/* ═══════════════════════════════════════════════════════════
   SENSORY RECEPTORS — STUDY GUIDE
   Palette: Indigo Ink  |  Fonts: Cormorant Garamond + Manrope
   ═══════════════════════════════════════════════════════════ */

/* ── TOKENS ── */
:root {
  --ink-deep:    #1B0A3C;
  --ink-mid:     #3D1E7C;
  --ink-light:   #7B68EE;
  --ink-pale:    #E8E0F0;
  --ink-ghost:   #F4F1FA;
  --gold:        #E6C07B;
  --orange:      #E05A2B;
  --blue:        #4A90D9;
  --green:       #4CAF50;
  --white:       #FFFFFF;
  --text-dark:   #1B0A3C;
  --text-mid:    #4A3870;
  --text-light:  #E8E0F0;
  --text-muted:  #9B8EC4;

  --font-display: 'Cormorant Garamond', Georgia, serif;
  --font-body:    'Manrope', sans-serif;

  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  32px;

  --shadow-sm:  0 2px 8px rgba(27,10,60,0.08);
  --shadow-md:  0 8px 32px rgba(27,10,60,0.14);
  --shadow-lg:  0 20px 60px rgba(27,10,60,0.22);

  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  color: var(--text-dark);
  background: var(--ink-ghost);
  line-height: 1.7;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ── PROGRESS BAR ── */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--ink-light), var(--gold));
  z-index: 1000;
  transition: width 0.1s linear;
}

/* ── CONTAINER ── */
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ── NAV ── */
.nav {
  position: fixed;
  top: 3px; left: 0; right: 0;
  z-index: 900;
  background: rgba(27, 10, 60, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(123, 104, 238, 0.2);
  transition: var(--transition);
}
.nav.scrolled {
  background: rgba(27, 10, 60, 0.98);
  box-shadow: var(--shadow-md);
}
.nav-inner {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}
.nav-chapter {
  font-family: var(--font-body);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  background: rgba(123, 104, 238, 0.15);
  border: 1px solid rgba(123, 104, 238, 0.3);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}
.nav-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink-pale);
  letter-spacing: 0.02em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.nav-link {
  font-size: 0.78rem;
  font-weight: 500;
  color: rgba(232, 224, 240, 0.7);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  letter-spacing: 0.02em;
}
.nav-link:hover { color: var(--ink-pale); background: rgba(123, 104, 238, 0.15); }
.nav-link--cta {
  color: var(--ink-deep);
  background: var(--ink-light);
  font-weight: 600;
}
.nav-link--cta:hover { background: var(--gold); color: var(--ink-deep); }
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--ink-pale);
  border-radius: 2px;
  transition: var(--transition);
}

/* ── MOBILE MENU ── */
.mobile-menu {
  position: fixed;
  top: 63px; left: 0; right: 0;
  background: var(--ink-deep);
  border-bottom: 1px solid rgba(123, 104, 238, 0.2);
  z-index: 850;
  transform: translateY(-110%);
  transition: transform var(--transition-slow);
  padding: 1rem 0;
}
.mobile-menu.open { transform: translateY(0); }
.mobile-link {
  display: block;
  padding: 0.75rem 2rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--ink-pale);
  transition: var(--transition);
}
.mobile-link:hover { color: var(--ink-light); background: rgba(123, 104, 238, 0.1); }

/* ── HERO ── */
.hero {
  min-height: 100vh;
  background: var(--ink-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: 100px 2rem 80px;
}
.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(123, 104, 238, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(123, 104, 238, 0.06) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}
.hero-orb--1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(61, 30, 124, 0.5) 0%, transparent 70%);
  top: -200px; right: -100px;
  animation: orbFloat 8s ease-in-out infinite;
}
.hero-orb--2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(123, 104, 238, 0.25) 0%, transparent 70%);
  bottom: -100px; left: -50px;
  animation: orbFloat 10s ease-in-out infinite reverse;
}
@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(20px, -30px) scale(1.05); }
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  text-align: center;
}
.hero-eyebrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}
.hero-tag {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  border: 1px solid rgba(123, 104, 238, 0.4);
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  background: rgba(123, 104, 238, 0.08);
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(4rem, 10vw, 8rem);
  font-weight: 300;
  line-height: 0.95;
  color: var(--ink-pale);
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}
.hero-title em {
  font-style: italic;
  color: var(--ink-light);
  font-weight: 300;
}
.hero-subtitle {
  font-size: 1.1rem;
  font-weight: 300;
  color: rgba(232, 224, 240, 0.65);
  max-width: 560px;
  margin: 0 auto 3rem;
  line-height: 1.8;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 2.5rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}
.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}
.hero-stat-num {
  font-family: var(--font-display);
  font-size: 2.8rem;
  font-weight: 600;
  color: var(--gold);
  line-height: 1;
}
.hero-stat-label {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(232, 224, 240, 0.5);
}
.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--ink-light);
  color: var(--ink-deep);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.9rem 2rem;
  border-radius: 100px;
  transition: var(--transition);
}
.hero-cta:hover {
  background: var(--gold);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(230, 192, 123, 0.35);
}
.hero-scroll-hint {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: rgba(232, 224, 240, 0.35);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.hero-scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(232, 224, 240, 0.35), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.35; transform: scaleY(1); }
  50% { opacity: 0.7; transform: scaleY(1.1); }
}

/* ── OBJECTIVES BAND ── */
.objectives-band {
  background: var(--ink-mid);
  padding: 2.5rem 0;
  border-top: 1px solid rgba(123, 104, 238, 0.3);
  border-bottom: 1px solid rgba(123, 104, 238, 0.3);
}
.objectives-inner {
  display: flex;
  gap: 3rem;
  align-items: flex-start;
}
.objectives-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gold);
  white-space: nowrap;
  padding-top: 0.2rem;
  flex-shrink: 0;
}
.objectives-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}
.objectives-list li {
  font-size: 0.8rem;
  color: rgba(232, 224, 240, 0.75);
  padding-left: 1rem;
  position: relative;
  line-height: 1.5;
}
.objectives-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--ink-light);
  font-size: 0.7rem;
}

/* ── SECTIONS ── */
.section {
  padding: 6rem 0;
}
.section--dark {
  background: var(--ink-deep);
  color: var(--ink-pale);
}
.section-header {
  display: flex;
  align-items: baseline;
  gap: 1.25rem;
  margin-bottom: 3rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid rgba(27, 10, 60, 0.12);
}
.section-header--light {
  border-bottom-color: rgba(232, 224, 240, 0.15);
}
.section-number {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink-light);
  letter-spacing: 0.05em;
  opacity: 0.7;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 300;
  letter-spacing: -0.01em;
  line-height: 1.1;
  color: var(--ink-deep);
}
.section--dark .section-title { color: var(--ink-pale); }
.section-intro {
  font-size: 1.05rem;
  color: rgba(232, 224, 240, 0.75);
  margin-bottom: 2.5rem;
  max-width: 700px;
}

/* ── INTRO LAYOUT ── */
.intro-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 3rem;
  margin-bottom: 4rem;
  align-items: start;
}
.intro-text p {
  margin-bottom: 1.25rem;
  color: var(--text-mid);
  font-size: 1rem;
  line-height: 1.8;
}
.lead-paragraph {
  font-family: var(--font-display);
  font-size: 1.35rem !important;
  font-weight: 400;
  line-height: 1.6 !important;
  color: var(--ink-deep) !important;
}
.section--dark .lead-paragraph { color: var(--ink-pale) !important; }

/* ── GLOSSARY CARD ── */
.glossary-card {
  background: var(--ink-deep);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}
.glossary-header {
  background: var(--gold);
  color: var(--ink-deep);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.75rem 1.5rem;
}
.glossary-list {
  padding: 1.5rem;
}
.glossary-list dt {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink-light);
  margin-top: 1.25rem;
}
.glossary-list dt:first-child { margin-top: 0; }
.glossary-list dd {
  font-size: 0.82rem;
  color: rgba(232, 224, 240, 0.7);
  line-height: 1.6;
  margin-top: 0.25rem;
}

/* ── CONCEPT BLOCK ── */
.concept-block {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-top: 3rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(123, 104, 238, 0.1);
}
.concept-block--accent {
  background: linear-gradient(135deg, var(--ink-deep) 0%, var(--ink-mid) 100%);
  color: var(--ink-pale);
  border: none;
}
.concept-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
}
.concept-block--accent .concept-title { color: var(--ink-pale); }
.concept-block p { color: var(--text-mid); margin-bottom: 1.5rem; }
.concept-block--accent p { color: rgba(232, 224, 240, 0.8); }

/* ── EXAMPLES GRID ── */
.examples-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1.5rem;
}
.example-card {
  background: var(--ink-ghost);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  border: 1px solid rgba(123, 104, 238, 0.12);
  transition: var(--transition);
}
.example-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: rgba(123, 104, 238, 0.3);
}
.example-icon { font-size: 1.75rem; margin-bottom: 0.75rem; }
.example-card h4 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 0.5rem;
}
.example-card p { font-size: 0.83rem; color: var(--text-mid); line-height: 1.6; margin: 0; }

/* ── PULLQUOTE ── */
.pullquote-block {
  margin-top: 4rem;
  padding: 3rem 0;
  border-top: 1px solid rgba(123, 104, 238, 0.15);
}
.pullquote-line {
  width: 60px;
  height: 3px;
  background: var(--ink-light);
  margin-bottom: 2rem;
}
.pullquote {
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  font-style: italic;
  font-weight: 300;
  color: var(--ink-deep);
  line-height: 1.5;
  max-width: 800px;
  margin-bottom: 2.5rem;
}
.pullquote-concepts {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.concept-pill {
  background: var(--ink-deep);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  flex: 1;
  min-width: 260px;
}
.concept-pill strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--gold);
  margin-bottom: 0.4rem;
}
.concept-pill span {
  font-size: 0.82rem;
  color: rgba(232, 224, 240, 0.65);
  line-height: 1.6;
}

/* ── RECEPTOR TABS ── */
.receptor-tabs { margin-top: 1rem; }
.tab-buttons {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0;
}
.tab-btn {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: rgba(232, 224, 240, 0.55);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  border: 1px solid rgba(123, 104, 238, 0.2);
  border-bottom: none;
  background: rgba(123, 104, 238, 0.05);
  transition: var(--transition);
  position: relative;
  bottom: -1px;
}
.tab-btn:hover { color: var(--ink-pale); background: rgba(123, 104, 238, 0.15); }
.tab-btn.active {
  color: var(--ink-deep);
  background: var(--ink-pale);
  border-color: rgba(123, 104, 238, 0.3);
}
.tab-content {
  display: none;
  background: var(--ink-pale);
  border-radius: 0 var(--radius-md) var(--radius-md) var(--radius-md);
  border: 1px solid rgba(123, 104, 238, 0.3);
  overflow: hidden;
}
.tab-content.active { display: block; }
.tab-inner {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 0;
  min-height: 380px;
}
.tab-info {
  padding: 2.5rem;
  color: var(--ink-deep);
}
.tab-number {
  font-family: var(--font-display);
  font-size: 3.5rem;
  font-weight: 300;
  color: rgba(123, 104, 238, 0.2);
  line-height: 1;
  margin-bottom: 0.5rem;
}
.tab-info h3 {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 0.75rem;
}
.tab-info > p {
  font-size: 0.9rem;
  color: var(--text-mid);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}
.receptor-subtypes h4 {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 0.75rem;
}
.receptor-subtypes ul { list-style: none; }
.receptor-subtypes li {
  font-size: 0.82rem;
  color: var(--text-mid);
  padding: 0.3rem 0 0.3rem 1rem;
  border-left: 2px solid rgba(123, 104, 238, 0.2);
  margin-bottom: 0.3rem;
  line-height: 1.5;
}
.receptor-subtypes li strong { color: var(--ink-deep); }
.tab-diagram {
  background: var(--ink-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}
.receptor-svg { width: 100%; height: auto; }
.info-box {
  background: rgba(123, 104, 238, 0.08);
  border-left: 3px solid var(--ink-light);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 0.9rem 1.1rem;
  margin-top: 1.25rem;
  font-size: 0.82rem;
  color: var(--text-mid);
  line-height: 1.6;
}
.info-box strong { color: var(--ink-deep); }
.info-box--light {
  background: rgba(232, 224, 240, 0.08);
  border-left-color: var(--gold);
  color: rgba(232, 224, 240, 0.7);
}
.info-box--light strong { color: var(--gold); }

/* ── TWO COL LAYOUT ── */
.two-col-layout {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 3.5rem;
  align-items: start;
  margin-bottom: 3rem;
}
.two-col-layout p {
  color: var(--text-mid);
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ── STEPS LIST ── */
.steps-list {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.step {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.step-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--ink-light);
  color: var(--white);
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 0.1rem;
}
.step-content strong {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 0.2rem;
}
.step-content p {
  font-size: 0.8rem !important;
  color: var(--text-mid) !important;
  margin: 0 !important;
  line-height: 1.5 !important;
}

/* ── CHARTS ── */
.chart-container {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(123, 104, 238, 0.1);
}
.chart-container--half { max-width: 520px; }
.chart-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 1rem;
}
.chart-title--light { color: var(--ink-pale); }
.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  margin-top: 1rem;
}
.chart-legend--light .legend-item { color: rgba(232, 224, 240, 0.7); }
.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-mid);
}
.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.chart-caption {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
  font-style: italic;
  line-height: 1.5;
}
.chart-caption--light { color: rgba(232, 224, 240, 0.45); }
.chart-row { margin-top: 3rem; }
canvas { display: block; width: 100% !important; }

/* ── PACINIAN LAYOUT ── */
.pacinian-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 2.5rem;
  align-items: center;
}
.pacinian-layout p {
  color: rgba(232, 224, 240, 0.8);
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
  line-height: 1.8;
}
.feature-list { list-style: none; }
.feature-list li {
  font-size: 0.83rem;
  color: rgba(232, 224, 240, 0.7);
  padding: 0.4rem 0 0.4rem 1.25rem;
  position: relative;
  line-height: 1.5;
}
.feature-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--gold);
  font-size: 0.7rem;
  top: 0.5rem;
}
.pacinian-svg { width: 100%; height: auto; }

/* ── ADAPTATION LAYOUT ── */
.adaptation-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 3rem;
  align-items: start;
}
.adaptation-chart-wrap { }
.adaptation-info { }
.adaptation-type {
  background: rgba(232, 224, 240, 0.05);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(232, 224, 240, 0.1);
}
.adaptation-badge {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
  margin-bottom: 0.75rem;
}
.adaptation-badge--rapid { background: rgba(230, 192, 123, 0.2); color: var(--gold); }
.adaptation-badge--slow { background: rgba(74, 144, 217, 0.2); color: var(--blue); }
.adaptation-type h4 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink-pale);
  margin-bottom: 0.5rem;
}
.adaptation-type p {
  font-size: 0.83rem;
  color: rgba(232, 224, 240, 0.65);
  margin-bottom: 0.75rem;
  line-height: 1.6;
}
.adaptation-type ul { list-style: none; }
.adaptation-type li {
  font-size: 0.8rem;
  color: rgba(232, 224, 240, 0.6);
  padding: 0.25rem 0 0.25rem 1rem;
  position: relative;
}
.adaptation-type li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--ink-light);
}
.adaptation-type li strong { color: rgba(232, 224, 240, 0.85); }

/* ── FIBER CLASSIFICATION ── */
.fiber-classification { margin-top: 2rem; }
.subsection-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 1.5rem;
  letter-spacing: -0.01em;
}
.fiber-scale { }
.fiber-scale-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  margin-bottom: 0.75rem;
}
.fiber-bars {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-bottom: 1.5rem;
}
.fiber-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
  cursor: pointer;
  transition: var(--transition);
}
.fiber-bar:hover { transform: translateX(4px); }
.fiber-bar.active .fiber-bar-fill { opacity: 1; box-shadow: 0 0 12px rgba(123, 104, 238, 0.4); }
.fiber-bar-label {
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--ink-deep);
  width: 28px;
  flex-shrink: 0;
}
.fiber-bar-fill {
  height: 22px;
  border-radius: 4px;
  opacity: 0.75;
  transition: var(--transition);
}
.fiber-bar--alpha .fiber-bar-fill { width: 100%; background: linear-gradient(90deg, var(--ink-light), var(--ink-mid)); }
.fiber-bar--beta  .fiber-bar-fill { width: 78%;  background: linear-gradient(90deg, #6B5FD4, #9B8EC4); }
.fiber-bar--gamma .fiber-bar-fill { width: 55%;  background: linear-gradient(90deg, #8B7FD4, #B8B0E0); }
.fiber-bar--delta .fiber-bar-fill { width: 35%;  background: linear-gradient(90deg, var(--blue), #7BB8E8); }
.fiber-bar--c     .fiber-bar-fill { width: 15%;  background: linear-gradient(90deg, var(--orange), #F0956B); }
.fiber-bar-info {
  font-size: 0.75rem;
  color: var(--text-muted);
  white-space: nowrap;
}
.fiber-detail-panel {
  background: var(--ink-deep);
  border-radius: var(--radius-md);
  padding: 1.5rem 2rem;
  min-height: 100px;
  display: flex;
  align-items: center;
}
.fiber-detail-hint {
  font-size: 0.85rem;
  color: rgba(232, 224, 240, 0.35);
  font-style: italic;
}
.fiber-detail-content { color: var(--ink-pale); }
.fiber-detail-content h4 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--gold);
  margin-bottom: 0.5rem;
}
.fiber-detail-content p {
  font-size: 0.83rem;
  color: rgba(232, 224, 240, 0.7);
  line-height: 1.6;
}
.fiber-detail-content ul { list-style: none; margin-top: 0.5rem; }
.fiber-detail-content li {
  font-size: 0.8rem;
  color: rgba(232, 224, 240, 0.65);
  padding: 0.2rem 0 0.2rem 1rem;
  position: relative;
}
.fiber-detail-content li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--ink-light);
  font-size: 0.7rem;
}

/* ── SENSORY TABLE ── */
.sensory-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(123, 104, 238, 0.12);
}
.sensory-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.sensory-table thead {
  background: var(--ink-deep);
  color: var(--ink-pale);
}
.sensory-table th {
  padding: 0.9rem 1.25rem;
  text-align: left;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(232, 224, 240, 0.7);
}
.sensory-table td {
  padding: 0.85rem 1.25rem;
  color: var(--text-mid);
  border-bottom: 1px solid rgba(123, 104, 238, 0.08);
  line-height: 1.5;
}
.sensory-table td strong { color: var(--ink-deep); }
.row-highlight td { background: rgba(123, 104, 238, 0.04); }
.sensory-table tbody tr:last-child td { border-bottom: none; }
.sensory-table tbody tr:hover td { background: rgba(123, 104, 238, 0.07); }

/* ── SPEED CARDS ── */
.speed-comparison { margin-top: 3rem; }
.speed-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1.5rem;
}
.speed-card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  text-align: center;
  border: 1px solid rgba(123, 104, 238, 0.12);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.speed-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(123, 104, 238, 0.3);
}
.speed-icon { font-size: 2rem; margin-bottom: 0.75rem; }
.speed-val {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 0.5rem;
  line-height: 1;
}
.speed-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── SUMMATION LAYOUT ── */
.summation-layout {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 3rem;
  align-items: start;
  margin-bottom: 3rem;
}
.summation-text h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--ink-pale);
  margin-bottom: 0.5rem;
}
.summation-text p {
  font-size: 0.9rem;
  color: rgba(232, 224, 240, 0.7);
  line-height: 1.8;
}

/* ── SUMMARY BOX ── */
.summary-box {
  background: rgba(232, 224, 240, 0.05);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(232, 224, 240, 0.12);
}
.summary-box-header {
  background: var(--orange);
  color: var(--white);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.85rem 2rem;
}
.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}
.summary-item {
  padding: 2rem 1.5rem;
  border-right: 1px solid rgba(232, 224, 240, 0.08);
  text-align: center;
}
.summary-item:last-child { border-right: none; }
.summary-icon { font-size: 1.75rem; margin-bottom: 0.75rem; }
.summary-item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--gold);
  margin-bottom: 0.5rem;
}
.summary-item p {
  font-size: 0.78rem;
  color: rgba(232, 224, 240, 0.55);
  line-height: 1.5;
  margin: 0;
}

/* ── QUIZ ── */
.quiz-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}
.quiz-question {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(123, 104, 238, 0.1);
  transition: var(--transition);
}
.quiz-question.answered { border-color: rgba(123, 104, 238, 0.25); }
.quiz-q-num {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 0.5rem;
}
.quiz-q-text {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink-deep);
  margin-bottom: 1.25rem;
  line-height: 1.4;
}
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.quiz-option {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1.5px solid rgba(123, 104, 238, 0.15);
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.88rem;
  color: var(--text-mid);
  background: var(--ink-ghost);
}
.quiz-option:hover:not(.disabled) {
  border-color: var(--ink-light);
  background: rgba(123, 104, 238, 0.06);
  color: var(--ink-deep);
}
.quiz-option.selected {
  border-color: var(--ink-light);
  background: rgba(123, 104, 238, 0.1);
  color: var(--ink-deep);
}
.quiz-option.correct {
  border-color: var(--green);
  background: rgba(76, 175, 80, 0.08);
  color: #2E7D32;
}
.quiz-option.incorrect {
  border-color: var(--orange);
  background: rgba(224, 90, 43, 0.08);
  color: #C62828;
}
.quiz-option.disabled { cursor: default; }
.quiz-option-letter {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(123, 104, 238, 0.12);
  color: var(--ink-light);
  font-size: 0.72rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.quiz-option.correct .quiz-option-letter { background: var(--green); color: white; }
.quiz-option.incorrect .quiz-option-letter { background: var(--orange); color: white; }
.quiz-explanation {
  margin-top: 1rem;
  padding: 0.9rem 1.1rem;
  background: rgba(123, 104, 238, 0.06);
  border-left: 3px solid var(--ink-light);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.82rem;
  color: var(--text-mid);
  line-height: 1.6;
  display: none;
}
.quiz-explanation.visible { display: block; }
.quiz-controls {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
}
.btn {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.85rem 2rem;
  border-radius: 100px;
  transition: var(--transition);
}
.btn--primary {
  background: var(--ink-light);
  color: var(--white);
}
.btn--primary:hover {
  background: var(--ink-mid);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(123, 104, 238, 0.35);
}
.btn--secondary {
  background: transparent;
  color: var(--ink-mid);
  border: 1.5px solid var(--ink-light);
}
.btn--secondary:hover {
  background: rgba(123, 104, 238, 0.08);
  transform: translateY(-2px);
}
.quiz-result {
  background: var(--ink-deep);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  text-align: center;
  color: var(--ink-pale);
}
.quiz-result-score {
  font-family: var(--font-display);
  font-size: 4rem;
  font-weight: 300;
  color: var(--gold);
  line-height: 1;
  margin-bottom: 0.5rem;
}
.quiz-result-label {
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(232, 224, 240, 0.5);
  margin-bottom: 1rem;
}
.quiz-result-msg {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-style: italic;
  color: var(--ink-pale);
}

/* ── FOOTER ── */
.footer {
  background: var(--ink-deep);
  border-top: 1px solid rgba(123, 104, 238, 0.2);
  padding: 2.5rem 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.footer-chapter {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  background: rgba(123, 104, 238, 0.15);
  border: 1px solid rgba(123, 104, 238, 0.3);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}
.footer-title {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--ink-pale);
}
.footer-meta p {
  font-size: 0.75rem;
  color: rgba(232, 224, 240, 0.35);
  line-height: 1.6;
}

/* ── SCROLL REVEAL ── */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── RESPONSIVE ── */
@media (max-width: 1024px) {
  .intro-layout { grid-template-columns: 1fr; }
  .two-col-layout { grid-template-columns: 1fr; }
  .adaptation-layout { grid-template-columns: 1fr; }
  .summation-layout { grid-template-columns: 1fr; }
  .pacinian-layout { grid-template-columns: 1fr; }
  .tab-inner { grid-template-columns: 1fr; }
  .tab-diagram { min-height: 260px; }
  .summary-grid { grid-template-columns: repeat(2, 1fr); }
  .summary-item { border-bottom: 1px solid rgba(232, 224, 240, 0.08); }
  .summary-item:nth-child(2) { border-right: none; }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .hero-stats { gap: 1.5rem; }
  .examples-grid { grid-template-columns: 1fr; }
  .speed-cards { grid-template-columns: 1fr; }
  .summary-grid { grid-template-columns: 1fr; }
  .summary-item { border-right: none; }
  .objectives-inner { flex-direction: column; gap: 1rem; }
  .pullquote-concepts { flex-direction: column; }
  .tab-buttons { gap: 0.25rem; }
  .tab-btn { font-size: 0.7rem; padding: 0.5rem 0.75rem; }
  .section { padding: 4rem 0; }
  .hero { padding: 80px 1.5rem 60px; }
  .container { padding: 0 1.25rem; }
}
@media (max-width: 480px) {
  .hero-title { font-size: 3.5rem; }
  .hero-stats { gap: 1rem; }
  .hero-stat-num { font-size: 2rem; }
  .fiber-bar-info { display: none; }
}