/* ===== CSS CUSTOM PROPERTIES ===== */
:root {
  /* Colors */
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #6366f1;
  --accent-color: #f59e0b;
  
  --success-color: #22c55e;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-light: #9ca3af;
  --text-white: #ffffff;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f3f4f6;
  --bg-overlay: rgba(0, 0, 0, 0.5);
  
  --border-color: #e5e7eb;
  --border-color-hover: #d1d5db;
  
  --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);
  
  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
  
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  --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-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  --spacing-20: 5rem;
  
  /* Layout */
  --max-width-sm: 24rem;
  --max-width-md: 28rem;
  --max-width-lg: 32rem;
  --max-width-xl: 36rem;
  --max-width-2xl: 42rem;
  --max-width-4xl: 56rem;
  --max-width-full: 100%;
  
  /* Border radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-full: 9999px;
  
  /* 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: 1040;
  --z-popover: 1050;
  --z-tooltip: 1070;
}

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

html {
  font-size: 16px;
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

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

/* ===== ACCESSIBILITY ===== */
.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;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  z-index: var(--z-tooltip);
  padding: var(--spacing-2) var(--spacing-4);
  background: var(--primary-color);
  color: var(--text-white);
  text-decoration: none;
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  transition: var(--transition-fast);
}

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

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

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
  margin-bottom: var(--spacing-4);
  color: var(--text-secondary);
}

/* ===== LAYOUT ===== */
.app-container {
  position: relative;
  max-width: var(--max-width-sm);
  margin: 0 auto;
  background: var(--bg-primary);
  min-height: 100vh;
  box-shadow: var(--shadow-xl);
}

.screen {
  display: none;
  width: 100%;
  min-height: 100vh;
  position: relative;
  animation: fadeIn 0.3s ease-in-out;
}

.screen.active {
  display: block;
}

.screen-header {
  background: var(--primary-color);
  color: var(--text-white);
  padding: var(--spacing-4);
  text-align: center;
}

.screen-header h1 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: 0;
}

.screen-content {
  padding: var(--spacing-5);
  padding-bottom: var(--spacing-20);
}

/* ===== NAVIGATION ===== */
.navigation {
  position: fixed;
  top: var(--spacing-5);
  right: var(--spacing-5);
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-4);
  z-index: var(--z-fixed);
  min-width: 200px;
}

.navigation__title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-3);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.navigation__list {
  list-style: none;
}

.nav-btn {
  display: block;
  width: 100%;
  margin-bottom: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-4);
  background: var(--bg-tertiary);
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
  transition: var(--transition-fast);
}

.nav-btn:hover {
  background: var(--border-color);
  transform: translateY(-1px);
}

.nav-btn:active {
  transform: translateY(0);
}

/* ===== LANDING PAGE ===== */
.landing-page {
  width: 100%;
  background: var(--bg-primary);
}

.hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: var(--text-white);
  padding: var(--spacing-20) var(--spacing-5);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, rgba(255,255,255,0.1) 25%, transparent 25%), 
              linear-gradient(-45deg, rgba(255,255,255,0.1) 25%, transparent 25%);
  background-size: 60px 60px;
  animation: float 20s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
}

.hero__title {
  font-size: var(--font-size-5xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-5);
  position: relative;
  z-index: 1;
}

.hero__subtitle {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-10);
  opacity: 0.9;
  position: relative;
  z-index: 1;
}

.hero__mockup {
  background: rgba(255,255,255,0.1);
  padding: var(--spacing-5);
  border-radius: var(--radius-2xl);
  max-width: 300px;
  margin: 0 auto;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.2);
  position: relative;
  z-index: 1;
}

/* ===== FEATURES SECTION ===== */
.features {
  padding: var(--spacing-20) var(--spacing-5);
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-8);
  max-width: var(--max-width-4xl);
  margin: 0 auto;
}

.feature-card {
  text-align: center;
  padding: var(--spacing-10) var(--spacing-5);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-md);
  background: var(--bg-primary);
  transition: var(--transition-normal);
}

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

.feature-icon {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-5);
  display: block;
}

.feature-title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-4);
}

.feature-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ===== CTA SECTION ===== */
.cta-section {
  background: var(--bg-tertiary);
  padding: var(--spacing-16) var(--spacing-5);
  text-align: center;
}

.cta-title {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-4);
}

.cta-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-8);
  max-width: var(--max-width-2xl);
  margin-left: auto;
  margin-right: auto;
}

.btn-row {
  display: flex;
  gap: var(--spacing-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-4) var(--spacing-6);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  text-align: center;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-2xl);
  cursor: pointer;
  transition: var(--transition-normal);
  white-space: nowrap;
  min-height: 48px;
  min-width: 120px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.btn-primary {
  color: var(--text-white);
  background: var(--primary-color);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover:not(:disabled) {
  color: var(--text-white);
  background: var(--primary-color);
  transform: translateY(-2px);
}

/* ===== FORM ELEMENTS ===== */
.trip-form {
  max-width: var(--max-width-md);
  margin: 0 auto;
}

.input-group {
  margin-bottom: var(--spacing-5);
}

.label {
  display: block;
  margin-bottom: var(--spacing-2);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  font-size: var(--font-size-sm);
}

.input {
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-base);
  font-family: inherit;
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: var(--transition-fast);
  min-height: 48px;
}

.input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.input:readonly {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
}

/* ===== TAGS ===== */
.tag-container {
  display: flex;
  gap: var(--spacing-2);
  flex-wrap: wrap;
}

.tag {
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary-color);
  padding: var(--spacing-2) var(--spacing-3);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  border: 1px solid rgba(37, 99, 235, 0.2);
}

/* ===== SLIDER ===== */
.slider-container {
  margin: var(--spacing-5) 0;
}

.slider {
  width: 100%;
  height: 6px;
  border-radius: var(--radius-sm);
  background: var(--border-color);
  outline: none;
  appearance: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  box-shadow: var(--shadow-md);
}

.slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow-md);
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  margin-top: var(--spacing-2);
}

/* ===== MAP PLACEHOLDER ===== */
.map-placeholder {
  height: 200px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-2xl);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-5);
  border: 2px dashed var(--border-color);
  text-align: center;
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
}

/* ===== ITINERARY ===== */
.itinerary {
  margin-bottom: var(--spacing-8);
}

.day-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-4);
  margin-bottom: var(--spacing-3);
  transition: var(--transition-fast);
}

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

.day-title {
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-2);
}

.day-highlights {
  font-size: var(--font-size-sm);
  margin: 0;
}

/* ===== LOCATION BANNER ===== */
.location-banner {
  background: #fef3c7;
  border: 1px solid var(--warning-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-4);
  margin-bottom: var(--spacing-5);
  text-align: center;
}

.location-title {
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-1);
}

.time-stopped {
  color: #92400e;
  font-size: var(--font-size-sm);
  margin: 0;
}

/* ===== OPTIONS CONTAINER ===== */
.options-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
}

.option-card {
  border-radius: var(--radius-2xl);
  padding: var(--spacing-4);
  border: 2px solid;
  cursor: pointer;
  transition: var(--transition-normal);
  background: transparent;
  text-align: left;
  min-height: 48px;
}

.option-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.option-green {
  background: #f0fdf4;
  border-color: var(--success-color);
}

.option-yellow {
  background: #fffbeb;
  border-color: var(--warning-color);
}

.option-red {
  background: #fef2f2;
  border-color: var(--error-color);
}

.option-title {
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-2);
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  flex-wrap: wrap;
}

.option-description {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.timer {
  background: #fee2e2;
  color: #dc2626;
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
}

/* ===== CHOICE CARDS ===== */
.choices-container {
  margin-bottom: var(--spacing-6);
}

.choice-card {
  border: 2px solid var(--border-color);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-4);
  margin-bottom: var(--spacing-3);
  cursor: pointer;
  transition: var(--transition-normal);
  background: var(--bg-primary);
}

.choice-card:hover {
  border-color: var(--primary-color);
  background: #f8faff;
  transform: translateY(-1px);
}

.choice-card.selected {
  border-color: var(--primary-color);
  background: rgba(37, 99, 235, 0.05);
}

.choice-title {
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-2);
}

.choice-details {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  line-height: var(--line-height-relaxed);
}

.alternative-text {
  text-align: center;
  margin: var(--spacing-5) 0;
  color: var(--text-light);
  font-size: var(--font-size-sm);
}

/* ===== ACTION BUTTONS ===== */
.action-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

/* ===== BOTTOM NAVIGATION ===== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  max-width: var(--max-width-sm);
  width: 100%;
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  display: flex;
  padding: var(--spacing-3);
  z-index: var(--z-fixed);
  box-shadow: var(--shadow-lg);
}

.nav-item {
  flex: 1;
  text-align: center;
  padding: var(--spacing-2);
  color: var(--text-light);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  border: none;
  background: transparent;
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  min-height: 40px;
}

.nav-item.active,
.nav-item[aria-selected="true"] {
  color: var(--primary-color);
  background: rgba(37, 99, 235, 0.1);
}

.nav-item:hover {
  color: var(--primary-color);
}

/* ===== LOADING OVERLAY ===== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-overlay);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top: 4px solid var(--text-white);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== RESPONSIVE DESIGN ===== */

/* Mobile First - Base styles above are for mobile */

/* Small tablets and large phones (576px and up) */
@media (min-width: 36rem) {
  .app-container {
    max-width: var(--max-width-md);
  }
  
  .hero__title {
    font-size: var(--font-size-5xl);
  }
  
  .feature-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-10);
  }
  
  .btn-row {
    flex-direction: row;
  }
}

/* Tablets (768px and up) */
@media (min-width: 48rem) {
  .app-container {
    max-width: var(--max-width-lg);
  }
  
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .action-buttons {
    flex-direction: row;
    justify-content: center;
  }
  
  .navigation {
    top: var(--spacing-6);
    right: var(--spacing-6);
  }
}

/* Desktops (1024px and up) */
@media (min-width: 64rem) {
  .app-container {
    max-width: var(--max-width-xl);
  }
  
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .hero {
    padding: var(--spacing-20) var(--spacing-10);
  }
  
  .hero__title {
    font-size: clamp(var(--font-size-4xl), 5vw, var(--font-size-5xl));
  }
}

/* Large desktops (1280px and up) */
@media (min-width: 80rem) {
  .app-container {
    max-width: var(--max-width-2xl);
  }
  
  .landing-page {
    max-width: var(--max-width-4xl);
    margin: 0 auto;
  }
}

/* ===== PRINT STYLES ===== */
@media print {
  .navigation,
  .bottom-nav,
  .loading-overlay {
    display: none !important;
  }
  
  .screen {
    display: block !important;
    page-break-inside: avoid;
  }
  
  .hero {
    background: var(--bg-primary) !important;
    color: var(--text-primary) !important;
  }
}

/* ===== HIGH CONTRAST MODE ===== */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000000;
    --text-secondary: #000000;
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  }
}

/* ===== REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .hero::before {
    animation: none;
  }
  
  .loading-spinner {
    animation: none;
    border: 4px solid var(--primary-color);
  }
}

/* ===== DARK MODE SUPPORT ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    
    --border-color: #4b5563;
    --border-color-hover: #6b7280;
    
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4);
  }
  
  .option-green {
    background: #064e3b;
  }
  
  .option-yellow {
    background: #78350f;
  }
  
  .option-red {
    background: #7f1d1d;
  }
  
  .location-banner {
    background: #78350f;
    color: #fbbf24;
  }
  
  .time-stopped {
    color: #fbbf24;
  }
}