:root {
  /* Color Palette - Modern Data/AI Theme */
  --bg-primary: #0a0a0c;
  --bg-secondary: #141418;
  --bg-tertiary: #1c1c22;
  --accent-primary: #6366f1; /* Indigo */
  --accent-secondary: #22d3ee; /* Cyan */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: #2d2d35;
  --glass-bg: rgba(20, 20, 24, 0.8);
  --glass-border: rgba(255, 255, 255, 0.05);

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  /* Typography */
  --font-display: 'Inter', system-ui, -apple-system, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

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

/* Layout */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
}

section {
  margin-top: var(--space-xl);
  padding-bottom: var(--space-xl);
}

main > :first-child {
  margin-top: 0;
}

/* Typography */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* Hero Section */
.hero {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border-color);
}

.hero::before {
  content: '';
  position: absolute;
  top: -10%;
  right: -10%;
  width: 50%;
  height: 80%;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
  z-index: -1;
}

.hero-name {
  font-size: clamp(3rem, 10vw, 6rem);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
}

.hero-tagline {
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  color: var(--text-secondary);
  max-width: 800px;
  margin-bottom: var(--space-lg);
}

.hero-contact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.5rem 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 100px;
  transition: all 0.3s ease;
}

.contact-item:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
  transform: translateY(-2px);
}

/* Cards & Components */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 1rem;
  padding: var(--space-lg);
  transition: transform 0.3s ease, border-color 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card:hover {
  border-color: var(--accent-primary);
}

.section-title {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-primary);
  margin-bottom: var(--space-sm);
  display: block;
}

.section-heading {
  font-size: 2.5rem;
  margin-bottom: var(--space-lg);
}

/* Grid Layouts */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--space-md);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}

/* Skills Grid */
.skills-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-md);
}

.skill-category {
  padding: var(--space-md);
  background: var(--bg-tertiary);
  border-radius: 0.75rem;
}

.skill-category h4 {
  margin-bottom: var(--space-sm);
  color: var(--accent-secondary);
  font-size: 1rem;
}

.skill-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-tag {
  background: var(--bg-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  font-size: 0.8rem;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}

/* Projects */
.project-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.project-title {
  font-size: 1.5rem;
  color: var(--text-primary);
}

.project-meta {
  color: var(--accent-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.project-bullets {
  list-style: none;
}

.project-bullets li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.project-bullets li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
}

/* Education & Experience */
.timeline-item {
  position: relative;
  padding-left: var(--space-lg);
  border-left: 1px solid var(--border-color);
  padding-bottom: var(--space-lg);
}

.timeline-item::after {
  content: '';
  position: absolute;
  left: -5px;
  top: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent-primary);
  box-shadow: 0 0 10px var(--accent-primary);
}

.timeline-date {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.timeline-title {
  font-size: 1.25rem;
  margin: 0.5rem 0;
}

.timeline-sub {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

/* Certification badges */
.cert-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.cert-badge {
  background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-secondary));
  border: 1px solid var(--border-color);
  padding: 1rem;
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
}

.cert-icon {
  width: 40px;
  height: 40px;
  background: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  flex-shrink: 0;
}

/* Footer */
footer {
  margin-top: var(--space-2xl);
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--border-color);
  text-align: center;
  color: var(--text-muted);
}

.placeholder-image {
  width: 100%;
  height: 200px;
  background-color: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  position: relative;
  overflow: hidden;
}

.placeholder-image::after {
  content: attr(data-label);
  color: var(--text-muted);
  font-size: 0.8rem;
  text-transform: uppercase;
}

/* Nav */
nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
}

.nav-links {
  display: flex;
  gap: var(--space-md);
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  transition: color 0.3s ease;
}

.nav-links a:hover {
  color: var(--accent-primary);
}

@media (max-width: 768px) {
  .hero-contact {
    flex-direction: column;
  }
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
  .nav-links {
    display: none;
  }
}