/**
 * DESIGN SYSTEM - Extracted from David Martin Portfolio
 * Dark Theme with Glassmorphism Effects
 */

/* ========================================
   1. CSS VARIABLES (Design Tokens)
   ======================================== */
:root {
  /* Colors - Primary Palette */
  --color-bg-primary: #0f1729;
  --color-bg-secondary: #1a2332;
  --color-bg-card: rgba(26, 35, 50, 0.6);
  --color-bg-card-hover: rgba(26, 35, 50, 0.8);
  
  /* Accent Colors */
  --color-accent-blue: #4a9eff;
  --color-accent-cyan: #00d4ff;
  --color-accent-purple: #9333ea;
  --color-accent-red: #ef4444;
  
  /* Text Colors */
  --color-text-primary: #ffffff;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  
  /* Gradient Backgrounds */
  --gradient-hero: linear-gradient(135deg, #1e3a8a 0%, #312e81 50%, #1e293b 100%);
  --gradient-card: linear-gradient(135deg, rgba(30, 58, 138, 0.1) 0%, rgba(49, 46, 129, 0.1) 100%);
  --gradient-overlay: linear-gradient(180deg, transparent 0%, rgba(15, 23, 41, 0.9) 100%);
  
  /* Glass Effect */
  --glass-bg: rgba(26, 35, 50, 0.4);
  --glass-border: rgba(148, 163, 184, 0.1);
  --glass-blur: 20px;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* 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, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(74, 158, 255, 0.3);
  
  /* Typography */
  --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;
  
  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
  
  /* Z-Index */
  --z-base: 1;
  --z-dropdown: 10;
  --z-sticky: 100;
  --z-modal: 1000;
}

/* ========================================
   2. RESET & BASE STYLES
   ======================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

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

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

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

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

/* ========================================
   3. UTILITY CLASSES
   ======================================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

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

/* Flexbox 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(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }

/* Grid Utilities */
.grid {
  display: grid;
}

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

/* ========================================
   4. GLASS CARD COMPONENT
   ======================================== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(148, 163, 184, 0.3), transparent);
}

.glass-card:hover {
  background: var(--color-bg-card-hover);
  border-color: rgba(148, 163, 184, 0.2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

/* ========================================
   5. NAVIGATION BAR
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  background: rgba(15, 23, 41, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  padding: var(--spacing-sm) 0;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(15, 23, 41, 0.95);
  box-shadow: var(--shadow-md);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
}

.nav-menu {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
}

.nav-link {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
  background: rgba(74, 158, 255, 0.1);
}

/* ========================================
   6. HERO SECTION
   ======================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: var(--spacing-2xl) 0;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-hero);
  opacity: 0.9;
  z-index: -2;
}

.hero-bg-pattern {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(74, 158, 255, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(147, 51, 234, 0.15) 0%, transparent 50%);
  z-index: -1;
}

.hero-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.hero-image {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  border: 4px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), var(--shadow-glow);
  margin: 0 auto var(--spacing-lg);
  object-fit: cover;
}

.hero-title {
  font-size: var(--text-5xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, #ffffff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
}

/* ========================================
   7. STATS CARDS
   ======================================== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.stat-card {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-card);
  opacity: 0.5;
  z-index: -1;
}

.stat-card:hover {
  transform: translateY(-8px);
  border-color: rgba(148, 163, 184, 0.3);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-value {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.stat-value span {
  font-size: var(--text-2xl);
  color: var(--color-text-secondary);
  margin-left: var(--spacing-xs);
}

.stat-description {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ========================================
   8. TECH BADGES
   ======================================== */
.tech-badges {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  justify-content: center;
  margin: var(--spacing-xl) 0;
}

.tech-badge {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-primary);
  transition: all var(--transition-fast);
}

.tech-badge:hover {
  background: rgba(74, 158, 255, 0.1);
  border-color: var(--color-accent-blue);
  transform: scale(1.05);
}

.tech-icon {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ========================================
   9. PROJECT CARDS
   ======================================== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.project-card {
  background: var(--color-bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-base);
  position: relative;
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(148, 163, 184, 0.3);
}

.project-image {
  width: 100%;
  height: 220px;
  object-fit: cover;
  position: relative;
}

.project-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-overlay);
  opacity: 0;
  transition: opacity var(--transition-base);
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-card:hover .project-overlay {
  opacity: 1;
}

.project-content {
  padding: var(--spacing-lg);
}

.project-title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
}

.project-description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.project-tag {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  padding: 4px 8px;
  background: rgba(148, 163, 184, 0.1);
  border-radius: var(--radius-sm);
}

.project-tag::before {
  content: '✓';
  color: var(--color-accent-blue);
}

/* ========================================
   10. BUTTONS
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-accent-blue);
  color: var(--color-text-primary);
  box-shadow: 0 4px 16px rgba(74, 158, 255, 0.3);
}

.btn-primary:hover {
  background: #3b82f6;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(74, 158, 255, 0.4);
}

.btn-secondary {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--color-text-primary);
}

.btn-secondary:hover {
  background: var(--color-bg-card-hover);
  border-color: rgba(148, 163, 184, 0.3);
}

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

.btn-ghost:hover {
  background: rgba(74, 158, 255, 0.1);
  color: var(--color-text-primary);
}

/* ========================================
   11. SECTION STYLING
   ======================================== */
.section {
  padding: var(--spacing-2xl) 0;
}

.section-title {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
}

/* ========================================
   12. RESPONSIVE BREAKPOINTS
   ======================================== */
@media (max-width: 1024px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2rem;
  }
  
  .hero-title {
    font-size: var(--text-4xl);
  }
  
  .stats-grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
  }
  
  .hero {
    min-height: auto;
    padding: calc(60px + var(--spacing-xl)) 0 var(--spacing-xl);
  }
  
  .hero-title {
    font-size: var(--text-3xl);
  }
  
  .hero-tagline {
    font-size: var(--text-lg);
  }
  
  .nav-menu {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
  
  .stats-grid,
  .projects-grid {
    grid-template-columns: 1fr;
  }
  
  .stat-value {
    font-size: var(--text-3xl);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .hero-image {
    width: 140px;
    height: 140px;
  }
  
  .glass-card,
  .stat-card {
    padding: var(--spacing-md);
  }
}

/* ========================================
   13. ANIMATIONS
   ======================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

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

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

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out forwards;
}

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

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

/* Stagger animations */
.animate-delay-100 { animation-delay: 0.1s; }
.animate-delay-200 { animation-delay: 0.2s; }
.animate-delay-300 { animation-delay: 0.3s; }
.animate-delay-400 { animation-delay: 0.4s; }