/* ===================================================================
   YouTube AI Studio — Global Design System
   Modern Dark Mode with Glassmorphic Elements
   =================================================================== */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Background palette */
  --bg-deepest: #030303;
  --bg-deep: #050508;
  --bg-base: #070711;
  --bg-surface: #09090f;
  --bg-elevated: #0d0d15;
  --bg-card: #0f0f1a;

  /* Glass surfaces */
  --glass-bg-subtle: rgba(255, 255, 255, 0.03);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-bg-strong: rgba(255, 255, 255, 0.07);
  --glass-border-subtle: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-strong: rgba(255, 255, 255, 0.12);

  /* Text */
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.9);
  --text-muted: rgba(255, 255, 255, 0.6);
  --text-dim: rgba(255, 255, 255, 0.4);
  --text-faint: rgba(255, 255, 255, 0.25);

  /* Accents — used sparingly */
  --accent-indigo: #818cf8;
  --accent-cyan: #22d3ee;
  --accent-violet: #a78bfa;
  --accent-emerald: #34d399;
  --accent-rose: #fb7185;
  --accent-amber: #fbbf24;
  --accent-blue: #60a5fa;

  /* Semantic */
  --positive: #34d399;
  --negative: #fb7185;
  --warning: #fbbf24;
  --info: #60a5fa;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-2xl: 24px;
  --radius-3xl: 32px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-elevated: 0 16px 48px rgba(0, 0, 0, 0.4);
  --shadow-glow-indigo: 0 0 40px rgba(129, 140, 248, 0.08);
  --shadow-glow-cyan: 0 0 40px rgba(34, 211, 238, 0.08);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-deepest);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

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

a:hover {
  color: var(--accent-indigo);
}

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

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--glass-bg);
}

/* --- Layout --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-lg);
}

.container--narrow {
  max-width: 800px;
}

.container--wide {
  max-width: 1400px;
}

/* Centered full-screen layout */
.layout-centered {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: var(--space-lg);
  position: relative;
}

/* --- Typography --- */
.heading-xl {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.heading-lg {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.heading-md {
  font-size: clamp(1.125rem, 2vw, 1.5rem);
  font-weight: 600;
  line-height: 1.3;
}

.heading-sm {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
}

.text-body {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

.text-small {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--text-muted);
}

.text-xs {
  font-size: 0.75rem;
  line-height: 1.4;
  color: var(--text-dim);
}

.text-gradient {
  background: linear-gradient(135deg, var(--accent-indigo), var(--text-primary) 50%, var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-gradient-subtle {
  background: linear-gradient(180deg, var(--text-primary), rgba(255, 255, 255, 0.8));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* --- Utility Colors --- */
.text-muted { color: var(--text-muted); }
.text-dim { color: var(--text-dim); }
.text-positive { color: var(--positive); }
.text-negative { color: var(--negative); }
.text-warning { color: var(--warning); }

/* --- Spacing Utilities --- */
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }

/* --- Grid Utilities --- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(400px, 100%), 1fr));
  gap: var(--space-md);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: var(--space-md);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(200px, 100%), 1fr));
  gap: var(--space-md);
}

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

  html {
    scroll-behavior: auto;
  }

  .animate-float,
  .animate-pulse-subtle,
  .animate-shimmer {
    animation: none !important;
  }
}

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

@keyframes pulse-subtle {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

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

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

@keyframes scale-in {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  opacity: 0;
}

.animate-fade-in {
  animation: fadeIn 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  opacity: 0;
}

.animate-float {
  animation: float 8s ease-in-out infinite;
}

.animate-pulse-subtle {
  animation: pulse-subtle 3s ease-in-out infinite;
}

.animate-shimmer {
  background-size: 200% 100%;
  animation: shimmer 2s linear infinite;
}

.animate-spin {
  animation: spin 1.5s linear infinite;
}

.animate-scale-in {
  animation: scale-in 0.5s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  opacity: 0;
}

/* Staggered delays */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-400 { animation-delay: 400ms; }
.delay-500 { animation-delay: 500ms; }
.delay-600 { animation-delay: 600ms; }
.delay-700 { animation-delay: 700ms; }
.delay-800 { animation-delay: 800ms; }
.delay-1000 { animation-delay: 1000ms; }
.delay-1200 { animation-delay: 1200ms; }

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-deep);
}

::-webkit-scrollbar-thumb {
  background: var(--glass-border-strong);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* --- Selection --- */
::selection {
  background: rgba(129, 140, 248, 0.3);
  color: var(--text-primary);
}

/* --- Print --- */
@media print {
  body {
    background: #ffffff;
    color: #1a1a1a;
  }
  
  .glass-card,
  .glass-card-strong,
  .kpi-card {
    background: #f5f5f5;
    border: 1px solid #ddd;
    box-shadow: none;
    backdrop-filter: none;
  }

  .bg-effect,
  .geometric-shape,
  .sparkle-canvas,
  .wavy-canvas,
  .bg-gradient-overlay {
    display: none !important;
  }

  .text-gradient,
  .text-gradient-subtle {
    -webkit-text-fill-color: #1a1a1a;
    background: none;
  }

  a { color: #1a1a1a; }
}