/* ============================================
   NEXUS DESIGN SYSTEM
   Modern, Alive, Responsive Interface
   ============================================ */

/* -------------------- CSS VARIABLES -------------------- */
:root {
  /* Primary Colors */
  --primary: #667eea;
  --primary-dark: #5568d3;
  --primary-light: #8b9ff5;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-warning: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  --gradient-danger: linear-gradient(135deg, #f857a6 0%, #ff5858 100%);
  --gradient-info: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
  
  /* Semantic Colors */
  --success: #00f2fe;
  --warning: #fee140;
  --danger: #ff5858;
  --info: #a8edea;
  
  /* Neutral Colors */
  --dark: #1a1a2e;
  --dark-light: #16213e;
  --gray: #6c757d;
  --gray-light: #e9ecef;
  --white: #ffffff;
  
  /* Background Colors */
  --bg-primary: #f8f9fa;
  --bg-dark: #0f0f1e;
  --bg-card: rgba(255, 255, 255, 0.95);
  --bg-card-dark: rgba(26, 26, 46, 0.95);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-heading: 'Outfit', 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Font Sizes (Fluid Typography) */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.5rem);
  --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.875rem);
  --text-2xl: clamp(1.5rem, 1.3rem + 1vw, 2.25rem);
  --text-3xl: clamp(1.875rem, 1.5rem + 1.875vw, 3rem);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
  --shadow-xl: 0 12px 48px rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Z-Index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --bg-primary: var(--bg-dark);
  --bg-card: var(--bg-card-dark);
  --text-primary: var(--white);
  --text-secondary: var(--gray-light);
  --dark: #ffffff;
  --white: #1a1a2e;
}

/* -------------------- BASE STYLES -------------------- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--dark);
  background: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-base);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

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

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

a:hover {
  color: var(--primary-dark);
}

/* -------------------- UTILITY CLASSES -------------------- */
.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glassmorphism {
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.shadow-soft {
  box-shadow: var(--shadow-md);
}

.shadow-hover {
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.shadow-hover:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

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

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

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

@keyframes shimmer {
  0% {
    background-position: -1000px 0;
  }
  100% {
    background-position: 1000px 0;
  }
}

.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

.animate-slide-in {
  animation: slideInRight 0.5s ease-out;
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Stagger children animations */
.stagger-children > * {
  animation: fadeIn 0.6s ease-out;
  opacity: 0;
  animation-fill-mode: forwards;
}

.stagger-children > *:nth-child(1) { animation-delay: 0.1s; }
.stagger-children > *:nth-child(2) { animation-delay: 0.2s; }
.stagger-children > *:nth-child(3) { animation-delay: 0.3s; }
.stagger-children > *:nth-child(4) { animation-delay: 0.4s; }
.stagger-children > *:nth-child(5) { animation-delay: 0.5s; }
.stagger-children > *:nth-child(6) { animation-delay: 0.6s; }

/* -------------------- RESPONSIVE -------------------- */
@media (max-width: 768px) {
  :root {
    --spacing-lg: 1rem;
    --spacing-xl: 1.5rem;
    --spacing-2xl: 2rem;
  }
}

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