/* ============================================
   GEROL PETRUZELLA - MODERN DESIGN SYSTEM
   Vanilla CSS, Tech-Forward Aesthetic
   ============================================ */

/* ========== CSS Custom Properties ========== */
:root {
  /* Color Palette - Modern Tech with Deep Purple Accent */
  --color-navy-dark: #0a1628;
  --color-navy: #1a2332;
  --color-slate-dark: #2d3748;
  --color-slate: #4a5568;
  --color-slate-light: #718096;
  --color-gray-100: #f7fafc;
  --color-gray-200: #edf2f7;
  --color-gray-300: #e2e8f0;

  --color-purple: #6b46c1;
  --color-purple-dark: #553c9a;
  --color-purple-light: #9f7aea;
  --color-purple-glow: rgba(107, 70, 193, 0.15);

  --color-text-primary: #1a202c;
  --color-text-secondary: #4a5568;
  --color-text-tertiary: #718096;

  /* Typography */
  --font-system: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;

  /* Layout */
  --max-width-prose: 65ch;
  --max-width-container: 1280px;
  --max-width-narrow: 800px;

  /* Effects */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --color-gray-100: #1a202c;
  --color-gray-200: #2d3748;
  --color-gray-300: #4a5568;

  --color-text-primary: #f7fafc;
  --color-text-secondary: #e2e8f0;
  --color-text-tertiary: #cbd5e0;

  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-system);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-gray-100);
  transition: background-color var(--transition-base), color var(--transition-base);
}

[data-theme="dark"] body {
  background-color: var(--color-navy-dark);
}

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-4);
  color: var(--color-text-primary);
}

h1 {
  font-size: var(--font-size-5xl);
  letter-spacing: -0.025em;
  margin-bottom: var(--space-6);
}

h2 {
  font-size: var(--font-size-4xl);
  letter-spacing: -0.02em;
}

h3 {
  font-size: var(--font-size-3xl);
  letter-spacing: -0.015em;
}

h4 {
  font-size: var(--font-size-2xl);
}

h5 {
  font-size: var(--font-size-xl);
}

h6 {
  font-size: var(--font-size-lg);
}

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

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

a:hover {
  color: var(--color-purple-light);
}

a:focus-visible {
  outline: 2px solid var(--color-purple);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ========== Layout Components ========== */

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(26, 35, 50, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(107, 70, 193, 0.2);
  transition: background-color var(--transition-base);
}

[data-theme="dark"] .nav {
  background: rgba(10, 22, 40, 0.95);
}

.nav-container {
  max-width: var(--max-width-container);
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: #ffffff;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-brand-dot {
  width: 8px;
  height: 8px;
  background: var(--color-purple);
  border-radius: 50%;
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.6;
    transform: scale(1.1);
  }
}

.nav-links {
  display: flex;
  gap: var(--space-6);
  list-style: none;
}

.nav-link {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-purple);
  transition: width var(--transition-base);
}

.nav-link:hover {
  color: #ffffff;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-link.active {
  color: #ffffff;
}

/* Dark Mode Toggle */
.theme-toggle {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.8);
  padding: var(--space-2) var(--space-3);
  border-radius: 6px;
  cursor: pointer;
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--color-purple);
  color: #ffffff;
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #ffffff;
  padding: var(--space-2);
  border-radius: 6px;
  cursor: pointer;
  font-size: var(--font-size-lg);
}

@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-navy);
    flex-direction: column;
    padding: var(--space-4);
    gap: var(--space-2);
    border-bottom: 1px solid rgba(107, 70, 193, 0.2);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-link::after {
    display: none;
  }
}

/* Container */
.container {
  max-width: var(--max-width-container);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Hero Section */
.hero {
  padding: var(--space-20) 0 var(--space-16);
  text-align: center;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  margin-bottom: var(--space-4);
  background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-slate) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.3;
  padding-bottom: 0.1em;
  display: inline-block;
}

[data-theme="dark"] .hero-title {
  background: linear-gradient(135deg, #ffffff 0%, var(--color-purple-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.3;
  padding-bottom: 0.1em;
  display: inline-block;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  max-width: 700px;
  margin: 0 auto var(--space-8);
  line-height: 1.7;
}

.hero-tagline {
  font-size: var(--font-size-lg);
  color: var(--color-text-tertiary);
  max-width: 600px;
  margin: 0 auto var(--space-8);
  font-weight: 400;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  font-family: var(--font-system);
}

.btn-primary {
  background: var(--color-purple);
  color: #ffffff;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: var(--color-purple-dark);
  box-shadow: var(--shadow-lg);
  transform: translateY(-1px);
  color: #ffffff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-purple);
  border: 2px solid var(--color-purple);
}

.btn-secondary:hover {
  background: var(--color-purple-glow);
  color: var(--color-purple-dark);
}

.btn-group {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  justify-content: center;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-8);
  margin: var(--space-12) 0;
}

.card {
  background: #ffffff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  border: 1px solid var(--color-gray-300);
}

[data-theme="dark"] .card {
  background: var(--color-navy);
  border-color: var(--color-slate-dark);
}

.card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: var(--color-purple);
}

.card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: var(--color-gray-200);
}

.card-body {
  padding: var(--space-6);
}

.card-title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-3);
  color: var(--color-text-primary);
}

.card-text {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  line-height: 1.6;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-4);
}

.card-tag {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
}

/* Sections */
.section {
  padding: var(--space-16) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-4);
}

.section-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Stats/Highlights */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-8);
  margin: var(--space-12) 0;
}

.stat {
  text-align: center;
  padding: var(--space-6);
}

.stat-value {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--color-purple);
  margin-bottom: var(--space-2);
}

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

/* List Groups */
.list-clean {
  list-style: none;
  padding: 0;
}

.list-item {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-gray-300);
  transition: background-color var(--transition-fast);
}

[data-theme="dark"] .list-item {
  border-bottom-color: var(--color-slate-dark);
}

.list-item:hover {
  background-color: var(--color-purple-glow);
}

.list-item:last-child {
  border-bottom: none;
}

/* Badge */
.badge {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: 12px;
  background: var(--color-purple-glow);
  color: var(--color-purple-dark);
}

/* Footer */
.footer {
  background: var(--color-navy);
  color: rgba(255, 255, 255, 0.8);
  padding: var(--space-12) 0 var(--space-6);
  margin-top: var(--space-20);
}

[data-theme="dark"] .footer {
  background: var(--color-navy-dark);
  border-top: 1px solid var(--color-slate-dark);
}

.footer-content {
  max-width: var(--max-width-container);
  margin: 0 auto;
  padding: 0 var(--space-6);
  text-align: center;
}

.footer-personal {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: var(--space-4);
  font-style: italic;
}

.footer-links {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--space-4);
}

.footer-link {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--color-purple-light);
}

.footer-copyright {
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.5);
  margin-top: var(--space-6);
}

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

/* Skip to main content */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-purple);
  color: white;
  padding: var(--space-2) var(--space-4);
  text-decoration: none;
  z-index: 1000;
}

.skip-link:focus {
  top: 0;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.25rem;
    --font-size-4xl: 1.875rem;
    --font-size-3xl: 1.5rem;
  }

  .hero {
    padding: var(--space-12) 0 var(--space-10);
  }

  .section {
    padding: var(--space-10) 0;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .btn-group {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}

/* Print styles */
@media print {
  .nav,
  .theme-toggle,
  .btn,
  .footer {
    display: none;
  }
}