/*! HTML5 Boilerplate v9.0.1 | MIT License | https://html5boilerplate.com/ */

/* ==========================================================================
   Base styles: opinionated defaults
   ========================================================================== */

html {
  color: #222;
  font-size: 1em;
  line-height: 1.4;
}

::-moz-selection {
  background: #FF3838; /* PALETTE UPDATE */
  text-shadow: none;
}

::selection {
  background: #FF3838; /* PALETTE UPDATE */
  text-shadow: none;
}

hr {
  display: block;
  height: 1px;
  border: 0;
  border-top: 1px solid #ccc;
  margin: 1em 0;
  padding: 0;
}

audio,
canvas,
iframe,
img,
svg,
video {
  vertical-align: middle;
}

fieldset {
  border: 0;
  margin: 0;
  padding: 0;
}

textarea {
  resize: vertical;
}

/* ==========================================================================
   Helper classes
   ========================================================================== */

.hidden,
[hidden] {
  display: none !important;
}

.visually-hidden {
  border: 0;
  clip: rect(0, 0, 0, 0);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  white-space: nowrap;
  width: 1px;
}

.visually-hidden.focusable:active,
.visually-hidden.focusable:focus {
  clip: auto;
  height: auto;
  margin: 0;
  overflow: visible;
  position: static;
  white-space: inherit;
  width: auto;
}

.invisible {
  visibility: hidden;
}

.clearfix::before,
.clearfix::after {
  content: "";
  display: table;
}

.clearfix::after {
  clear: both;
}

/* ==========================================================================
   Custom Properties (CSS Variables) - Modern Design System
   ========================================================================== */

:root {
  /* Primary Brand Colors - Scientific Blood Theme */
  --color-primary: #DC0000; /* PALETTE UPDATE */
  --color-primary-dark: #050E3C; /* PALETTE UPDATE */
  --color-primary-light: #FF3838; /* PALETTE UPDATE */
  --color-primary-gradient: linear-gradient(135deg, #DC0000 0%, #FF3838 100%); /* PALETTE UPDATE */

  /* Secondary Colors - Medical/Scientific */
  --color-secondary: #002455; /* PALETTE UPDATE */
  --color-secondary-dark: #050E3C; /* PALETTE UPDATE */
  --color-secondary-light: #CCFBF1;

  /* Accent Colors */
  --color-accent: #DC0000; /* PALETTE UPDATE */
  --color-accent-light: #FF3838; /* PALETTE UPDATE */

  /* Neutral Colors */
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F9FAFB;
  --color-bg-tertiary: #F3F4F6;
  --color-border: #E5E7EB;
  --color-border-light: #F3F4F6;

  /* Text Colors */
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-text-tertiary: #9CA3AF;

  /* Semantic Colors */
  --color-success: #050E3C; /* PALETTE UPDATE */
  --color-success-light: #002455; /* PALETTE UPDATE */
  --color-warning: #F59E0B;
  --color-warning-light: #FEF3C7;
  --color-info: #050E3C; /* PALETTE UPDATE */
  --color-info-light: #002455; /* PALETTE UPDATE */

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;

  /* Spacing Scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   Global Styles
   ========================================================================== */

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

body {
  font-family: var(--font-sans);
  background: linear-gradient(to bottom, #F9FAFB 0%, #FFFFFF 100%);
  color: var(--color-text-primary);
  line-height: 1.6;
  padding: var(--space-lg);
  font-size: 16px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ==========================================================================
   Skip Link (Accessibility)
   ========================================================================== */

.skip-link {
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-primary);
  color: white;
  padding: var(--space-md) var(--space-xl);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  z-index: 1000;
  transition: top var(--transition-base);
  box-shadow: var(--shadow-lg);
}

.skip-link:focus {
  top: 0;
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* ==========================================================================
   Header Styling
   ========================================================================== */

header {
  text-align: center;
  margin-bottom: var(--space-3xl);
  padding: var(--space-2xl) var(--space-md);
  animation: fadeInDown 0.6s ease-out;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

header h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  background: var(--color-primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  font-weight: 800;
  letter-spacing: -0.02em;
}

header p {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--color-text-secondary);
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto;
}

/* ==========================================================================
   Main Container
   ========================================================================== */

main {
  max-width: 1200px;
  margin: 0 auto;
  animation: fadeIn 0.8s ease-out 0.2s both;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* ==========================================================================
   Parent Selection Container - Side by Side Layout
   ========================================================================== */

.parent-selection-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

/* ==========================================================================
   Parent Selection Cards - Compact Design
   ========================================================================== */

.parent-selection {
  background: var(--color-bg-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.parent-selection::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-primary-gradient);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.parent-selection:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.parent-selection:hover::before {
  opacity: 1;
}

.parent-selection h2 {
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.parent-selection h2::before {
  content: '👤';
  font-size: 1.125rem;
}

.parent-note {
  color: var(--color-text-tertiary);
  font-size: 0.8125rem;
  margin-bottom: var(--space-lg);
  font-style: italic;
}

/* Form Elements - Compact Design */

label {
  display: block;
  margin-top: var(--space-md);
  margin-bottom: var(--space-xs);
  font-weight: 600;
  color: var(--color-text-primary);
  font-size: 0.875rem;
  letter-spacing: 0.01em;
}

select {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  border: 2px solid var(--color-border);
  font-size: 0.9375rem;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%236B7280' d='M10.293 3.293L6 7.586 1.707 3.293A1 1 0 00.293 4.707l5 5a1 1 0 001.414 0l5-5a1 1 0 10-1.414-1.414z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-sm) center;
  padding-right: var(--space-2xl);
}

select:hover {
  border-color: var(--color-primary);
}

select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

/* Calculate Button - Compact CTA */

button#calculate-btn {
  display: block;
  width: 100%;
  padding: var(--space-md) var(--space-xl);
  font-size: 1rem;
  font-weight: 700;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-xl);
  background: var(--color-primary-gradient);
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md);
  letter-spacing: 0.02em;
  text-transform: uppercase;
  position: relative;
  overflow: hidden;
}

button#calculate-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.5s;
}

button#calculate-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

button#calculate-btn:hover::before {
  left: 100%;
}

button#calculate-btn:active {
  transform: translateY(0);
  box-shadow: var(--shadow-md);
}

button#calculate-btn:focus {
  outline: none;
  box-shadow: var(--shadow-xl), 0 0 0 3px var(--color-primary-light);
}

/* ==========================================================================
   Results Section - Compact Design
   ========================================================================== */

#results {
  background: var(--color-bg-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  margin-top: var(--space-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--color-border-light);
  animation: slideUp 0.6s ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Results Header Bar - Compact */
.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--color-border);
}

#results h2 {
  color: var(--color-primary);
  font-size: 1.5rem;
  margin: 0;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

#results h2::before {
  content: '📊';
  font-size: 1.25rem;
}

/* Presentation Mode Toggle - Compact */
.presentation-toggle {
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-secondary-dark) 100%);
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.presentation-toggle:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.presentation-toggle label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
  margin: 0;
}

.presentation-toggle .toggle-label {
  color: white;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* Custom Switch Toggle - Compact */
.toggle-switch {
  position: relative;
  display: inline-block;
  width: 42px;
  height: 22px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-full);
  transition: var(--transition-base);
}

.toggle-slider::before {
  position: absolute;
  content: "";
  height: 16px;
  width: 16px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  border-radius: 50%;
  transition: var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.toggle-switch input:checked + .toggle-slider {
  background-color: var(--color-primary);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(20px);
}

.toggle-switch input:focus + .toggle-slider {
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.4);
}

/* Results Summary Card - Compact */
.results-summary {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, white 100%);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  border: 2px solid var(--color-border-light);
}

.summary-placeholder {
  text-align: center;
  color: var(--color-text-tertiary);
  font-style: italic;
  padding: var(--space-xl);
}

.summary-badges {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.summary-badge {
  background: white;
  border-radius: var(--radius-md);
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-xs);
  box-shadow: var(--shadow-sm);
  border: 2px solid var(--color-border);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.summary-badge::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  transition: opacity var(--transition-base);
}

.summary-badge:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.blood-badge::before {
  background: var(--color-primary-gradient);
}

.rh-badge::before {
  background: linear-gradient(135deg, #DC0000 0%, #FF3838 100%); /* PALETTE UPDATE */
}

.sickle-badge::before {
  background: linear-gradient(135deg, #DC0000 0%, #FF3838 100%); /* PALETTE UPDATE */
}

.badge-label {
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
  color: var(--color-text-tertiary);
}

.badge-value {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text-primary);
  font-family: var(--font-mono);
}

.badge-percent {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
}

.summary-note {
  text-align: center;
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  font-style: italic;
  margin: 0;
}

/* Results Details Text - Compact */
.results-details {
  background: var(--color-bg-tertiary);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  line-height: 1.7;
  font-size: 0.875rem;
}

.results-details strong {
  color: var(--color-primary);
  font-weight: 700;
}

/* ==========================================================================
   Punnett Squares - Compact 3-Column Grid Layout
   ========================================================================== */

#punnett-squares {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.punnett-section {
  background: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--color-border);
}

.punnett-section h3 {
  color: var(--color-secondary-dark);
  margin-bottom: var(--space-md);
  font-size: 1rem;
  font-weight: 700;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
}

.punnett-section h3::before {
  content: '🧬';
  font-size: 0.875rem;
}

.punnett-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* Punnett Table Styling - Compact */
.punnett-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: var(--space-sm) auto;
  box-shadow: var(--shadow-md);
  border-radius: var(--radius-md);
  overflow: hidden;
  font-size: 0.75rem;
}

.punnett-table th,
.punnett-table td {
  padding: var(--space-sm);
  text-align: center;
  border: 1px solid var(--color-border);
}

/* Corner cell (empty) */
.punnett-table .corner-cell {
  background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-secondary) 100%);
  color: var(--color-text-tertiary);
  font-weight: 600;
}

/* Column headers (Parent 2 alleles) */
.punnett-table .col-allele {
  background: linear-gradient(135deg, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  color: #FF3838; /* PALETTE UPDATE */
  font-weight: 700;
  font-size: 0.875rem;
  font-family: var(--font-mono);
}

/* Row headers (Parent 1 alleles) */
.punnett-table .row-allele {
  background: linear-gradient(135deg, #002455 0%, #050E3C 100%); /* PALETTE UPDATE */
  color: #FF3838; /* PALETTE UPDATE */
  font-weight: 700;
  font-size: 0.875rem;
  font-family: var(--font-mono);
}

/* Offspring cells */
.punnett-table .offspring-cell {
  background-color: white;
  min-width: 60px;
  transition: all var(--transition-base);
  position: relative;
  cursor: help;
}

.punnett-table .offspring-cell:hover {
  background-color: #FF3838; /* PALETTE UPDATE */
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
  z-index: 1;
}

/* Genotype: primary display */
.punnett-table .genotype {
  display: block;
  font-weight: 800;
  font-size: 0.9375rem;
  color: var(--color-text-primary);
  letter-spacing: 0.05em;
  font-family: var(--font-mono);
  margin-bottom: var(--space-xs);
}

/* Phenotype: secondary display */
.punnett-table .phenotype {
  display: block;
  font-size: 0.6875rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
  padding-top: var(--space-xs);
  border-top: 1px dashed var(--color-border);
  font-weight: 500;
}

/* Most likely outcome highlighting */
.punnett-table .offspring-cell.most-likely {
  background: linear-gradient(135deg, #FF3838 0%, #FF3838 100%); /* PALETTE UPDATE */
  box-shadow: inset 0 0 0 3px var(--color-primary);
  position: relative;
}

.punnett-table .offspring-cell.most-likely:hover {
  background: linear-gradient(135deg, #FF3838 0%, #DC0000 100%); /* PALETTE UPDATE */
}

/* Visual indicator badge */
.punnett-table .likelihood-indicator {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  width: 10px;
  height: 10px;
  background-color: var(--color-primary);
  border-radius: 50%;
  box-shadow: 0 0 0 2px white;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

/* Legend below table - Compact */
.punnett-legend {
  text-align: center;
  font-size: 0.6875rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-sm);
  font-style: italic;
}

.punnett-legend .legend-row,
.punnett-legend .legend-col {
  font-weight: 600;
  color: var(--color-text-primary);
}

/* Explanation block - Compact */
.punnett-explanation {
  margin-top: var(--space-md);
  padding: var(--space-md);
  background: white;
  border-left: 3px solid var(--color-secondary);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  box-shadow: var(--shadow-sm);
}

.punnett-explanation p {
  margin: 0 0 var(--space-xs) 0;
}

.punnett-explanation p:last-child {
  margin-bottom: 0;
}

.punnett-explanation ul {
  margin: var(--space-xs) 0;
  padding-left: var(--space-lg);
}

.punnett-explanation li {
  margin-bottom: var(--space-xs);
}

.punnett-explanation li:last-child {
  margin-bottom: 0;
}

.punnett-explanation .trait-note {
  margin-top: var(--space-sm);
  padding-top: var(--space-xs);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-tertiary);
  font-size: 0.6875rem;
}

/* ==========================================================================
   Inheritance Diagrams - Compact 3-Column Grid
   ========================================================================== */

#inheritance-diagrams {
  margin-top: var(--space-xl);
  padding-top: var(--space-xl);
  border-top: 2px solid var(--color-border);
}

#inheritance-diagrams h3 {
  color: var(--color-secondary-dark);
  margin-bottom: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 700;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

#inheritance-diagrams h3::before {
  content: '👨‍👩‍👧‍👦';
  font-size: 1rem;
}

.diagram-caption {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
  text-align: center;
  font-style: italic;
  line-height: 1.5;
}

#inheritance-diagrams > div:not(.diagram-section) {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.diagram-section {
  padding: var(--space-lg);
  background: linear-gradient(to bottom, var(--color-bg-secondary) 0%, white 100%);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
}

.diagram-section h4 {
  color: var(--color-primary);
  margin: 0 0 var(--space-md) 0;
  font-size: 0.875rem;
  text-align: center;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.diagram-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* Pedigree Layout - Compact */
.pedigree {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 280px;
  padding: var(--space-md);
}

.pedigree-row {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
}

.parents-row {
  gap: 60px;
  margin-bottom: var(--space-lg);
}

.children-row {
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

/* Node Styling - Compact */
.pedigree-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  animation: nodeAppear 0.5s ease-out both;
}

@keyframes nodeAppear {
  from {
    opacity: 0;
    transform: scale(0.8);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.pedigree-node:nth-child(1) { animation-delay: 0.1s; }
.pedigree-node:nth-child(2) { animation-delay: 0.2s; }
.pedigree-node:nth-child(3) { animation-delay: 0.3s; }
.pedigree-node:nth-child(4) { animation-delay: 0.4s; }

.node-circle {
  width: 70px;
  height: 70px;
  border-radius: 50%;
  background: white;
  border: 3px solid var(--color-secondary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-xs);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  cursor: help;
}

.node-circle:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-lg);
}

.parent-node .node-circle {
  background: linear-gradient(135deg, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  border-color: #050E3C; /* PALETTE UPDATE */
  border-width: 4px;
}

.child-node .node-circle {
  background: linear-gradient(135deg, #FF3838 0%, #DC0000 100%); /* PALETTE UPDATE */
  border-color: #002455; /* PALETTE UPDATE */
}

.node-label {
  font-size: 0.5625rem;
  color: rgba(255, 255, 255, 0.75); /* PALETTE UPDATE */
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 2px;
}

.node-genotype {
  font-size: 0.875rem;
  font-weight: 800;
  color: #FFFFFF; /* PALETTE UPDATE */
  margin: 2px 0;
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
}

.node-phenotype {
  font-size: 0.5625rem;
  color: rgba(255, 255, 255, 0.85); /* PALETTE UPDATE */
  line-height: 1.2;
  font-weight: 500;
}

.probability-label {
  margin-top: var(--space-xs);
  font-size: 0.625rem;
  color: #050E3C; /* PALETTE UPDATE */
  font-weight: 700;
  background: var(--color-primary-light);
  padding: 2px var(--space-xs);
  border-radius: var(--radius-full);
}

/* Connector Lines - Compact */
.pedigree-connector {
  position: relative;
  width: 100%;
  height: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.connector-horizontal,
.connector-vertical,
.connector-branch {
  background: linear-gradient(to right, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  box-shadow: var(--shadow-sm);
  border-radius: 2px;
}

.connector-horizontal {
  position: absolute;
  top: 0;
  width: 60px;
  height: 3px;
}

.connector-vertical {
  position: absolute;
  top: 0;
  width: 3px;
  height: 20px;
}

.connector-branch {
  position: absolute;
  top: 18px;
  width: 180px;
  height: 3px;
}

.connector-branch::before,
.connector-branch::after {
  content: '';
  position: absolute;
  top: 0;
  width: 3px;
  height: 22px;
  background: linear-gradient(to bottom, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  box-shadow: var(--shadow-sm);
  border-radius: 2px;
}

.connector-branch::before {
  left: 0;
}

.connector-branch::after {
  right: 0;
}

.children-row .child-node:nth-child(2)::before,
.children-row .child-node:nth-child(3)::before {
  content: '';
  position: absolute;
  top: -22px;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 22px;
  background: linear-gradient(to bottom, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  box-shadow: var(--shadow-sm);
  border-radius: 2px;
}

.children-row .child-node {
  position: relative;
}

/* ==========================================================================
   Model Assumptions Section - Compact
   ========================================================================== */

#model-assumptions {
  margin-top: var(--space-xl);
  padding: var(--space-lg);
  background: linear-gradient(135deg, var(--color-warning-light) 0%, var(--color-bg-secondary) 100%);
  border: 2px solid var(--color-warning);
  border-radius: var(--radius-lg);
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  box-shadow: var(--shadow-sm);
}

#model-assumptions h3 {
  margin: 0 0 var(--space-md) 0;
  font-size: 1rem;
  color: var(--color-warning);
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

#model-assumptions h3::before {
  content: '⚠️';
  font-size: 0.875rem;
}

#model-assumptions ul {
  margin: 0;
  padding-left: var(--space-xl);
  list-style: none;
}

#model-assumptions li {
  margin-bottom: var(--space-sm);
  position: relative;
  padding-left: var(--space-sm);
}

#model-assumptions li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--color-warning);
  font-weight: bold;
}

#model-assumptions li:last-child {
  margin-bottom: 0;
}

#model-assumptions strong {
  color: var(--color-text-primary);
  font-weight: 700;
}

/* ==========================================================================
   Presentation Mode Styles
   ========================================================================== */

/* Hide explanatory content in presentation mode */
#results.presentation-mode .punnett-explanation,
#results.presentation-mode .trait-note,
#results.presentation-mode #model-assumptions,
#results.presentation-mode .diagram-caption,
#results.presentation-mode .summary-note {
  display: none;
}

/* Main container dark theme */
#results.presentation-mode {
  background: var(--color-bg-primary); /* KEEP LIGHT MODE IN PRESENTATION */
  color: var(--color-text-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode h2::before,
#results.presentation-mode h3::before {
  filter: grayscale(0);
}

/* Results header */
#results.presentation-mode .results-header {
  border-bottom-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Summary card */
#results.presentation-mode .results-summary {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, white 100%); /* KEEP LIGHT MODE IN PRESENTATION */
  border-color: var(--color-border-light); /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Summary badges - FIXED */
#results.presentation-mode .summary-badge {
  background: white; /* KEEP LIGHT MODE IN PRESENTATION */
  border-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

#results.presentation-mode .summary-badge::before {
  opacity: 1;
}

#results.presentation-mode .badge-label {
  color: var(--color-text-tertiary) !important; /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .badge-value {
  color: var(--color-text-primary) !important; /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .badge-percent {
  background: transparent; /* KEEP LIGHT MODE IN PRESENTATION */
  color: var(--color-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Results details text */
#results.presentation-mode .results-details {
  background: var(--color-bg-tertiary); /* KEEP LIGHT MODE IN PRESENTATION */
  border-left-color: var(--color-primary);
  color: var(--color-text-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .results-details strong {
  color: var(--color-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Punnett sections */
#results.presentation-mode .punnett-section {
  background: var(--color-bg-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
  border-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-section h3 {
  color: var(--color-secondary-dark) !important; /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Punnett table */
#results.presentation-mode .punnett-table {
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

#results.presentation-mode .punnett-table th,
#results.presentation-mode .punnett-table td {
  border-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .corner-cell {
  background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-secondary) 100%); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .col-allele {
  background: linear-gradient(135deg, var(--color-info-light) 0%, white 100%); /* KEEP LIGHT MODE IN PRESENTATION */
  color: var(--color-info); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .row-allele {
  background: linear-gradient(135deg, var(--color-success-light) 0%, white 100%); /* KEEP LIGHT MODE IN PRESENTATION */
  color: var(--color-success); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .offspring-cell {
  background: white; /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .offspring-cell:hover {
  background: var(--color-warning-light); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .genotype {
  color: var(--color-text-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .phenotype {
  color: var(--color-text-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
  border-top-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-table .offspring-cell.most-likely {
  background: linear-gradient(135deg, #DC0000 0%, #FF3838 100%); /* PALETTE UPDATE */
  box-shadow: inset 0 0 0 3px var(--color-primary);
}

#results.presentation-mode .punnett-legend {
  color: var(--color-text-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .punnett-legend .legend-row,
#results.presentation-mode .punnett-legend .legend-col {
  color: var(--color-text-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Inheritance diagrams section */
#results.presentation-mode #inheritance-diagrams {
  border-top-color: var(--color-border); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .diagram-section {
  background: linear-gradient(to bottom, var(--color-bg-secondary) 0%, white 100%); /* KEEP LIGHT MODE IN PRESENTATION */
  border-color: var(--color-border-light); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .diagram-section h4 {
  color: var(--color-primary) !important; /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Pedigree nodes */
#results.presentation-mode .node-circle {
  background: white; /* KEEP LIGHT MODE IN PRESENTATION */
  border-color: var(--color-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

#results.presentation-mode .parent-node .node-circle {
  background: linear-gradient(135deg, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
  border-color: #002455; /* PALETTE UPDATE */
}

#results.presentation-mode .child-node .node-circle {
  background: linear-gradient(135deg, #FF3838 0%, #DC0000 100%); /* PALETTE UPDATE */
  border-color: #FF3838; /* PALETTE UPDATE */
}

#results.presentation-mode .node-label {
  color: var(--color-text-tertiary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .node-genotype {
  color: var(--color-text-primary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .node-phenotype {
  color: var(--color-text-secondary); /* KEEP LIGHT MODE IN PRESENTATION */
}

#results.presentation-mode .probability-label {
  background: var(--color-primary-light); /* KEEP LIGHT MODE IN PRESENTATION */
  color: #050E3C; /* KEEP LIGHT MODE IN PRESENTATION */
}

/* Connector lines */
#results.presentation-mode .connector-horizontal,
#results.presentation-mode .connector-vertical,
#results.presentation-mode .connector-branch {
  background: linear-gradient(to right, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
}

#results.presentation-mode .connector-branch::before,
#results.presentation-mode .connector-branch::after {
  background: linear-gradient(to bottom, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
}

#results.presentation-mode .children-row .child-node:nth-child(2)::before,
#results.presentation-mode .children-row .child-node:nth-child(3)::before {
  background: linear-gradient(to bottom, #050E3C 0%, #002455 100%); /* PALETTE UPDATE */
}

/* ==========================================================================
   Footer
   ========================================================================== */

footer {
  text-align: center;
  margin-top: var(--space-3xl);
  padding: var(--space-2xl);
  color: var(--color-text-tertiary);
  font-size: 0.875rem;
}

footer p {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

/* ==========================================================================
   Responsive Design - Mobile First Approach
   ========================================================================== */

@media only screen and (max-width: 1024px) {
  #punnett-squares {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  #inheritance-diagrams > div:not(.diagram-section) {
    grid-template-columns: 1fr;
  }

  .diagram-section {
    margin-bottom: var(--space-lg);
  }
}

@media only screen and (max-width: 768px) {
  :root {
    --space-3xl: 3rem;
  }

  body {
    padding: var(--space-md);
  }

  header {
    margin-bottom: var(--space-xl);
    padding: var(--space-lg) var(--space-sm);
  }

  header h1 {
    font-size: 2rem;
  }

  header p {
    font-size: 1rem;
  }

  .parent-selection-container {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .parent-selection {
    padding: var(--space-lg);
  }

  .results-header {
    flex-direction: column;
    text-align: center;
    gap: var(--space-sm);
  }

  #results h2 {
    font-size: 1.25rem;
    justify-content: center;
  }

  .summary-badges {
    grid-template-columns: 1fr;
  }

  .summary-badge {
    width: 100%;
  }

  .punnett-section {
    padding: var(--space-md);
  }

  .punnett-table th,
  .punnett-table td {
    padding: var(--space-xs);
    font-size: 0.6875rem;
  }

  .punnett-table .phenotype {
    font-size: 0.625rem;
  }

  .presentation-toggle {
    width: 100%;
    justify-content: center;
  }

  .pedigree {
    min-width: 250px;
  }

  .parents-row {
    gap: 40px;
  }

  .children-row {
    flex-wrap: wrap;
    gap: var(--space-md);
  }

  .node-circle {
    width: 60px;
    height: 60px;
  }

  .node-genotype {
    font-size: 0.75rem;
  }

  .connector-branch {
    width: 140px;
  }
}

@media only screen and (max-width: 480px) {
  header h1 {
    font-size: 1.5rem;
  }

  .parent-selection h2 {
    font-size: 1.125rem;
  }

  button#calculate-btn {
    font-size: 0.9375rem;
    padding: var(--space-sm) var(--space-lg);
  }

  #results {
    padding: var(--space-md);
  }

  .node-circle {
    width: 55px;
    height: 55px;
  }

  .node-genotype {
    font-size: 0.6875rem;
  }

  .connector-branch {
    width: 120px;
  }

  .punnett-table .genotype {
    font-size: 0.8125rem;
  }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
  *,
  *::before,
  *::after {
    background: white !important;
    color: black !important;
    box-shadow: none !important;
    text-shadow: none !important;
  }

  body {
    padding: 0;
  }

  header,
  .presentation-toggle,
  .skip-link {
    display: none !important;
  }

  .parent-selection,
  #results,
  .punnett-section,
  .diagram-section {
    page-break-inside: avoid;
    box-shadow: none !important;
    border: 1px solid #000;
  }

  a,
  a:visited {
    text-decoration: underline;
  }

  a[href^="#"]::after,
  a[href^="javascript:"]::after {
    content: "";
  }

  h2,
  h3 {
    page-break-after: avoid;
  }
}