/* ==========================================================================
   AeroSky Flight Booking System - Master Design System & Luxury Aviation Theme
   Theme: Royal Sapphire & Champagne Gold (with Live Dark / Light Modes)
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@500;600;700;800&display=swap');

:root {
  /* Brand Colors - Royal Sapphire & Champagne Gold */
  --primary: #1d4ed8;            /* Royal Sapphire */
  --primary-hover: #1e40af;
  --primary-dark: #172554;
  --primary-light: #dbeafe;
  --primary-subtle: #eff6ff;
  
  --secondary: #0b1329;          /* Deep Midnight Navy */
  --secondary-light: #1e293b;
  --secondary-muted: #334155;

  --accent: #d97706;             /* Warm Champagne Gold */
  --accent-hover: #b45309;
  --accent-light: #fef3c7;
  --accent-gold: #f59e0b;

  --action: #e11d48;             /* Coral / Crimson Jet */
  --action-hover: #be123c;
  --action-light: #ffe4e6;

  --success: #10b981;
  --success-light: #d1fae5;
  --warning: #f97316;
  --warning-light: #ffedd5;
  --danger: #ef4444;
  --danger-light: #fee2e2;

  /* Surfaces & Neutrals (Light Mode Default) */
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --border-color: #e2e8f0;
  --border-subtle: #f1f5f9;
  
  --text-main: #0b1329;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --text-white: #ffffff;

  /* Typography */
  --font-main: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Space Grotesk', sans-serif;

  /* Elevations */
  --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.08), 0 1px 2px -1px rgb(0 0 0 / 0.08);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.08), 0 2px 4px -2px rgb(0 0 0 / 0.08);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.08);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-gold: 0 4px 20px rgba(217, 119, 6, 0.25);

  /* Border Radii */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);

  --max-width: 1240px;
  --nav-height: 76px;
}

/* Dark Mode Theme Definition */
[data-theme="dark"] {
  --bg-body: #060913;
  --bg-surface: #0b1329;
  --bg-card: #0f1a36;
  --bg-card-subtle: #152244;
  --border-color: #1e2c4f;
  --border-subtle: #152244;

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-light: #64748b;

  --primary-subtle: #172554;
  --accent-light: #451a03;
  --success-light: #064e3b;
}

/* Base Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

main { flex: 1; }

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

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

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

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

ul, ol { list-style: none; }

/* Container & Grid Utilities */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.text-center { text-align: center; }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--text-main);
  line-height: 1.25;
  font-weight: 700;
}

h1 { font-size: clamp(2.1rem, 4.5vw, 3.4rem); }
h2 { font-size: clamp(1.65rem, 3vw, 2.3rem); }
h3 { font-size: 1.45rem; }
h4 { font-size: 1.2rem; }
h5 { font-size: 1rem; }

/* Buttons with Champagne & Sapphire Aesthetics */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  white-space: nowrap;
  line-height: 1.2;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.btn-primary {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  color: #fff;
  box-shadow: 0 4px 14px rgba(29, 78, 216, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #1e40af 0%, #172554 100%);
  box-shadow: 0 6px 18px rgba(29, 78, 216, 0.45);
  transform: translateY(-1px);
}

.btn-accent {
  background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
  color: #fff;
  box-shadow: 0 4px 14px rgba(217, 119, 6, 0.35);
}

.btn-accent:hover {
  background: linear-gradient(135deg, #b45309 0%, #78350f 100%);
  transform: translateY(-1px);
}

.btn-action {
  background: linear-gradient(135deg, var(--action) 0%, var(--action-hover) 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(225, 29, 72, 0.35);
}

.btn-action:hover {
  background: linear-gradient(135deg, var(--action-hover) 0%, #9f1239 100%);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--secondary);
  color: #fff;
}

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

.btn-outline:hover {
  background: var(--bg-card-subtle);
  border-color: var(--text-muted);
}

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

.btn-outline-primary:hover {
  background: var(--primary-subtle);
}

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

.btn-outline-accent:hover {
  background: var(--accent-light);
}

.btn-sm {
  padding: 0.5rem 0.95rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.95rem 1.85rem;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-block { width: 100%; }

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.badge-primary { background: var(--primary-light); color: var(--primary-dark); }
.badge-accent { background: var(--accent-light); color: var(--accent-hover); }
.badge-action { background: var(--action-light); color: var(--action); }
.badge-success { background: var(--success-light); color: #065f46; }
.badge-warning { background: var(--warning-light); color: #9a3412; }
.badge-muted { background: var(--border-color); color: var(--text-muted); }

/* Header & Navigation */
.top-bar {
  background-color: #060913;
  color: #94a3b8;
  font-size: 0.825rem;
  padding: 0.45rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.top-bar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.top-bar-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.top-bar-item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.site-header {
  background: var(--bg-surface);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #1d4ed8 0%, #d97706 100%);
  color: #fff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(29, 78, 216, 0.4);
}

.logo-icon svg {
  width: 24px;
  height: 24px;
}

.brand-logo span {
  color: var(--accent);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  position: relative;
  padding: 0.4rem 0;
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2.5px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

/* Theme Switcher Toggle */
.theme-toggle-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card-subtle);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--primary);
  background: var(--primary-subtle);
}

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  padding: 6px;
}

.mobile-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--text-main);
  border-radius: 2px;
}

/* Footer */
.site-footer {
  background-color: #060913;
  color: #94a3b8;
  padding-top: 4.5rem;
  margin-top: auto;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1.5fr;
  gap: 2.5rem;
  padding-bottom: 3.5rem;
}

.footer-brand p {
  margin-top: 1rem;
  font-size: 0.925rem;
  line-height: 1.6;
  max-width: 320px;
}

.footer-brand .brand-logo { color: #fff; }

.footer-socials {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.social-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  transition: var(--transition-fast);
}

.social-btn:hover {
  background: var(--primary);
  transform: translateY(-2px);
}

.footer-col h4 {
  color: #ffffff;
  font-size: 1.05rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-main);
  font-weight: 600;
}

.footer-links li { margin-bottom: 0.7rem; }

.footer-links a {
  color: #94a3b8;
  font-size: 0.9rem;
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: #ffffff;
  padding-left: 4px;
}

.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1rem;
}

.newsletter-input-group {
  display: flex;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-md);
  overflow: hidden;
  padding: 3px;
}

.newsletter-input-group input {
  background: transparent;
  border: none;
  padding: 0.65rem 0.85rem;
  color: #fff;
  font-size: 0.88rem;
  width: 100%;
  outline: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 1.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.payment-badges {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.payment-badge {
  background: #ffffff;
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-xs);
  font-size: 0.75rem;
  font-weight: 700;
  color: #0f172a;
}

/* Reusable Cards & Forms */
.section { padding: 5rem 0; }

.section-header {
  text-align: center;
  max-width: 650px;
  margin: 0 auto 3.5rem auto;
}

.section-subtitle {
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.45rem;
  display: block;
}

.section-title { margin-bottom: 0.75rem; }

.section-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
}

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

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(217, 119, 6, 0.35);
}

.form-group { margin-bottom: 1.25rem; }

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.4rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: var(--bg-surface);
  color: var(--text-main);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  outline: none;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.2);
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%23d97706'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 16px;
  padding-right: 2.5rem;
}

.custom-checkbox {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  cursor: pointer;
  font-size: 0.9rem;
  user-select: none;
}

.custom-checkbox input[type="checkbox"],
.custom-checkbox input[type="radio"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Toast Container */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.toast {
  background: var(--secondary);
  color: #ffffff;
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  border-left: 4px solid var(--accent);
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

/* Responsive */
@media (max-width: 1024px) {
  .footer-top { grid-template-columns: 1fr 1fr 1fr; }
  .footer-brand { grid-column: span 3; }
}

@media (max-width: 768px) {
  :root { --nav-height: 66px; }
  .top-bar { display: none; }
  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: var(--bg-surface);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    box-shadow: var(--shadow-lg);
    border-bottom: 1px solid var(--border-color);
    transform: translateY(-150%);
    transition: transform var(--transition-normal);
    z-index: 999;
  }
  .nav-menu.open { transform: translateY(0); }
  .mobile-toggle { display: flex; }
  .footer-top { grid-template-columns: 1fr; gap: 2rem; }
  .footer-brand { grid-column: span 1; }
  .footer-bottom { flex-direction: column; gap: 1rem; text-align: center; }
}