/* ===== CSS VARIABLES & DESIGN SYSTEM ===== */
:root {
  /* Colors - Dark Mode Primary */
  --bg: #0B0C10;
  --surface: #111218;
  --surface-elevated: #1A1B23;
  --text: #EAEAF1;
  --text-muted: #A4A6B3;
  --text-subtle: #6B7280;
  --brand: #8CF3FF;
  --brand-2: #FFB86B;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.12);
  --glass: rgba(255, 255, 255, 0.03);
  --glass-border: rgba(255, 255, 255, 0.1);
  
  /* Semantic Colors */
  --success: #10B981;
  --warning: #F59E0B;
  --error: #EF4444;
  --info: var(--brand);
  
  /* Spacing Scale */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  --space-32: 8rem;     /* 128px */
  
  /* Typography Scale */
  --font-size-xs: 0.75rem;     /* 12px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;    /* 18px */
  --font-size-xl: 1.25rem;     /* 20px */
  --font-size-2xl: 1.5rem;     /* 24px */
  --font-size-3xl: 1.875rem;   /* 30px */
  --font-size-4xl: 2.25rem;    /* 36px */
  --font-size-5xl: 3rem;       /* 48px */
  --font-size-6xl: 3.75rem;    /* 60px */
  --font-size-7xl: 4.5rem;     /* 72px */
  
  /* Font Families */
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Space Grotesk', 'Inter', system-ui, sans-serif;
  
  /* Container & Layout */
  --container-max: 1200px;
  --container-padding: var(--space-6);
  --border-radius: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-glow: 0 0 25px rgba(140, 243, 255, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* Light Mode */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #FFFFFF;
    --surface: #F8FAFC;
    --surface-elevated: #FFFFFF;
    --text: #1E293B;
    --text-muted: #475569;
    --text-subtle: #94A3B8;
    --line: rgba(0, 0, 0, 0.08);
    --line-strong: rgba(0, 0, 0, 0.12);
    --glass: rgba(255, 255, 255, 0.8);
    --glass-border: rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 25px rgba(140, 243, 255, 0.25);
  }
}

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

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

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

/* Respect user motion preferences */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.025em;
}

h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.05em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
}

h3 {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
}

h4 {
  font-size: clamp(1.25rem, 2.5vw, 1.875rem);
}

p {
  margin-bottom: var(--space-4);
  font-size: var(--font-size-base);
  line-height: 1.7;
}

.text-large {
  font-size: clamp(1.125rem, 2vw, 1.25rem);
  line-height: 1.6;
}

.text-glow {
  color: var(--brand);
  text-shadow: 0 0 20px rgba(140, 243, 255, 0.5);
}

/* ===== LAYOUT SYSTEM ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.grid {
  display: grid;
  gap: var(--space-6);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Section Spacing */
.section {
  padding: var(--space-20) 0;
}

.section-lg {
  padding: var(--space-32) 0;
}

/* ===== COMPONENT STYLES ===== */

/* Glass Card */
.glass-card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: all var(--transition-base);
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
  border-color: var(--brand);
}

/* Surface Card */
.surface-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--border-radius-lg);
  padding: var(--space-8);
  transition: all var(--transition-base);
}

.surface-card:hover {
  border-color: var(--line-strong);
  box-shadow: var(--shadow-lg);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3) var(--space-6);
  border: none;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--font-size-base);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: var(--bg);
  box-shadow: 0 4px 15px rgba(140, 243, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(140, 243, 255, 0.4);
}

.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line-strong);
}

.btn-secondary:hover {
  background: var(--surface);
  border-color: var(--brand);
  color: var(--brand);
}

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

/* Magnetic button effect */
.btn-magnetic {
  transition: transform var(--transition-fast) ease-out;
}

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

/* ===== UTILITY CLASSES ===== */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-100 { opacity: 1; }

.pointer-events-none { pointer-events: none; }
.pointer-events-auto { pointer-events: auto; }

/* Aspect Ratios */
.aspect-video {
  aspect-ratio: 16 / 9;
}

.aspect-square {
  aspect-ratio: 1 / 1;
}

/* ===== LOADING STATES ===== */
.loading-shimmer {
  background: linear-gradient(
    90deg,
    var(--surface) 0%,
    var(--surface-elevated) 50%,
    var(--surface) 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

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

/* ===== SCROLL PROGRESS BAR ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  transform-origin: 0% 50%;
  z-index: var(--z-fixed);
}

/* ===== ANIMATION HELPERS ===== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 0.8s ease-out forwards;
}

.animate-slide-up {
  opacity: 0;
  transform: translateY(30px);
  animation: slideUp 0.8s ease-out forwards;
}

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

@keyframes slideUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Stagger animation delays */
.animate-stagger-1 { animation-delay: 0.1s; }
.animate-stagger-2 { animation-delay: 0.2s; }
.animate-stagger-3 { animation-delay: 0.3s; }
.animate-stagger-4 { animation-delay: 0.4s; }
.animate-stagger-5 { animation-delay: 0.5s; }
.animate-stagger-6 { animation-delay: 0.6s; }