/* ===== CSS VARIABLES ===== */
:root {
  /* Colors - Light Theme */
  --color-primary: #4a90e2;
  --color-primary-hover: #357abd;
  --color-primary-light: #e3f2fd;
  --color-secondary: #7b68ee;
  --color-secondary-hover: #6452d4;
  --color-secondary-light: #f3f0ff;
  
  --color-success: #4caf50;
  --color-warning: #ff9800;
  --color-error: #f44336;
  --color-info: #2196f3;
  
  --color-background: #ffffff;
  --color-surface: #f5f5f5;
  --color-surface-alt: #eeeeee;
  --color-border: #e0e0e0;
  --color-border-light: #f0f0f0;
  
  --color-text-primary: #212121;
  --color-text-secondary: #757575;
  --color-text-disabled: #bdbdbd;
  --color-text-inverse: #ffffff;
  
  --color-shadow-light: rgba(0, 0, 0, 0.1);
  --color-shadow-medium: rgba(0, 0, 0, 0.15);
  --color-shadow-dark: rgba(0, 0, 0, 0.2);
  
  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --font-family-mono: 'SF Mono', Monaco, Inconsolata, 'Roboto Mono', 'Source Code Pro', monospace;
  
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.875rem;  /* 30px */
  --font-size-4xl: 2.25rem;   /* 36px */
  --font-size-5xl: 3rem;      /* 48px */
  
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Spacing */
  --spacing-xs: 0.25rem;   /* 4px */
  --spacing-sm: 0.5rem;    /* 8px */
  --spacing-md: 1rem;      /* 16px */
  --spacing-lg: 1.5rem;    /* 24px */
  --spacing-xl: 2rem;      /* 32px */
  --spacing-2xl: 3rem;     /* 48px */
  --spacing-3xl: 4rem;     /* 64px */
  
  /* Border Radius */
  --radius-sm: 0.25rem;    /* 4px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-2xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 var(--color-shadow-light);
  --shadow-md: 0 4px 6px -1px var(--color-shadow-light), 0 2px 4px -1px var(--color-shadow-light);
  --shadow-lg: 0 10px 15px -3px var(--color-shadow-light), 0 4px 6px -2px var(--color-shadow-light);
  --shadow-xl: 0 20px 25px -5px var(--color-shadow-light), 0 10px 10px -5px var(--color-shadow-light);
  --shadow-2xl: 0 25px 50px -12px var(--color-shadow-medium);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  --z-toast: 1080;
  
  /* Grid */
  --grid-columns: 12;
  --grid-gutter: var(--spacing-lg);
  
  /* Breakpoints */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
}

/* Dark Theme */
[data-theme="dark"] {
  --color-primary: #64b5f6;
  --color-primary-hover: #42a5f5;
  --color-primary-light: #1e3a8a;
  --color-secondary: #9575cd;
  --color-secondary-hover: #7e57c2;
  --color-secondary-light: #311b92;
  
  --color-success: #66bb6a;
  --color-warning: #ffb74d;
  --color-error: #ef5350;
  --color-info: #42a5f5;
  
  --color-background: #121212;
  --color-surface: #1e1e1e;
  --color-surface-alt: #2d2d2d;
  --color-border: #333333;
  --color-border-light: #404040;
  
  --color-text-primary: #f5f5f5;
  --color-text-secondary: #b0b0b0;
  --color-text-disabled: #666666;
  --color-text-inverse: #121212;
  
  --color-shadow-light: rgba(0, 0, 0, 0.3);
  --color-shadow-medium: rgba(0, 0, 0, 0.4);
  --color-shadow-dark: rgba(0, 0, 0, 0.5);
}

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

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

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
}

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

a:hover {
  color: var(--color-primary-hover);
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  font-size: inherit;
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Focus styles */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  z-index: var(--z-tooltip);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 6px;
}

/* ===== LAYOUT ===== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--spacing-lg);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

/* Grid system */
.grid {
  display: grid;
  gap: var(--grid-gutter);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
.grid-cols-6 { grid-template-columns: repeat(6, 1fr); }
.grid-cols-12 { grid-template-columns: repeat(12, 1fr); }

@media (min-width: 640px) {
  .sm\:grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
  .sm\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
  .sm\:grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
  .sm\:grid-cols-6 { grid-template-columns: repeat(6, 1fr); }
  .sm\:grid-cols-12 { grid-template-columns: repeat(12, 1fr); }
}

@media (min-width: 768px) {
  .md\:grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
  .md\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
  .md\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
  .md\:grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
  .md\:grid-cols-6 { grid-template-columns: repeat(6, 1fr); }
  .md\:grid-cols-12 { grid-template-columns: repeat(12, 1fr); }
}

@media (min-width: 1024px) {
  .lg\:grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
  .lg\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
  .lg\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
  .lg\:grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
  .lg\:grid-cols-6 { grid-template-columns: repeat(6, 1fr); }
  .lg\:grid-cols-12 { grid-template-columns: repeat(12, 1fr); }
}

/* Flexbox utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.justify-end { justify-content: flex-end; }

/* ===== COMPONENTS ===== */

/* Header */
.header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  backdrop-filter: blur(10px);
  background-color: rgba(var(--color-surface), 0.8);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo-icon {
  font-size: var(--font-size-2xl);
}

.logo-text {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.nav-list {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav-link {
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--color-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: width var(--transition-fast);
}

.nav-link:hover::after,
.nav-link:focus::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  font-size: var(--font-size-sm);
  line-height: 1;
  text-decoration: none;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Button variants */
.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
}

.btn-secondary {
  background-color: var(--color-secondary);
  color: var(--color-text-inverse);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-secondary-hover);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover:not(:disabled) {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
}

.btn-ghost:hover:not(:disabled) {
  background-color: var(--color-surface);
  color: var(--color-text-primary);
}

/* Button sizes */
.btn-small {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-xs);
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: var(--font-size-lg);
}

.btn-icon {
  padding: var(--spacing-sm);
  border-radius: var(--radius-full);
}

/* Hero Section */
.hero {
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-secondary-light) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%234a90e2' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.3;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-lg);
  color: var(--color-text-primary);
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  line-height: var(--line-height-relaxed);
}

.hero-actions {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-dino {
  width: 100%;
  max-width: 500px;
  height: auto;
}

@media (max-width: 768px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .hero-title {
    font-size: var(--font-size-3xl);
  }
}

/* Sections */
.section {
  padding: var(--spacing-3xl) 0;
}

.section-alt {
  background-color: var(--color-surface);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section-title {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 800px;
  margin: 0 auto;
}

/* Filters */
.filters-container {
  margin-bottom: var(--spacing-xl);
}

.search-box {
  position: relative;
  margin-bottom: var(--spacing-lg);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.search-input {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  padding-right: 3rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  font-size: var(--font-size-base);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.search-btn {
  position: absolute;
  right: var(--spacing-sm);
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--color-text-secondary);
  padding: var(--spacing-sm);
  cursor: pointer;
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.search-btn:hover,
.search-btn:focus {
  background-color: var(--color-surface);
  color: var(--color-primary);
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  min-width: 150px;
}

.filter-label {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.filter-select {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.filter-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.active-filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.filter-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
}

.filter-chip button {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast);
}

.filter-chip button:hover {
  background-color: rgba(0, 0, 0, 0.1);
}

/* Results Info */
.results-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
}

/* Dinosaur Grid */
.dinosaur-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

/* Dinosaur Card */
.dinosaur-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

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

.dinosaur-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
}

.dinosaur-name {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
}

.dinosaur-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.dinosaur-tag {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: var(--color-surface-alt);
  color: var(--color-text-secondary);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
}

.dinosaur-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
}

.dinosaur-stat {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.dinosaur-stat-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  font-weight: var(--font-weight-medium);
}

.dinosaur-stat-value {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

/* Loading and Empty States */
.loading-state,
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3xl);
  text-align: center;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-border);
  border-top: 4px solid var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--spacing-lg);
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.empty-icon {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-lg);
  opacity: 0.5;
}

/* Timeline */
.timeline-container {
  background-color: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.timeline-controls {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.timeline-viewport {
  width: 100%;
  height: 400px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
}

.timeline-legend {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.legend-color {
  width: 16px;
  height: 16px;
  border-radius: var(--radius-sm);
}

/* Tabs */
.calculation-tabs,
.documentation-tabs {
  margin-top: var(--spacing-xl);
}

.tab-nav,
.doc-nav {
  display: flex;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-lg);
  overflow-x: auto;
}

.tab-btn,
.doc-tab-btn {
  padding: var(--spacing-md) var(--spacing-lg);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--color-text-secondary);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.tab-btn.active,
.doc-tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-btn:hover:not(.active),
.doc-tab-btn:hover:not(.active) {
  color: var(--color-text-primary);
  background-color: var(--color-surface);
}

.tab-content,
.doc-content {
  min-height: 400px;
}

.tab-pane,
.doc-pane {
  display: none;
}

.tab-pane.active,
.doc-pane.active {
  display: block;
}

/* Calculation Content */
.calculation-content h3 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.calculation-description {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: var(--line-height-relaxed);
}

.formula-box,
.constants-box {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.formula-box h4,
.constants-box h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.formula {
  font-family: var(--font-family-mono);
  background-color: var(--color-surface-alt);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-base);
  overflow-x: auto;
}

.constant-item {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.constant-name {
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  min-width: 120px;
}

.constant-value {
  font-family: var(--font-family-mono);
  color: var(--color-text-primary);
}

.constant-reference {
  color: var(--color-primary);
  font-size: var(--font-size-sm);
}

.calculation-demo {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.calculation-demo h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.demo-inputs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  align-items: end;
  margin-bottom: var(--spacing-lg);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.input-group label {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.input-group input,
.input-group select {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  min-width: 150px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.demo-result {
  background-color: var(--color-surface-alt);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  white-space: pre-wrap;
}

.calculation-steps {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
}

.calculation-steps h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.calculation-step {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
  position: relative;
}

.calculation-step::before {
  content: counter(step);
  counter-increment: step;
  position: absolute;
  left: 0;
  top: 0;
  width: 24px;
  height: 24px;
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
}

.calculation-steps {
  counter-reset: step;
}

/* Charts */
.bmr-comparison-chart,
.speed-visualization {
  margin-top: var(--spacing-lg);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  overflow: hidden;
}

/* Verification */
.verification-controls {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.test-results {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  white-space: pre-wrap;
  max-height: 400px;
  overflow-y: auto;
}

.verification-info {
  margin-top: var(--spacing-lg);
}

.verification-info h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.verification-info p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

.verification-info ul {
  list-style: none;
  padding-left: 0;
}

.verification-info li {
  padding: var(--spacing-xs) 0;
  padding-left: var(--spacing-lg);
  position: relative;
}

.verification-info li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: var(--font-weight-bold);
}

/* Documentation */
.doc-content-inner {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-primary);
  max-height: 600px;
  overflow-y: auto;
}

.doc-content-inner h1,
.doc-content-inner h2,
.doc-content-inner h3,
.doc-content-inner h4,
.doc-content-inner h5,
.doc-content-inner h6 {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.doc-content-inner h1 {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
}

.doc-content-inner h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
}

.doc-content-inner h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
}

.doc-content-inner h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
}

.doc-content-inner p {
  margin-bottom: var(--spacing-md);
}

.doc-content-inner ul,
.doc-content-inner ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
}

.doc-content-inner li {
  margin-bottom: var(--spacing-xs);
}

.doc-content-inner code {
  background-color: var(--color-surface-alt);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
}

.doc-content-inner pre {
  background-color: var(--color-surface-alt);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
}

.doc-content-inner pre code {
  background: none;
  padding: 0;
}

.doc-content-inner blockquote {
  border-left: 4px solid var(--color-primary);
  padding-left: var(--spacing-md);
  margin: var(--spacing-lg) 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

.doc-content-inner table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--spacing-md);
}

.doc-content-inner th,
.doc-content-inner td {
  padding: var(--spacing-sm);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.doc-content-inner th {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

.doc-content-inner a {
  color: var(--color-primary);
  text-decoration: underline;
}

.doc-content-inner a:hover {
  color: var(--color-primary-hover);
}

/* Test Runner */
.test-runner {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.test-controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.test-output {
  background-color: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  white-space: pre-wrap;
  max-height: 500px;
  overflow-y: auto;
}

/* Comparison */
.comparison-container {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.comparison-selector h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-lg);
  color: var(--color-text-primary);
}

.species-selector {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  max-height: 300px;
  overflow-y: auto;
  padding: var(--spacing-md);
  background-color: var(--color-surface-alt);
  border-radius: var(--radius-lg);
}

.species-checkbox {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.species-checkbox:hover {
  background-color: var(--color-surface);
}

.species-checkbox input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--color-primary);
}

.species-checkbox label {
  cursor: pointer;
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
}

.comparison-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.comparison-results {
  margin-top: var(--spacing-lg);
}

/* FAQ */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  margin-bottom: var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  padding: var(--spacing-lg);
  background-color: var(--color-surface);
  border: none;
  text-align: left;
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color var(--transition-fast);
}

.faq-question:hover {
  background-color: var(--color-surface-alt);
}

.faq-icon {
  font-size: var(--font-size-lg);
  transition: transform var(--transition-fast);
}

.faq-question[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 var(--spacing-lg);
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal), padding var(--transition-normal);
}

.faq-question[aria-expanded="true"] + .faq-answer {
  padding: var(--spacing-lg);
  max-height: 500px;
}

.faq-answer p {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* Footer */
.footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
}

.footer-section h3 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.footer-section p {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-md);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary);
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.modal.active {
  opacity: 1;
  visibility: visible;
}

.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.modal-content {
  position: relative;
  background-color: var(--color-background);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2xl);
  max-width: 800px;
  max-height: 90vh;
  width: 90%;
  overflow: hidden;
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

.modal.active .modal-content {
  transform: scale(1);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.modal-header h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.btn-close {
  background: none;
  border: none;
  font-size: var(--font-size-2xl);
  color: var(--color-text-secondary);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.btn-close:hover,
.btn-close:focus {
  background-color: var(--color-surface);
  color: var(--color-text-primary);
}

.modal-body {
  padding: var(--spacing-lg);
  overflow-y: auto;
  max-height: calc(90vh - 80px);
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.toast {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-lg);
  min-width: 300px;
  transform: translateX(100%);
  transition: transform var(--transition-normal);
}

.toast.show {
  transform: translateX(0);
}

.toast-success {
  border-left: 4px solid var(--color-success);
}

.toast-error {
  border-left: 4px solid var(--color-error);
}

.toast-warning {
  border-left: 4px solid var(--color-warning);
}

.toast-info {
  border-left: 4px solid var(--color-info);
}

.toast-title {
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-primary);
}

.toast-message {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .nav-list {
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
  }
  
  .filters {
    flex-direction: column;
  }
  
  .filter-group {
    width: 100%;
  }
  
  .dinosaur-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-title {
    font-size: var(--font-size-3xl);
  }
  
  .section-title {
    font-size: var(--font-size-2xl);
  }
  
  .tab-nav,
  .doc-nav {
    flex-wrap: nowrap;
    overflow-x: auto;
  }
  
  .demo-inputs {
    flex-direction: column;
    align-items: stretch;
  }
  
  .comparison-actions {
    flex-direction: column;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .hero-actions {
    flex-direction: column;
  }
  
  .btn-large {
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
  }
  
  .modal-content {
    width: 95%;
  }
  
  .toast-container {
    left: var(--spacing-sm);
    right: var(--spacing-sm);
  }
  
  .toast {
    min-width: auto;
  }
}

/* Print Styles */
@media print {
  .header,
  .footer,
  .btn,
  .modal,
  .toast-container {
    display: none !important;
  }
  
  .section {
    break-inside: avoid;
    page-break-inside: avoid;
  }
  
  .dinosaur-card {
    break-inside: avoid;
    page-break-inside: avoid;
  }
}