209, 0.05) 0%,
    transparent 70%);
  pointer-events: none;
}
.page-header > *:not(.page-header-bg) { position: relative; z-index: 1; }
.page-icon {
  font-size: 2.8rem;
  margin-bottom: 1rem;
  display: block;
}
.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.5vw, 3rem);
  font-weight: 700;
  background: linear-gradient(135deg, var(--breath-mint), var(--breath-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.75rem;
  line-height: 1.1;
}
.page-header .subtitle {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--text-muted);
  font-style: italic;
  max-width: 640px;
  line-height: 1.8;
}
.page-header .page-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
}
.page-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.25rem 0.8rem;
  border-radius: 4px;
  background: rgba(0, 206, 209, 0.07);
  border: 1px solid rgba(0, 206, 209, 0.18);
  color: var(--breath-teal);
}
.page-tag.tag-violet {
  background: rgba(124, 77, 255, 0.07);
  border-color: rgba(124, 77, 255, 0.18);
  color: var(--breath-violet);
}
.page-tag.tag-amber {
  background: rgba(255, 179, 0, 0.07);
  border-color: rgba(255, 179, 0, 0.22);
  color: var(--breath-amber);
}

/* ============================================================
   IMAGE PLACEHOLDER
   ============================================================ */
.hero-img-placeholder {
  width: 100%;
  max-width: 900px;
  margin: 0 auto 3rem;
  border-radius: 12px;
  border: 1px solid var(--border-subtle);
  overflow: hidden;
  position: relative;
  z-index: 1;
  aspect-ratio: 16/7;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 12px 60px rgba(0, 0, 0, 0.7), var(--glow-teal);
}

body.page-home       .hero-img-placeholder { background: radial-gradient(ellipse at 40% 50%, rgba(0,206,209,0.28) 0%, rgba(124,77,255,0.18) 50%, rgba(3,8,15,0.9) 100%); }
body.page-anatomy    .hero-img-placeholder { background: radial-gradient(ellipse at 50% 40%, rgba(0,229,204,0.22) 0%, rgba(41,182,246,0.18) 60%, rgba(3,8,15,0.9) 100%); }
body.page-techniques .hero-img-placeholder { background: radial-gradient(ellipse at 30% 60%, rgba(124,77,255,0.28) 0%, rgba(0,206,209,0.15) 60%, rgba(3,8,15,0.9) 100%); }
body.page-kriya      .hero-img-placeholder { background: radial-gradient(ellipse at 60% 40%, rgba(255,179,0,0.18) 0%, rgba(124,77,255,0.22) 50%, rgba(3,8,15,0.9) 100%); }
body.page-science    .hero-img-placeholder { background: radial-gradient(ellipse at 45% 55%, rgba(0,229,204,0.18) 0%, rgba(0,206,209,0.15) 50%, rgba(3,8,15,0.9) 100%); }
body.page-practice   .hero-img-placeholder { background: radial-gradient(ellipse at 50% 50%, rgba(0,206,209,0.22) 0%, rgba(6,12,20,0.9) 100%); }
body.page-references .hero-img-placeholder { background: radial-gradient(ellipse at 50% 50%, rgba(124,77,255,0.22) 0%, rgba(94,53,177,0.12) 50%, rgba(3,8,15,0.9) 100%); }

.hero-img-placeholder .placeholder-content {
  text-align: center;
  z-index: 2;
}
.hero-img-placeholder .placeholder-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 0.5rem;
  opacity: 0.6;
}
.hero-img-placeholder .placeholder-text {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.hero-img-placeholder::after {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent 0px,
    transparent 2px,
    rgba(0, 206, 209, 0.012) 2px,
    rgba(0, 206, 209, 0.012) 3px
  );
  pointer-events: none;
}

/* ============================================================
   SECTIONS & CARDS
   ============================================================ */
.section { margin-bottom: 4.5rem; }

.section-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--breath-teal);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  margin-bottom: 1.75rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.section-title::before {
  content: '';
  display: block;
  width: 28px;
  height: 1px;
  background: var(--breath-teal);
  opacity: 0.6;
}
.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--border-subtle), transparent);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 1.5rem;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(0, 229, 204, 0.55), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}
.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 206, 209, 0.25);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4), 0 8px 40px rgba(0, 206, 209, 0.08);
  transform: translateY(-3px);
}
.card:hover::before { opacity: 1; }

.card-title {
  font-family: var(--font-display);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--breath-mint);
  margin-bottom: 0.6rem;
  letter-spacing: 0.02em;
}
.card-body {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.75;
}
.card-icon {
  font-size: 1.8rem;
  margin-bottom: 0.75rem;
  display: block;
}

/* Card Grids */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}
.card-grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}
.card-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

/* ── Stat Cards ── */
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}
.stat-card::before {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--breath-teal), var(--breath-mint));
  opacity: 0.5;
}
.stat-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,206,209,0.08); }
.stat-number {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--breath-mint), var(--breath-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 0.4rem;
}
.stat-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ── Nav Cards (home page) ── */
.nav-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}
.nav-card {
  display: block;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 1.5rem;
  text-decoration: none;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}
.nav-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(0, 229, 204, 0.45), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}
.nav-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 229, 204, 0.28);
  transform: translateY(-4px);
  box-shadow: 0 8px 40px rgba(0, 206, 209, 0.10);
}
.nav-card:hover::before { opacity: 1; }
.nav-card-icon {
  font-size: 2.2rem;
  display: block;
  margin-bottom: 0.75rem;
}
.nav-card-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--breath-mint);
  margin-bottom: 0.5rem;
}
.nav-card-desc {
  font-size: 0.87rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── Technique Cards ── */
.technique-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  overflow: hidden;
  transition: border-color 0.3s;
}
.technique-card:hover { border-color: rgba(0, 206, 209, 0.22); }
.technique-header {
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  user-select: none;
}
.technique-header:hover { background: rgba(0,206,209,0.03); }
.technique-header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex: 1;
}
.technique-emoji { font-size: 1.6rem; flex-shrink: 0; }
.technique-name {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.15rem;
}
.technique-origin {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  letter-spacing: 0.06em;
}
.technique-badges {
  display: flex;
  gap: 0.4rem;
  flex-shrink: 0;
}
.badge {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 3px;
  white-space: nowrap;
}
.badge-beginner    { background: rgba(0,206,209,0.10);  border: 1px solid rgba(0,206,209,0.25);  color: var(--breath-teal); }
.badge-intermediate{ background: rgba(255,179,0,0.09);  border: 1px solid rgba(255,179,0,0.22);  color: var(--breath-amber); }
.badge-advanced    { background: rgba(124,77,255,0.10); border: 1px solid rgba(124,77,255,0.25); color: var(--breath-violet); }
.badge-calm        { background: rgba(0,206,209,0.08);  border: 1px solid rgba(0,206,209,0.20);  color: var(--breath-teal); }
.badge-energy      { background: rgba(255,143,0,0.09);  border: 1px solid rgba(255,143,0,0.22);  color: #ff8f00; }
.badge-sleep       { background: rgba(94,53,177,0.10);  border: 1px solid rgba(94,53,177,0.25);  color: #9575cd; }
.badge-meditation  { background: rgba(124,77,255,0.10); border: 1px solid rgba(124,77,255,0.25); color: var(--breath-violet); }
.badge-healing     { background: rgba(38,198,218,0.09); border: 1px solid rgba(38,198,218,0.22); color: var(--breath-aqua); }

.technique-chevron {
  color: var(--text-dim);
  font-size: 0.8rem;
  transition: transform 0.3s;
  flex-shrink: 0;
}
.technique-card.open .technique-chevron { transform: rotate(180deg); }
.technique-body {
  display: none;
  padding: 0 1.5rem 1.5rem;
  border-top: 1px solid var(--border-subtle);
}
.technique-card.open .technique-body { display: block; }
.technique-section-title {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--breath-teal);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 1rem 0 0.4rem;
}
.technique-steps {
  list-style: none;
  padding: 0;
  counter-reset: step-counter;
}
.technique-steps li {
  padding: 0.35rem 0 0.35rem 2rem;
  position: relative;
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.6;
  counter-increment: step-counter;
}
.technique-steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 0.35rem;
  width: 1.4rem;
  height: 1.4rem;
  background: rgba(0,206,209,0.12);
  border: 1px solid rgba(0,206,209,0.22);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--breath-teal);
  line-height: 1.4rem;
  text-align: center;
}
.technique-warning {
  margin-top: 0.75rem;
  padding: 0.6rem 0.9rem;
  background: rgba(255,143,0,0.06);
  border: 1px solid rgba(255,143,0,0.18);
  border-radius: 6px;
  font-size: 0.83rem;
  color: #ff8f00;
}
.technique-warning::before { content: '⚠️ '; }

/* Category filter bar */
.filter-bar {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}
.filter-btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.35rem 0.9rem;
  border-radius: 5px;
  border: 1px solid var(--border-subtle);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}
.filter-btn:hover { border-color: var(--breath-teal); color: var(--breath-teal); }
.filter-btn.active { background: rgba(0,206,209,0.10); border-color: var(--breath-teal); color: var(--breath-mint); }

/* ── SVG Diagram containers ── */
.diagram-container {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 2rem;
  margin: 1.5rem 0;
  text-align: center;
}
.diagram-container svg {
  max-width: 100%;
  height: auto;
}
.diagram-caption {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 1rem;
}

/* ── Two-column anatomy layout ── */
.anatomy-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}
@media (max-width: 768px) {
  .anatomy-split { grid-template-columns: 1fr; }
}

/* ── Practice / Interactive ── */
.practice-hero {
  padding: 3rem 0 2rem;
  text-align: center;
}

.breathing-circle-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
  padding: 2.5rem 0;
}

.breathing-circle-outer {
  position: relative;
  width: 260px;
  height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.breathing-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px solid rgba(0,206,209,0.15);
  animation: ring-pulse 4s ease-in-out infinite;
}
.breathing-ring:nth-child(2) { inset: -12px; animation-delay: 0.5s; opacity: 0.6; }
.breathing-ring:nth-child(3) { inset: -24px; animation-delay: 1s; opacity: 0.3; }

@keyframes ring-pulse {
  0%, 100% { transform: scale(1); opacity: 0.4; }
  50% { transform: scale(1.04); opacity: 0.7; }
}

#breathing-circle {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 35%,
    rgba(0, 229, 204, 0.35) 0%,
    rgba(0, 206, 209, 0.20) 40%,
    rgba(124, 77, 255, 0.12) 70%,
    rgba(3, 8, 15, 0.4) 100%
  );
  border: 1.5px solid rgba(0, 206, 209, 0.4);
  box-shadow: 0 0 30px rgba(0,206,209,0.25), inset 0 0 30px rgba(0,229,204,0.08);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  z-index: 2;
  cursor: default;
}

#breathing-circle .circle-phase {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--breath-mint);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
#breathing-circle .circle-timer {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
  margin-top: 0.2rem;
}
#breathing-circle .circle-label {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 0.25rem;
}

#breathing-circle.inhale {
  transform: scale(1.35);
  box-shadow: 0 0 60px rgba(0,229,204,0.45), inset 0 0 40px rgba(0,229,204,0.12);
  border-color: rgba(0, 229, 204, 0.7);
}
#breathing-circle.hold-in {
  transform: scale(1.35);
  box-shadow: 0 0 50px rgba(255,179,0,0.35), inset 0 0 30px rgba(255,179,0,0.08);
  border-color: rgba(255,179,0,0.6);
}
#breathing-circle.exhale {
  transform: scale(0.8);
  box-shadow: 0 0 20px rgba(124,77,255,0.25), inset 0 0 20px rgba(124,77,255,0.05);
  border-color: rgba(124,77,255,0.45);
}
#breathing-circle.hold-out {
  transform: scale(0.8);
  box-shadow: 0 0 15px rgba(0,206,209,0.15), inset 0 0 10px rgba(0,206,209,0.03);
  border-color: rgba(0,206,209,0.25);
}

/* Practice controls */
.practice-controls {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 2rem;
  max-width: 560px;
  margin: 0 auto;
  width: 100%;
}

.control-group {
  margin-bottom: 1.25rem;
}
.control-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
  display: block;
}
.control-select {
  width: 100%;
  padding: 0.6rem 0.9rem;
  background: var(--bg-mid);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.93rem;
  cursor: pointer;
  transition: border-color 0.2s;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%237A90B0'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.9rem center;
}
.control-select:focus { outline: none; border-color: var(--breath-teal); }

.btn-row {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.5rem;
}
.btn {
  flex: 1;
  padding: 0.7rem 1rem;
  border-radius: 7px;
  font-family: var(--font-display);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--breath-teal), var(--breath-cyan));
  color: #03080f;
}
.btn-primary:hover { box-shadow: var(--glow-teal); transform: translateY(-1px); }
.btn-secondary {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
}
.btn-secondary:hover { border-color: var(--breath-teal); color: var(--breath-mint); }

.session-stats {
  display: flex;
  gap: 1.5rem;
  margin-top: 1rem;
  padding: 0.75rem 0;
  border-top: 1px solid var(--border-subtle);
}
.session-stat-item {
  flex: 1;
  text-align: center;
}
.session-stat-num {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--breath-mint);
}
.session-stat-lbl {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ============================================================
   PROSE (article content)
   ============================================================ */
.prose {
  max-width: 780px;
}
.prose p {
  margin-bottom: 1.25rem;
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.85;
}
.prose p:last-child { margin-bottom: 0; }
.prose strong { color: var(--text-primary); font-weight: 600; }
.prose em { color: var(--text-muted); font-style: italic; }
.prose a { color: var(--breath-teal); text-decoration: none; border-bottom: 1px solid rgba(0,206,209,0.3); transition: all 0.2s; }
.prose a:hover { color: var(--breath-mint); border-color: var(--breath-mint); }

.prose h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
}
.prose h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--breath-mint);
  margin: 1.75rem 0 0.5rem;
}
.prose h4 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--breath-teal);
  margin: 1.25rem 0 0.4rem;
}

.prose ul, .prose ol {
  margin: 0.75rem 0 1.25rem;
  padding-left: 1.5rem;
  color: var(--text-muted);
}
.prose li {
  margin-bottom: 0.4rem;
  font-size: 0.97rem;
  line-height: 1.75;
}
.prose li strong { color: var(--text-primary); }

/* ── Blockquotes ── */
.prose blockquote {
  margin: 2rem 0;
  padding: 1.5rem 1.5rem 1.5rem 2.5rem;
  border-left: 3px solid var(--breath-mint);
  background: rgba(0, 229, 204, 0.03);
  border-radius: 0 8px 8px 0;
  font-style: italic;
  color: var(--text-muted);
}
.prose blockquote p { margin-bottom: 0.5rem; }
.prose blockquote cite {
  display: block;
  margin-top: 0.5rem;
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--breath-mint);
  opacity: 0.8;
  letter-spacing: 0.08em;
}

/* ── Code / Mono ── */
.prose code {
  font-family: var(--font-mono);
  font-size: 0.87em;
  color: var(--breath-mint);
  background: rgba(0, 229, 204, 0.06);
  border: 1px solid rgba(0, 229, 204, 0.10);
  border-radius: 4px;
  padding: 0.1em 0.45em;
}

/* ── Science term highlight ── */
.breath-term {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--breath-violet);
  background: rgba(124, 77, 255, 0.07);
  border: 1px solid rgba(124, 77, 255, 0.14);
  border-radius: 4px;
  padding: 0.1em 0.45em;
  white-space: nowrap;
}

/* ── Callout boxes ── */
.callout {
  margin: 2rem 0;
  padding: 1.25rem 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--border-subtle);
  position: relative;
  overflow: hidden;
}
.callout::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
}
.callout-teal   { background: rgba(0, 206, 209, 0.04);  border-color: rgba(0, 206, 209, 0.18); }
.callout-teal::before { background: var(--breath-teal); }
.callout-violet { background: rgba(124, 77, 255, 0.04); border-color: rgba(124, 77, 255, 0.18); }
.callout-violet::before { background: var(--breath-violet); }
.callout-amber  { background: rgba(255, 179, 0, 0.04);  border-color: rgba(255, 179, 0, 0.18); }
.callout-amber::before { background: var(--breath-amber); }
.callout-mint   { background: rgba(0, 229, 204, 0.04);  border-color: rgba(0, 229, 204, 0.18); }
.callout-mint::before { background: var(--breath-mint); }
.callout-warn   { background: rgba(255,100,50,0.04);    border-color: rgba(255,100,50,0.18); }
.callout-warn::before { background: #ff6432; }

.callout-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--breath-teal);
  margin-bottom: 0.6rem;
}
.callout-violet .callout-title { color: var(--breath-violet); }
.callout-amber  .callout-title { color: var(--breath-amber); }
.callout-mint   .callout-title { color: var(--breath-mint); }
.callout-warn   .callout-title { color: #ff6432; }

.callout p { font-size: 0.93rem; color: var(--text-muted); margin: 0; line-height: 1.7; }
.callout p strong { color: var(--text-primary); }

/* ── Key findings box ── */
.finding-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 2rem;
  margin: 2rem 0;
}
.finding-box h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--breath-mint);
  margin-bottom: 1rem;
}
.finding-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  list-style: none;
  padding: 0;
}
.finding-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.6;
}
.finding-list li::before {
  content: '▸';
  color: var(--breath-teal);
  flex-shrink: 0;
  margin-top: 0.1rem;
  font-size: 0.8rem;
}

/* ── Timeline ── */
.timeline {
  position: relative;
  padding-left: 2rem;
  margin: 2rem 0;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5rem;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--breath-teal), transparent);
  opacity: 0.4;
}
.timeline-item {
  position: relative;
  margin-bottom: 1.75rem;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.4rem;
  top: 0.35rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--breath-teal);
  box-shadow: 0 0 8px rgba(0, 206, 209, 0.6);
}
.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--breath-teal);
  letter-spacing: 0.1em;
  margin-bottom: 0.25rem;
}
.timeline-content {
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.65;
}
.timeline-content strong { color: var(--text-primary); }

/* ── Study card ── */
.study-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  transition: border-color 0.3s;
}
.study-card:hover { border-color: rgba(0,206,209,0.22); }
.study-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--breath-teal);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.study-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}
.study-finding {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}
.study-meta {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  letter-spacing: 0.06em;
}

/* ── References ── */
.ref-section { margin-bottom: 3rem; }
.ref-section-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--breath-mint);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.ref-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.ref-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  transition: border-color 0.2s;
}
.ref-item:hover { border-color: rgba(0, 206, 209, 0.22); }
.ref-authors {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.04em;
  margin-bottom: 0.25rem;
}
.ref-title {
  font-family: var(--font-body);
  font-size: 0.93rem;
  color: var(--text-primary);
  font-weight: 500;
  margin-bottom: 0.25rem;
  font-style: italic;
}
.ref-meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--breath-teal);
  letter-spacing: 0.04em;
}
.ref-link {
  color: var(--breath-teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(0,206,209,0.3);
  transition: color 0.2s;
}
.ref-link:hover { color: var(--breath-mint); }

/* ── Wave separator ── */
.wave-sep {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--breath-teal), transparent);
  margin: 3rem 0;
  opacity: 0.18;
}

/* ── Reveal animation ── */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s ease-out, transform 0.7s ease-out;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes float-breathe {
  0%, 100% { transform: translateY(0) scale(1); }
  33%       { transform: translateY(-8px) scale(1.04); }
  66%       { transform: translateY(-4px) scale(1.02); }
}
@keyframes pulse-breathe {
  0%, 100% { filter: brightness(1) drop-shadow(0 0 8px rgba(0,229,204,0.4)); }
  50%       { filter: brightness(1.2) drop-shadow(0 0 20px rgba(0,229,204,0.7)); }
}
@keyframes pulse-amber {
  0%, 100% { box-shadow: 0 0 8px rgba(255,179,0,0.2); }
  50%       { box-shadow: 0 0 20px rgba(255,179,0,0.4); }
}

/* ── Sound toggle ── */
.sound-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  margin-top: 0.5rem;
}
.sound-toggle input[type="checkbox"] {
  width: 36px;
  height: 20px;
  appearance: none;
  background: var(--bg-mid);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  position: relative;
  cursor: pointer;
  transition: background 0.2s;
}
.sound-toggle input[type="checkbox"]:checked { background: var(--breath-teal); border-color: var(--breath-teal); }
.sound-toggle input[type="checkbox"]::after {
  content: '';
  position: absolute;
  width: 14px;
  height: 14px;
  background: #fff;
  border-radius: 50%;
  top: 2px;
  left: 2px;
  transition: left 0.2s;
}
.sound-toggle input[type="checkbox"]:checked::after { left: 18px; }
.sound-toggle span {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Anatomy SVG colors */
.svg-lung { fill: rgba(0,206,209,0.15); stroke: var(--breath-teal); stroke-width: 1.5; }
.svg-airway { fill: none; stroke: var(--breath-aqua); stroke-width: 2; }
.svg-diaphragm { fill: none; stroke: var(--breath-amber); stroke-width: 2.5; stroke-dasharray: none; }
.svg-alveoli { fill: rgba(0,229,204,0.12); stroke: var(--breath-mint); stroke-width: 1; }
.svg-nerve { fill: none; stroke: var(--breath-violet); stroke-width: 1.5; stroke-dasharray: 4 3; }
.svg-arrow { fill: var(--breath-teal); }
.svg-label { font-family: 'JetBrains Mono', monospace; font-size: 11px; fill: var(--text-muted); }
.svg-label-primary { fill: var(--breath-teal); font-weight: 600; }
.svg-heart { fill: rgba(124,77,255,0.2); stroke: var(--breath-violet); stroke-width: 1.5; }
.svg-blood-o2  { fill: none; stroke: #ef5350; stroke-width: 2; }
.svg-blood-co2 { fill: none; stroke: #5c6bc0; stroke-width: 2; }
.svg-bg { fill: var(--bg-card); }
.svg-grid { stroke: rgba(0,206,209,0.07); stroke-width: 0.5; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .card-grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-nav-cols { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 680px) {
  .hero { padding: 4rem 0 3rem; }
  .hero-title { font-size: 2rem; }
  .hero-subtitle { font-size: 1rem; }
  .card-grid, .card-grid-2, .card-grid-3 { grid-template-columns: 1fr; }
  .nav-cards { grid-template-columns: 1fr; }
  .mobile-back-btn { display: block; }
  .hamburger { display: flex; }
  .breathe-nav { display: none; }
  .site-logo .logo-sub { display: none; }
  .footer-nav-cols { grid-template-columns: 1fr 1fr; }
  .page-header h1 { font-size: 1.75rem; }
  .prose h2 { font-size: 1.25rem; }
  .breathing-circle-outer { width: 220px; height: 220px; }
  #breathing-circle { width: 150px; height: 150px; }
  .btn-row { flex-direction: column; }
}

@media (max-width: 480px) {
  .footer-nav-cols { grid-template-columns: 1fr; }
  .stat-number { font-size: 2rem; }
  .technique-badges { display: none; }
  #breathing-circle .circle-timer { font-size: 1.6rem; }
}

.nav-link { padding: 8px 10px; font-size: 0.76rem; white-space: nowrap; }