/* =====================================================
   LITTLE HONGKONG - HERITAGE MINIMALIST DESIGN SYSTEM
   Version: 1.0 | Dark Theme | Quiet UI Philosophy
   ===================================================== */

/* --- CSS Variables (Design Tokens) --- */
:root {
  /* Surface Colors - Elegant Slate Charcoal (Xám sang trọng) */
  --surface: #1b211f;
  --surface-dim: #161b19;
  --surface-bright: #38423e;
  --surface-container-lowest: #101413;
  --surface-container-low: #1f2624;
  --surface-container: #232b28;
  --surface-container-high: #2c3633;
  --surface-container-highest: #36413d;
  --surface-variant: #36413d;

  /* On Surface - Pearl / warm neutral */
  --on-surface: #ece4d6;
  --on-surface-variant: #c7c2b4;
  --inverse-surface: #ece4d6;
  --inverse-on-surface: #2a302e;

  /* Primary - Metallic Lantern Red (Đỏ kim loại) */
  --primary: #ff9d8e;
  --on-primary: #5e0a0c;
  --primary-container: #a31f24;
  --on-primary-container: #ffd9d3;
  --inverse-primary: #b52424;
  --surface-tint: #ff9d8e;
  --primary-fixed: #ffd9d3;
  --primary-fixed-dim: #ff9d8e;
  --on-primary-fixed: #3d0306;
  --on-primary-fixed-variant: #8a1419;

  /* Secondary - Pearl / Metallic Gold (Vàng ngọc) */
  --secondary: #e7d2a0;
  --on-secondary: #3a2c08;
  --secondary-container: #c9a24b;
  --on-secondary-container: #3a2c08;
  --secondary-fixed: #f3deac;
  --secondary-fixed-dim: #d6b463;
  --on-secondary-fixed: #241a04;
  --on-secondary-fixed-variant: #5a4514;

  /* Tertiary - Neutral */
  --tertiary: #c8c6c5;
  --on-tertiary: #313030;
  --tertiary-container: #5d5c5c;
  --on-tertiary-container: #d7d5d4;
  --tertiary-fixed: #e5e2e1;
  --tertiary-fixed-dim: #c8c6c5;
  --on-tertiary-fixed: #1c1b1b;
  --on-tertiary-fixed-variant: #474746;

  /* Error */
  --error: #ffb4ab;
  --on-error: #690005;
  --error-container: #93000a;
  --on-error-container: #ffdad6;

  /* Outline */
  --outline: #8d958c;
  --outline-variant: #41504a;

  /* Background */
  --background: #1b211f;
  --on-background: #ece4d6;

  /* Typography */
  --font-serif: 'Playfair Display', 'Noto Serif', Georgia, serif;
  --font-sans: 'Geist', system-ui, sans-serif;

  /* Font Sizes */
  --text-display-lg: 48px;
  --text-headline-lg: 32px;
  --text-headline-md: 24px;
  --text-headline-sm: 20px;
  --text-body-lg: 18px;
  --text-body-md: 16px;
  --text-body-sm: 14px;
  --text-label-lg: 14px;
  --text-label-md: 12px;

  /* Spacing */
  --spacing-unit: 8px;
  --spacing-gutter: 16px;
  --spacing-section-gap: 120px;
  --spacing-container-mobile: 24px;
  --spacing-container-desktop: 80px;

  /* Border Radius */
  --radius-sm: 0.125rem;
  --radius-md: 0.25rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
  --transition-cubic: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--background);
  color: var(--on-surface);
  font-family: var(--font-sans);
  font-size: var(--text-body-md);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
.font-display-lg {
  font-family: var(--font-serif);
  font-size: var(--text-display-lg);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.font-headline-lg {
  font-family: var(--font-serif);
  font-size: var(--text-headline-lg);
  font-weight: 500;
  line-height: 1.3;
}

.font-headline-md {
  font-family: var(--font-serif);
  font-size: var(--text-headline-md);
  font-weight: 500;
  line-height: 1.4;
}

.font-headline-sm {
  font-family: var(--font-serif);
  font-size: var(--text-headline-sm);
  font-weight: 500;
  line-height: 1.4;
}

.font-body-lg {
  font-family: var(--font-sans);
  font-size: var(--text-body-lg);
  font-weight: 400;
  line-height: 1.6;
}

.font-body-md {
  font-family: var(--font-sans);
  font-size: var(--text-body-md);
  font-weight: 400;
  line-height: 1.6;
}

.font-body-sm {
  font-family: var(--font-sans);
  font-size: var(--text-body-sm);
  font-weight: 400;
  line-height: 1.5;
}

.font-label-lg {
  font-family: var(--font-sans);
  font-size: var(--text-label-lg);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.font-label-md {
  font-family: var(--font-sans);
  font-size: var(--text-label-md);
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.05em;
}

/* --- Material Symbols --- */
.material-symbols-outlined {
  font-family: 'Material Symbols Outlined';
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  vertical-align: middle;
  user-select: none;
}

/* --- Custom Scrollbar --- */
::-webkit-scrollbar {
  width: 4px;
  height: 4px;
}
::-webkit-scrollbar-track {
  background: var(--surface);
}
::-webkit-scrollbar-thumb {
  background: var(--surface-variant);
  border-radius: 2px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--outline-variant);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--surface-variant) var(--surface);
}

/* --- Selection --- */
::selection {
  background-color: var(--primary-container);
  color: var(--on-primary-container);
}

/* --- Surface Classes --- */
.bg-surface { background-color: var(--surface); }
.bg-surface-container-lowest { background-color: var(--surface-container-lowest); }
.bg-surface-container-low { background-color: var(--surface-container-low); }
.bg-surface-container { background-color: var(--surface-container); }
.bg-surface-container-high { background-color: var(--surface-container-high); }
.bg-surface-container-highest { background-color: var(--surface-container-highest); }
.bg-primary-container { background-color: var(--primary-container); }
.bg-secondary-container { background-color: var(--secondary-container); }
.bg-secondary { background-color: var(--secondary); }
.bg-primary { background-color: var(--primary); }
.bg-background { background-color: var(--background); }

/* --- Text Colors --- */
.text-on-surface { color: var(--on-surface); }
.text-on-surface-variant { color: var(--on-surface-variant); }
.text-primary { color: var(--primary); }
.text-secondary { color: var(--secondary); }
.text-on-primary-container { color: var(--on-primary-container); }
.text-on-secondary-container { color: var(--on-secondary-container); }
.text-on-primary { color: var(--on-primary); }
.text-outline { color: var(--outline); }

/* --- Border Colors --- */
.border-outline-variant\/10 { border-color: rgba(90, 64, 62, 0.1); }
.border-outline-variant\/20 { border-color: rgba(90, 64, 62, 0.2); }
.border-outline-variant\/30 { border-color: rgba(90, 64, 62, 0.3); }
.border-outline\/20 { border-color: rgba(170, 137, 134, 0.2); }
.border-primary\/20 { border-color: rgba(255, 180, 172, 0.2); }
.border-primary\/30 { border-color: rgba(255, 180, 172, 0.3); }
.border-secondary\/20 { border-color: rgba(255, 226, 171, 0.2); }
.border-secondary\/30 { border-color: rgba(255, 226, 171, 0.3); }
.border-secondary\/40 { border-color: rgba(255, 226, 171, 0.4); }
.border-secondary\/50 { border-color: rgba(255, 226, 171, 0.5); }
.border-outline { border-color: var(--outline); }
.border-outline-variant { border-color: var(--outline-variant); }
.border-primary-container { border-color: var(--primary-container); }
.border-secondary-container { border-color: var(--secondary-container); }

/* --- Heritage Card --- */
.heritage-card {
  background: linear-gradient(145deg, var(--surface-container-low), var(--surface));
  border: 0.5px solid rgba(235, 225, 208, 0.1);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}
.heritage-card:hover {
  border-color: rgba(255, 191, 0, 0.2);
  box-shadow: 0 10px 30px -15px rgba(0, 0, 0, 0.5);
}

/* --- Glass Panel --- */
.glass-panel {
  background: rgba(35, 31, 21, 0.6);
  backdrop-filter: blur(12px);
  border: 0.5px solid rgba(255, 191, 0, 0.1);
}

/* --- Lantern Glow Effect --- */
.lantern-glow {
  box-shadow: 0 0 20px rgba(255, 191, 0, 0.08);
}
.lantern-glow:hover {
  box-shadow: 0 0 15px 2px rgba(255, 191, 0, 0.15);
}

/* --- Quiet Shadow --- */
.quiet-shadow {
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

/* --- Faded Red Button --- */
.faded-red-btn {
  background-color: var(--primary-container);
  color: var(--on-primary-container);
  transition: background-color var(--transition-fast);
}
.faded-red-btn:hover {
  background-color: #92030f;
}

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

@keyframes pulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.6; }
}

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

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

.animate-pulse {
  animation: pulse 2s ease-in-out infinite;
}

.animate-ping {
  animation: ping 1s cubic-bezier(0, 0, 0.2, 1) infinite;
}

@keyframes ping {
  75%, 100% {
    transform: scale(2);
    opacity: 0;
  }
}

.fade-in-up {
  animation: fadeInUp 0.8s ease-out forwards;
}

.float-anim {
  animation: subtle-float 6s ease-in-out infinite;
}

.chart-pulse {
  animation: chart-pulse 4s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* --- Scroll Animations --- */
.section-fade-in {
  animation: fadeIn 1.2s ease-out forwards;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Utility Classes --- */
.tracking-widest { letter-spacing: 0.2em; }
.tracking-tight { letter-spacing: -0.02em; }
.tracking-tighter { letter-spacing: -0.03em; }
.uppercase { text-transform: uppercase; }
.italic { font-style: italic; }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }
.opacity-10 { opacity: 0.1; }
.opacity-20 { opacity: 0.2; }
.opacity-30 { opacity: 0.3; }
.opacity-40 { opacity: 0.4; }
.opacity-50 { opacity: 0.5; }
.opacity-60 { opacity: 0.6; }
.opacity-70 { opacity: 0.7; }
.opacity-80 { opacity: 0.8; }
.pointer-events-none { pointer-events: none; }
.whitespace-nowrap { white-space: nowrap; }
.overflow-hidden { overflow: hidden; }

/* --- Hide Scrollbar --- */
.hide-scrollbar::-webkit-scrollbar { display: none; }
.hide-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }

/* --- Line Clamp --- */
.line-clamp-1 {
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* --- Press Effect --- */
.press-down:active {
  transform: scale(0.95);
  transition: transform 0.1s ease;
}

/* --- Gradient Overlays --- */
.overlay-vignette {
  background: linear-gradient(
    to bottom,
    transparent 0%,
    rgba(23, 19, 9, 0.7) 50%,
    rgba(23, 19, 9, 1) 100%
  );
}

/* --- Background Patterns --- */
.grid-subtle {
  background-image:
    linear-gradient(to right, rgba(170, 137, 134, 0.05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(170, 137, 134, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
}

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

/* --- Responsive Typography Scale --- */
@media (max-width: 768px) {
  .font-display-lg {
    font-size: 36px;
  }
  .font-headline-lg {
    font-size: 28px;
  }
  .font-headline-md {
    font-size: 22px;
  }
}

/* --- Responsive Spacing --- */
@media (max-width: 768px) {
  :root {
    --spacing-container-mobile: 16px;
    --spacing-section-gap: 80px;
  }
}