/* =============================================
   AI TRAVEL PLANNER - SHARED DESIGN SYSTEM
   Desktop-First Modern Travel Application
   ============================================= */

/* =============================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================= */
:root {
  /* Primary Colors - Deep Teal */
  --primary-50: #f0fdfa;
  --primary-100: #ccfbf1;
  --primary-200: #99f6e4;
  --primary-300: #5eead4;
  --primary-400: #2dd4bf;
  --primary-500: #14b8a6;
  --primary-600: #0d9488;
  --primary-700: #0f766e;
  --primary-800: #115e59;
  --primary-900: #134e4a;

  /* Secondary Colors - Warm Coral */
  --secondary-50: #fff7ed;
  --secondary-100: #ffedd5;
  --secondary-200: #fed7aa;
  --secondary-300: #fdba74;
  --secondary-400: #fb923c;
  --secondary-500: #f97316;
  --secondary-600: #ea580c;

  /* Neutral Colors */
  --neutral-50: #fafafa;
  --neutral-100: #f5f5f5;
  --neutral-200: #e5e5e5;
  --neutral-300: #d4d4d4;
  --neutral-400: #a3a3a3;
  --neutral-500: #737373;
  --neutral-600: #525252;
  --neutral-700: #404040;
  --neutral-800: #262626;
  --neutral-900: #171717;

  /* Semantic Colors */
  --success: #22c55e;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --error: #ef4444;
  --error-light: #fee2e2;
  --info: #3b82f6;
  --info-light: #dbeafe;

  /* Background & Surface */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-dark: #0f172a;
  --surface-elevated: #ffffff;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #0d9488 0%, #14b8a6 100%);
  --gradient-hero: linear-gradient(
    135deg,
    #0f766e 0%,
    #14b8a6 50%,
    #2dd4bf 100%
  );
  --gradient-warm: linear-gradient(135deg, #f97316 0%, #fb923c 100%);
  --gradient-dark: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  --gradient-glass: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.9) 0%,
    rgba(255, 255, 255, 0.7) 100%
  );

  /* Typography */
  --font-family:
    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --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: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3.5rem;
  --font-size-6xl: 4.5rem;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

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

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md:
    0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg:
    0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl:
    0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 30px rgba(20, 184, 166, 0.3);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms ease;
  --transition-slower: 600ms ease;

  /* Layout */
  --header-height: 80px;
  --sidebar-width: 280px;
  --max-width: 1400px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--neutral-800);
  background-color: var(--bg-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

button,
input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  border: none;
  outline: none;
  background: none;
}

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

ul,
ol {
  list-style: none;
}

/* =============================================
   TYPOGRAPHY
   ============================================= */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--neutral-900);
}

h1 {
  font-size: var(--font-size-5xl);
}
h2 {
  font-size: var(--font-size-4xl);
}
h3 {
  font-size: var(--font-size-3xl);
}
h4 {
  font-size: var(--font-size-2xl);
}
h5 {
  font-size: var(--font-size-xl);
}
h6 {
  font-size: var(--font-size-lg);
}

.text-xs {
  font-size: var(--font-size-xs);
}
.text-sm {
  font-size: var(--font-size-sm);
}
.text-lg {
  font-size: var(--font-size-lg);
}
.text-xl {
  font-size: var(--font-size-xl);
}
.text-muted {
  color: var(--neutral-500);
}
.text-center {
  text-align: center;
}
.text-primary {
  color: var(--primary-600);
}

/* =============================================
   LAYOUT UTILITIES
   ============================================= */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-8);
}

.section {
  padding: var(--space-24) 0;
}

.flex {
  display: flex;
}
.flex-col {
  flex-direction: column;
}
.items-center {
  align-items: center;
}
.justify-center {
  justify-content: center;
}
.justify-between {
  justify-content: space-between;
}
.gap-2 {
  gap: var(--space-2);
}
.gap-4 {
  gap: var(--space-4);
}
.gap-6 {
  gap: var(--space-6);
}
.gap-8 {
  gap: var(--space-8);
}

.mt-2 {
  margin-top: var(--space-2);
}
.mt-4 {
  margin-top: var(--space-4);
}
.mt-6 {
  margin-top: var(--space-6);
}
.mt-8 {
  margin-top: var(--space-8);
}
.mb-4 {
  margin-bottom: var(--space-4);
}
.mb-6 {
  margin-bottom: var(--space-6);
}
.mb-8 {
  margin-bottom: var(--space-8);
}

/* =============================================
   BUTTONS
   ============================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-weight: var(--font-weight-medium);
  font-size: var(--font-size-base);
  line-height: 1;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow:
    var(--shadow-lg),
    0 0 40px rgba(20, 184, 166, 0.4);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--neutral-700);
  border: 1px solid var(--neutral-200);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--neutral-200);
}

.btn-outline {
  background: transparent;
  color: var(--primary-600);
  border: 2px solid var(--primary-600);
}

.btn-outline:hover:not(:disabled) {
  background: var(--primary-50);
}

.btn-ghost {
  background: transparent;
  color: var(--neutral-600);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--neutral-100);
}

.btn-white {
  background: white;
  color: var(--primary-700);
  box-shadow: var(--shadow-md);
}

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

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-lg);
}

.btn-xl {
  padding: var(--space-5) var(--space-10);
  font-size: var(--font-size-lg);
  border-radius: var(--radius-xl);
}

.btn-full {
  width: 100%;
}

.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: var(--radius-full);
}

/* =============================================
   FORM ELEMENTS
   ============================================= */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--neutral-700);
  margin-bottom: var(--space-2);
}

.form-input {
  width: 100%;
  padding: var(--space-4);
  font-size: var(--font-size-base);
  color: var(--neutral-800);
  background: var(--bg-primary);
  border: 2px solid var(--neutral-200);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.form-input:focus {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 4px rgba(20, 184, 166, 0.1);
}

.form-input::placeholder {
  color: var(--neutral-400);
}

.form-input-lg {
  padding: var(--space-5);
  font-size: var(--font-size-lg);
}

textarea.form-input {
  min-height: 140px;
  resize: vertical;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23737373' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-4) center;
  background-size: 20px;
  padding-right: var(--space-12);
  cursor: pointer;
}

/* =============================================
   DUAL RANGE SLIDER (Budget)
   ============================================= */
.budget-slider-container {
  background: var(--bg-secondary);
  border: 2px solid var(--neutral-200);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: all var(--transition-fast);
}

.budget-slider-container:hover {
  border-color: var(--primary-300);
}

.budget-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.budget-value {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--primary-700);
  background: linear-gradient(
    135deg,
    var(--primary-100) 0%,
    var(--primary-50) 100%
  );
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-lg);
  min-width: 120px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.budget-separator {
  color: var(--neutral-400);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
}

.range-slider-wrapper {
  position: relative;
  height: 20px;
  margin: var(--space-4) 0;
}

.range-track {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  left: 0;
  right: 0;
  height: 8px;
  background: var(--neutral-200);
  border-radius: var(--radius-full);
}

.range-track::before {
  content: "";
  position: absolute;
  top: 0;
  left: var(--range-left, 0%);
  right: calc(100% - var(--range-right, 100%));
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: all 0.1s ease;
}

.range-slider {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  pointer-events: none;
  z-index: 2;
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 24px;
  height: 24px;
  background: white;
  border: 3px solid var(--primary-500);
  border-radius: 50%;
  cursor: pointer;
  pointer-events: auto;
  box-shadow:
    var(--shadow-md),
    0 0 0 4px rgba(20, 184, 166, 0.1);
  transition: all var(--transition-fast);
}

.range-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow:
    var(--shadow-lg),
    0 0 0 6px rgba(20, 184, 166, 0.2);
  border-color: var(--primary-600);
}

.range-slider::-webkit-slider-thumb:active {
  transform: scale(1.1);
  background: var(--primary-50);
}

.range-slider::-moz-range-thumb {
  width: 24px;
  height: 24px;
  background: white;
  border: 3px solid var(--primary-500);
  border-radius: 50%;
  cursor: pointer;
  pointer-events: auto;
  box-shadow:
    var(--shadow-md),
    0 0 0 4px rgba(20, 184, 166, 0.1);
  transition: all var(--transition-fast);
}

.range-slider::-moz-range-thumb:hover {
  transform: scale(1.15);
  box-shadow:
    var(--shadow-lg),
    0 0 0 6px rgba(20, 184, 166, 0.2);
  border-color: var(--primary-600);
}

.range-slider::-moz-range-track {
  background: transparent;
}

.budget-range-labels {
  display: flex;
  justify-content: space-between;
  font-size: var(--font-size-sm);
  color: var(--neutral-500);
  margin-top: var(--space-3);
}

/* =============================================
   CARDS
   ============================================= */
.card {
  background: var(--surface-elevated);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-lg);
}

.card-glass {
  background: var(--gradient-glass);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.5);
}

/* =============================================
   BADGES
   ============================================= */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-full);
  background: var(--neutral-100);
  color: var(--neutral-700);
}

.badge-primary {
  background: var(--primary-100);
  color: var(--primary-700);
}

.badge-success {
  background: var(--success-light);
  color: #166534;
}

.badge-warning {
  background: var(--warning-light);
  color: #92400e;
}

.badge-error {
  background: var(--error-light);
  color: #991b1b;
}

/* =============================================
   PROGRESS BAR
   ============================================= */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--neutral-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

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

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

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

@keyframes bounce {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-15px);
  }
}

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

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.animate-fade-in {
  animation: fadeIn var(--transition-normal) ease forwards;
}
.animate-fade-in-up {
  animation: fadeInUp var(--transition-slow) ease forwards;
}
.animate-fade-in-down {
  animation: fadeInDown var(--transition-slow) ease forwards;
}
.animate-slide-in-left {
  animation: slideInLeft var(--transition-slow) ease forwards;
}
.animate-slide-in-right {
  animation: slideInRight var(--transition-slow) ease forwards;
}
.animate-pulse {
  animation: pulse 2s infinite;
}
.animate-bounce {
  animation: bounce 2s infinite;
}
.animate-float {
  animation: float 3s ease-in-out infinite;
}
.animate-spin {
  animation: spin 1s linear infinite;
}

/* Page transition */
.page-transition {
  opacity: 0;
  animation: fadeIn 0.4s ease forwards;
}

.page-exit {
  animation: fadeIn 0.3s ease reverse forwards;
}

/* =============================================
   SCROLLBAR
   ============================================= */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--neutral-100);
}

::-webkit-scrollbar-thumb {
  background: var(--neutral-300);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--neutral-400);
}