/* ==========================================================================
   INTERWOVEN FUTURES — DESIGN SYSTEM & STYLES
   Sustainability, Systems Biology, and Health Intelligence
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS VARIABLES & THEME TOKENS
   -------------------------------------------------------------------------- */
:root {
  /* Brand Palette */
  --color-navy: #172033;
  --color-navy-dark: #0f1624;
  --color-navy-light: #222e47;
  --color-navy-rgb: 23, 32, 51;

  --color-blue: #5B8DB8;
  --color-blue-light: #7da5c6;
  --color-blue-dark: #43729c;
  --color-blue-subtle: rgba(91, 141, 184, 0.12);

  --color-sage: #6BAA75;
  --color-sage-light: #8bc094;
  --color-sage-dark: #528e5c;
  --color-sage-subtle: rgba(107, 170, 117, 0.14);

  --color-terracotta: #D97757;
  --color-terracotta-light: #e49277;
  --color-terracotta-dark: #bf5d3d;
  --color-terracotta-subtle: rgba(217, 119, 87, 0.12);

  --color-sand: #F8F1E3;
  --color-sand-light: #fcf9f2;
  --color-sand-dark: #ede2cd;

  --color-white: #FFFFFF;
  --color-text-main: #172033;
  --color-text-muted: #566479;
  --color-text-light: #e2e8f0;
  --color-border: #e3d9c8;
  --color-border-subtle: rgba(23, 32, 51, 0.08);

  /* Typography */
  --font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Space Grotesk', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Elevation & Shadows */
  --shadow-sm: 0 2px 4px rgba(23, 32, 51, 0.04), 0 1px 2px rgba(23, 32, 51, 0.06);
  --shadow-md: 0 6px 16px rgba(23, 32, 51, 0.08), 0 2px 6px rgba(23, 32, 51, 0.04);
  --shadow-lg: 0 14px 28px rgba(23, 32, 51, 0.12), 0 6px 12px rgba(23, 32, 51, 0.06);
  --shadow-glow: 0 0 30px rgba(91, 141, 184, 0.25);

  /* Radii & Layout */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-pill: 9999px;
  --container-max: 1200px;
  --header-height: 80px;

  /* Transitions */
  --transition-fast: 180ms ease;
  --transition-normal: 280ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 450ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* --------------------------------------------------------------------------
   2. RESET & BASE ELEMENTS
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-sand-light);
  color: var(--color-text-main);
  line-height: 1.65;
  font-size: 1rem;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button, input {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* Screen reader only utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Accessibility skip link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--color-navy);
  color: var(--color-sand);
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  font-weight: 600;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 20px;
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section-padding {
  padding-top: 100px;
  padding-bottom: 100px;
}

/* Section Header Typography */
.section-header {
  margin-bottom: 56px;
  max-width: 760px;
}

.section-header.text-center {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.section-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-terracotta);
  background-color: var(--color-terracotta-subtle);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  margin-bottom: 16px;
}

.section-eyebrow.eyebrow-light {
  color: var(--color-sand);
  background-color: rgba(248, 241, 227, 0.12);
}

.section-title {
  font-size: clamp(1.85rem, 3.2vw, 2.6rem);
  font-weight: 800;
  line-height: 1.22;
  color: var(--color-navy);
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}

.section-title.text-white {
  color: var(--color-white);
}

.section-subtitle {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  color: var(--color-blue-light);
  font-weight: 500;
  line-height: 1.5;
}

.section-lead {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   3. BUTTONS
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.95rem;
  transition: all var(--transition-normal);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-navy-light) 100%);
  color: var(--color-sand);
  box-shadow: 0 4px 14px rgba(23, 32, 51, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-navy-light) 0%, var(--color-blue-dark) 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(23, 32, 51, 0.25);
  color: var(--color-white);
}

.btn-primary .btn-icon {
  transition: transform var(--transition-fast);
}

.btn-primary:hover .btn-icon {
  transform: translateX(4px);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-navy);
  border: 1.5px solid var(--color-navy);
}

.btn-outline:hover {
  background-color: var(--color-navy);
  color: var(--color-sand);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(23, 32, 51, 0.15);
}

/* --------------------------------------------------------------------------
   4. STICKY HEADER & NAVIGATION
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(248, 241, 227, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(23, 32, 51, 0.08);
  z-index: 1000;
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal), height var(--transition-normal);
}

.site-header.scrolled {
  background-color: rgba(248, 241, 227, 0.96);
  box-shadow: var(--shadow-sm);
  height: 70px;
}

.header-container {
  max-width: var(--container-max);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-logo {
  height: 38px;
  width: auto;
  transition: transform var(--transition-fast);
}

.brand-link:hover .brand-logo {
  transform: scale(1.02);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--color-navy);
  border-radius: var(--radius-pill);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link:hover {
  color: var(--color-terracotta);
  background-color: rgba(217, 119, 87, 0.08);
}

.nav-link.active {
  color: var(--color-navy);
  background-color: rgba(91, 141, 184, 0.15);
}

/* Mobile Menu Toggle Button */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 44px;
  height: 44px;
  padding: 10px;
  border-radius: var(--radius-sm);
  background-color: transparent;
  z-index: 1100;
}

.menu-toggle:focus-visible {
  outline: 2px solid var(--color-terracotta);
}

.hamburger-bar {
  display: block;
  width: 100%;
  height: 2.5px;
  background-color: var(--color-navy);
  border-radius: 2px;
  transition: transform var(--transition-normal), opacity var(--transition-fast), background-color var(--transition-fast);
}

.menu-toggle.is-active .hamburger-bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.menu-toggle.is-active .hamburger-bar:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-active .hamburger-bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   5. HERO SECTION
   -------------------------------------------------------------------------- */
.hero-section {
  position: relative;
  padding: 80px 0 110px 0;
  background: radial-gradient(circle at 80% 20%, rgba(91, 141, 184, 0.18) 0%, rgba(248, 241, 227, 0) 60%),
              radial-gradient(circle at 10% 80%, rgba(107, 170, 117, 0.15) 0%, rgba(248, 241, 227, 0) 50%);
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(80px);
  z-index: 0;
}

.hero-glow-1 {
  width: 420px;
  height: 420px;
  background: rgba(91, 141, 184, 0.2);
  top: -80px;
  right: -60px;
}

.hero-glow-2 {
  width: 350px;
  height: 350px;
  background: rgba(217, 119, 87, 0.15);
  bottom: -60px;
  left: -80px;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 50px;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 640px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-navy);
  background-color: var(--color-sand-dark);
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  margin-bottom: 24px;
  border: 1px solid var(--color-border);
}

.eyebrow-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-terracotta);
  box-shadow: 0 0 8px var(--color-terracotta);
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.4); opacity: 0.7; }
}

.hero-title {
  font-size: clamp(2.3rem, 4.4vw, 3.6rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--color-navy);
  margin-bottom: 24px;
}

.highlight-text {
  color: var(--color-terracotta);
  position: relative;
  display: inline-block;
}

.highlight-text::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 4px;
  width: 100%;
  height: 8px;
  background-color: rgba(217, 119, 87, 0.18);
  border-radius: 4px;
  z-index: -1;
}

.hero-desc {
  font-size: 1.1875rem;
  line-height: 1.7;
  color: var(--color-text-muted);
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

/* Hero Interactive Visual Orbit */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.system-orb-container {
  position: relative;
  width: 360px;
  height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.orb-ring {
  position: absolute;
  border-radius: 50%;
  border: 1.5px dashed var(--color-blue);
  opacity: 0.4;
}

.ring-1 {
  width: 100%;
  height: 100%;
  animation: spinOrb 35s linear infinite;
  border-color: var(--color-blue);
}

.ring-2 {
  width: 78%;
  height: 78%;
  animation: spinOrbReverse 25s linear infinite;
  border-color: var(--color-sage);
  border-style: solid;
  border-width: 1px;
  opacity: 0.5;
}

.ring-3 {
  width: 56%;
  height: 56%;
  animation: spinOrb 18s linear infinite;
  border-color: var(--color-terracotta);
  opacity: 0.4;
}

@keyframes spinOrb {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes spinOrbReverse {
  from { transform: rotate(360deg); }
  to { transform: rotate(0deg); }
}

.orb-center {
  position: relative;
  z-index: 2;
  border-radius: 50%;
  padding: 18px;
  background-color: var(--color-sand-light);
  box-shadow: 0 10px 30px rgba(23, 32, 51, 0.15), 0 0 20px rgba(91, 141, 184, 0.2);
  transition: transform var(--transition-normal);
}

.orb-center:hover {
  transform: scale(1.08);
}

.floating-badge {
  position: absolute;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  background: var(--color-white);
  box-shadow: var(--shadow-md);
  z-index: 3;
  transition: transform var(--transition-normal);
}

.floating-badge:hover {
  transform: translateY(-4px);
}

.badge-strategy {
  top: 15px;
  left: 20px;
  color: var(--color-terracotta);
  border-left: 3px solid var(--color-terracotta);
}

.badge-biology {
  top: 30px;
  right: 15px;
  color: var(--color-sage-dark);
  border-left: 3px solid var(--color-sage);
}

.badge-ai {
  bottom: 25px;
  right: 25px;
  color: var(--color-blue-dark);
  border-left: 3px solid var(--color-blue);
}

.badge-health {
  bottom: 20px;
  left: 25px;
  color: var(--color-navy);
  border-left: 3px solid var(--color-navy);
}

/* --------------------------------------------------------------------------
   6. PRINCIPLES BAND
   -------------------------------------------------------------------------- */
.principles-band {
  background-color: var(--color-navy);
  color: var(--color-sand);
  padding: 24px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.principles-container {
  display: flex;
  justify-content: center;
  align-items: center;
}

.principles-content {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 18px 24px;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.principle-item {
  color: var(--color-sand);
  transition: color var(--transition-fast);
}

.principle-item:hover {
  color: var(--color-sage-light);
}

.principle-divider {
  color: var(--color-terracotta);
  font-size: 0.75rem;
}

/* --------------------------------------------------------------------------
   7. FIELDS SECTION
   -------------------------------------------------------------------------- */
.fields-section {
  background-color: var(--color-sand-light);
}

.fields-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.field-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  position: relative;
}

.field-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-blue);
}

.field-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.field-number {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-blue);
  background: var(--color-blue-subtle);
  width: 52px;
  height: 52px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.field-icon-wrapper {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.field-icon-org {
  background-color: var(--color-terracotta-subtle);
  color: var(--color-terracotta);
}

.field-icon-bio {
  background-color: var(--color-sage-subtle);
  color: var(--color-sage-dark);
}

.field-icon-ai {
  background-color: var(--color-blue-subtle);
  color: var(--color-blue-dark);
}

.field-icon-inn {
  background-color: rgba(23, 32, 51, 0.08);
  color: var(--color-navy);
}

.field-title {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--color-navy);
  margin-bottom: 16px;
  line-height: 1.3;
}

.field-description {
  color: var(--color-text-muted);
  font-size: 0.985rem;
  line-height: 1.65;
  margin-bottom: 28px;
  flex-grow: 1;
}

.field-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.topic-tag {
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  background-color: var(--color-sand);
  color: var(--color-navy);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.field-card:hover .topic-tag {
  background-color: var(--color-sand-dark);
}

/* --------------------------------------------------------------------------
   8. METHOD SECTION (DARK THEME)
   -------------------------------------------------------------------------- */
.method-section.dark-theme {
  background: linear-gradient(180deg, var(--color-navy-dark) 0%, var(--color-navy) 100%);
  color: var(--color-sand);
  position: relative;
  overflow: hidden;
}

.method-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 10%;
  right: 10%;
  height: 1px;
  background: radial-gradient(circle, rgba(91, 141, 184, 0.6) 0%, rgba(91, 141, 184, 0) 100%);
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}

.method-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
  backdrop-filter: blur(6px);
}

.method-card:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-blue);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

.method-step-badge {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-terracotta);
  margin-bottom: 20px;
  display: inline-block;
}

.method-step-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 14px;
}

.method-step-desc {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.6;
  opacity: 0.9;
  flex-grow: 1;
}

.method-indicator {
  height: 3px;
  background: linear-gradient(90deg, var(--color-blue), var(--color-sage));
  border-radius: 2px;
  margin-top: 24px;
  width: 36px;
  transition: width var(--transition-normal);
}

.method-card:hover .method-indicator {
  width: 100%;
}

/* --------------------------------------------------------------------------
   9. ACADEMICS SECTION
   -------------------------------------------------------------------------- */
.academics-section {
  background-color: var(--color-sand);
}

.academics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-bottom: 48px;
}

.academic-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
}

.academic-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-sage);
}

.academic-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 18px;
}

.academic-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-blue) 100%);
  color: var(--color-sand);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.academic-meta {
  flex-grow: 1;
}

.academic-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-navy);
  line-height: 1.25;
  margin-bottom: 4px;
}

.academic-inst {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

.academic-focus {
  margin-bottom: 16px;
}

.focus-pill {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-navy);
  background-color: var(--color-sand);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

.academic-bio {
  font-size: 0.9125rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 24px;
  flex-grow: 1;
}

.academic-contact-box {
  background-color: var(--color-sand-light);
  border-top: 1px solid var(--color-border);
  padding-top: 16px;
  margin-top: auto;
}

.contact-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-terracotta);
  font-weight: 700;
  margin-bottom: 4px;
}

.contact-email {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-navy);
  word-break: break-all;
  transition: color var(--transition-fast);
}

.contact-email:hover {
  color: var(--color-blue);
  text-decoration: underline;
}

/* Independence Note Card */
.independence-note-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-terracotta);
  border-radius: var(--radius-md);
  padding: 24px 30px;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  box-shadow: var(--shadow-sm);
}

.independence-note-icon {
  color: var(--color-terracotta);
  flex-shrink: 0;
  margin-top: 2px;
}

.independence-note-body {
  font-size: 0.9125rem;
  line-height: 1.6;
  color: var(--color-text-muted);
}

.independence-note-title {
  font-size: 1rem;
  font-weight: 800;
  color: var(--color-navy);
  margin-bottom: 6px;
}

.independence-note-body p + p {
  margin-top: 6px;
}

/* --------------------------------------------------------------------------
   10. LEARNING LIBRARY SECTION
   -------------------------------------------------------------------------- */
.library-section {
  background-color: var(--color-sand-light);
}

.library-search-container {
  margin-bottom: 36px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.search-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 20px;
  color: var(--color-text-muted);
  pointer-events: none;
}

.library-search-input {
  width: 100%;
  padding: 18px 52px 18px 54px;
  background-color: var(--color-white);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-size: 1.05rem;
  color: var(--color-navy);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.library-search-input:focus {
  outline: none;
  border-color: var(--color-blue);
  box-shadow: 0 0 0 4px rgba(91, 141, 184, 0.2);
}

.clear-search-btn {
  position: absolute;
  right: 18px;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--color-text-muted);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.clear-search-btn:hover {
  background-color: var(--color-sand);
  color: var(--color-navy);
}

.search-counter {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  padding-left: 16px;
}

.library-items {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.library-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.library-card:hover {
  border-color: var(--color-blue-light);
  box-shadow: var(--shadow-md);
}

.library-card[open] {
  border-color: var(--color-blue);
  box-shadow: var(--shadow-md);
}

.library-summary {
  padding: 22px 28px;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-navy);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  user-select: none;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.library-summary::-webkit-details-marker {
  display: none;
}

.library-summary:hover {
  color: var(--color-terracotta);
  background-color: rgba(248, 241, 227, 0.5);
}

.summary-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-sand);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform var(--transition-normal), background-color var(--transition-fast);
  position: relative;
}

.summary-icon::before,
.summary-icon::after {
  content: "";
  position: absolute;
  background-color: var(--color-navy);
  border-radius: 1px;
  transition: transform var(--transition-normal);
}

.summary-icon::before {
  width: 12px;
  height: 2px;
}

.summary-icon::after {
  width: 2px;
  height: 12px;
}

.library-card[open] .summary-icon {
  background-color: var(--color-blue);
}

.library-card[open] .summary-icon::before,
.library-card[open] .summary-icon::after {
  background-color: var(--color-white);
}

.library-card[open] .summary-icon::after {
  transform: rotate(90deg);
  opacity: 0;
}

.library-content {
  padding: 0 28px 26px 28px;
  color: var(--color-text-muted);
  font-size: 0.985rem;
  line-height: 1.7;
  border-top: 1px solid var(--color-border-subtle);
  padding-top: 18px;
  animation: slideDown 250ms ease-out;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.library-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.library-tags .tag {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background-color: var(--color-sand);
  color: var(--color-navy);
  border: 1px solid var(--color-border);
}

/* Empty State */
.library-empty-state {
  text-align: center;
  padding: 60px 24px;
  background-color: var(--color-white);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-lg);
  margin-top: 20px;
}

.empty-state-icon {
  color: var(--color-terracotta);
  margin-bottom: 16px;
  display: flex;
  justify-content: center;
}

.empty-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-navy);
  margin-bottom: 8px;
}

.empty-desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  max-width: 480px;
  margin: 0 auto;
}

/* --------------------------------------------------------------------------
   11. ABOUT SECTION
   -------------------------------------------------------------------------- */
.about-section {
  background-color: var(--color-sand);
}

.about-layout {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: start;
}

.about-text-body {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--color-text-muted);
}

.about-text-body p + p {
  margin-top: 20px;
}

.about-text-body strong {
  color: var(--color-navy);
}

.about-disclaimer-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow-sm);
}

.disclaimer-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-terracotta);
  background-color: var(--color-terracotta-subtle);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  margin-bottom: 16px;
}

.disclaimer-heading {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-navy);
  line-height: 1.35;
  margin-bottom: 14px;
}

.disclaimer-text {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.disclaimer-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 16px;
  margin-bottom: 20px;
}

.disclaimer-list li {
  font-size: 0.9125rem;
  font-weight: 600;
  color: var(--color-navy);
  display: flex;
  align-items: center;
  gap: 8px;
}

.bullet-x {
  color: var(--color-terracotta);
  font-weight: 800;
  font-size: 0.8rem;
}

.disclaimer-footnote {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  line-height: 1.55;
  border-top: 1px solid var(--color-border-subtle);
  padding-top: 16px;
}

/* --------------------------------------------------------------------------
   12. FOOTER
   -------------------------------------------------------------------------- */
.site-footer {
  background-color: var(--color-navy);
  color: var(--color-sand);
  padding-top: 70px;
  padding-bottom: 40px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1.2fr;
  gap: 48px;
  padding-bottom: 50px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand-col {
  max-width: 420px;
}

.footer-logo {
  filter: brightness(0) invert(1);
  height: 34px;
  width: auto;
  margin-bottom: 18px;
}

.footer-tagline {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  opacity: 0.85;
  line-height: 1.6;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 20px;
  letter-spacing: -0.01em;
}

.footer-links-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links-list a {
  font-size: 0.9125rem;
  color: var(--color-text-light);
  opacity: 0.8;
  transition: all var(--transition-fast);
}

.footer-links-list a:hover {
  opacity: 1;
  color: var(--color-terracotta-light);
  padding-left: 4px;
}

.footer-pill-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-pill-list li {
  font-size: 0.875rem;
  color: var(--color-text-light);
  opacity: 0.75;
}

.footer-bottom {
  padding-top: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.84rem;
  color: var(--color-text-light);
  opacity: 0.65;
}

/* --------------------------------------------------------------------------
   13. BACK TO TOP BUTTON
   -------------------------------------------------------------------------- */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: var(--color-navy);
  color: var(--color-sand);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  border: 1.5px solid rgba(255, 255, 255, 0.15);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all var(--transition-normal);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background-color: var(--color-terracotta);
  color: var(--color-white);
  transform: translateY(-4px);
}

/* --------------------------------------------------------------------------
   14. SCROLL REVEAL ANIMATIONS
   -------------------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.65s cubic-bezier(0.16, 1, 0.3, 1), transform 0.65s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   15. RESPONSIVE MEDIA QUERIES
   -------------------------------------------------------------------------- */

/* Tablet & Smaller Desktops */
@media (max-width: 950px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 40px;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
    margin-bottom: 10px;
  }

  .system-orb-container {
    width: 280px;
    height: 280px;
  }

  .fields-grid {
    grid-template-columns: 1fr;
  }

  .method-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .academics-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-layout {
    grid-template-columns: 1fr;
  }

  .footer-top {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand-col {
    grid-column: span 2;
    max-width: 100%;
  }
}

/* Mobile Devices */
@media (max-width: 650px) {
  :root {
    --header-height: 70px;
  }

  .section-padding {
    padding-top: 70px;
    padding-bottom: 70px;
  }

  .menu-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: var(--color-sand-light);
    padding: 36px 24px;
    transform: translateX(100%);
    transition: transform var(--transition-smooth);
    border-top: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    overflow-y: auto;
  }

  .main-nav.is-open {
    transform: translateX(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .nav-link {
    padding: 14px 20px;
    font-size: 1.15rem;
    border-radius: var(--radius-md);
  }

  .method-grid {
    grid-template-columns: 1fr;
  }

  .academics-grid {
    grid-template-columns: 1fr;
  }

  .field-card {
    padding: 28px 22px;
  }

  .disclaimer-list {
    grid-template-columns: 1fr;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .footer-brand-col {
    grid-column: span 1;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 10px;
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .principles-content {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .principle-divider {
    display: none;
  }
}

/* Reduced Motion Preferences */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}