/**
 * Modern Geeky Design System
 * A tech-savvy, interactive design with dark mode support
 */

/* ============================================================================
   CSS VARIABLES - DESIGN TOKENS
   ============================================================================ */

:root {
  /* Colors - Light Mode (Cyberpunk/Terminal inspired) */
  --bg-primary: #0a0e27;
  --bg-secondary: #151932;
  --bg-tertiary: #1e2440;
  --bg-elevated: #252b4a;

  --text-primary: #e4e4e7;
  --text-secondary: #a1a1aa;
  --text-tertiary: #71717a;

  --accent-primary: #00ff9f;      /* Matrix green */
  --accent-secondary: #00d9ff;    /* Cyan */
  --accent-tertiary: #ff006e;     /* Hot pink */
  --accent-warning: #ffbe0b;      /* Yellow */

  --border-color: #27293d;
  --border-accent: #00ff9f33;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #00ff9f 0%, #00d9ff 100%);
  --gradient-secondary: linear-gradient(135deg, #ff006e 0%, #ffbe0b 100%);
  --gradient-dark: linear-gradient(180deg, #0a0e27 0%, #1e2440 100%);

  /* Shadows & Glows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --glow-green: 0 0 20px rgba(0, 255, 159, 0.5);
  --glow-cyan: 0 0 20px rgba(0, 217, 255, 0.5);
  --glow-pink: 0 0 20px rgba(255, 0, 110, 0.5);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Fira Code', 'JetBrains Mono', 'Consolas', monospace;
  --font-display: 'Space Grotesk', var(--font-sans);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

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

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

  /* Z-index */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal: 400;
  --z-popover: 500;
  --z-tooltip: 600;
}

/* Light Mode Override */
[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-elevated: #ffffff;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #94a3b8;

  --accent-primary: #0ea5e9;
  --accent-secondary: #8b5cf6;
  --accent-tertiary: #ec4899;
  --accent-warning: #f59e0b;

  --border-color: #e2e8f0;
  --border-accent: #0ea5e933;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --glow-green: 0 0 20px rgba(14, 165, 233, 0.3);
  --glow-cyan: 0 0 20px rgba(139, 92, 246, 0.3);
  --glow-pink: 0 0 20px rgba(236, 72, 153, 0.3);
}

/* ============================================================================
   RESET & BASE STYLES
   ============================================================================ */

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

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

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: background var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
}

/* Selection */
::selection {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 12px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--accent-primary);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-secondary);
}

/* ============================================================================
   TYPOGRAPHY
   ============================================================================ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

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

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

code {
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  font-size: 0.9em;
  color: var(--accent-primary);
}

pre {
  font-family: var(--font-mono);
  background: var(--bg-secondary);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: var(--space-lg);
  border: 1px solid var(--border-color);
}

pre code {
  background: none;
  padding: 0;
}

/* ============================================================================
   LAYOUT
   ============================================================================ */

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

.container-fluid {
  width: 100%;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--space-2xl);
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--gradient-primary);
  margin: var(--space-md) auto 0;
  border-radius: var(--radius-full);
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--space-lg);
}

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

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

/* Flex Utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

/* ============================================================================
   COMPONENTS
   ============================================================================ */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--bg-primary);
  box-shadow: var(--glow-green);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-green), var(--shadow-lg);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--border-accent);
}

.btn-secondary:hover {
  background: var(--bg-elevated);
  border-color: var(--accent-primary);
}

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

.btn-outline:hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

/* Cards */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: left;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent-primary);
}

.card:hover::before {
  transform: scaleX(1);
}

.card-title {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
}

.card-content {
  color: var(--text-secondary);
}

/* Tags/Badges */
.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.875rem;
  font-weight: 500;
  background: var(--bg-tertiary);
  color: var(--accent-primary);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.tag:hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
  transform: scale(1.05);
}

.tag-active {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

/* Loading Skeleton */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--bg-tertiary) 0%,
    var(--bg-elevated) 50%,
    var(--bg-tertiary) 100%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

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

/* ============================================================================
   ANIMATIONS
   ============================================================================ */

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

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

@keyframes glow {
  0%, 100% {
    box-shadow: var(--glow-green);
  }
  50% {
    box-shadow: var(--glow-cyan);
  }
}

/* Animation Utilities */
.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

.animate-slide-in-left {
  animation: slideInLeft 0.6s ease-out;
}

.animate-slide-in-right {
  animation: slideInRight 0.6s ease-out;
}

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

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

/* ============================================================================
   UTILITY CLASSES
   ============================================================================ */

/* Text Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-accent { color: var(--accent-primary); }

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

/* Font Weights */
.font-light { font-weight: 300; }
.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

/* Font Families */
.font-mono { font-family: var(--font-mono); }
.font-display { font-family: var(--font-display); }

/* Spacing */
.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); }

.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); }

.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }

/* Display */
.block { display: block; }
.inline-block { display: inline-block; }
.hidden { display: none; }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }

/* ============================================================================
   RESPONSIVE
   ============================================================================ */

@media (max-width: 768px) {
  :root {
    font-size: 14px;
  }

  .container {
    padding: 0 var(--space-md);
  }

  .section {
    padding: var(--space-2xl) 0;
  }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.5rem; }
}

@media (max-width: 480px) {
  .btn {
    width: 100%;
    justify-content: center;
  }
}