:root {
  /* Premium Dark Palette */
  --bg-body: #0a0a0a;
  --bg-card: #171717;
  --bg-card-hover: #262626;
  --text-primary: #ededed;
  --text-secondary: #a1a1aa;
  --text-accent: #38bdf8; /* Sky 400 */
  --border-subtle: #404040;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  
  /* Spacing */
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;
  
  /* Animation */
  --transition-fast: 0.2s ease;
  --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  font-weight: 700;
  color: #fff;
}

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

a:hover {
  color: #7dd3fc;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Sections */
section {
  padding: var(--spacing-xl) 0;
}

/* Hero */
.hero {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
}

.hero h1 {
  font-size: clamp(3rem, 5vw, 5rem);
  margin-bottom: var(--spacing-md);
  background: linear-gradient(to right, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--text-accent);
  margin-bottom: var(--spacing-lg);
  font-weight: 500;
}

.hero-text {
  max-width: 600px;
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: var(--spacing-lg);
}

.cta-group {
  display: flex;
  gap: var(--spacing-md);
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-primary {
  background-color: var(--text-accent);
  color: #000;
}

.btn-primary:hover {
  background-color: #7dd3fc; /* Sky 300 */
  transform: translateY(-2px);
}

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

.btn-ghost:hover {
  border-color: var(--text-accent);
  background-color: rgba(56, 189, 248, 0.1);
}

/* Timeline (About Me) */
.timeline {
  position: relative;
  padding-left: 2rem;
  border-left: 2px solid var(--border-subtle);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--spacing-xl);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.6rem;
  top: 0.4rem;
  width: 1rem;
  height: 1rem;
  background-color: var(--bg-body);
  border: 2px solid var(--text-accent);
  border-radius: 50%;
}

.timeline-date {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  font-family: monospace;
}

.timeline-title {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.timeline-company {
  color: var(--text-accent);
  font-weight: 600;
  margin-bottom: 1rem;
}

.timeline-content ul {
  list-style-type: none;
}

.timeline-content li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

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

/* Grid Layouts */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  padding: var(--spacing-lg);
  border-radius: 12px;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--text-accent);
  background: var(--bg-card-hover);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
}

.card h3 {
  margin-bottom: var(--spacing-sm);
  color: #fff;
}

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

/* Flagship Projects */
.project-item {
  margin-bottom: 4rem;
}

.project-header {
  margin-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: var(--spacing-md);
}

.project-title {
  font-size: 2rem;
  color: white;
}

.project-meta {
  color: var(--text-accent);
  font-family: monospace;
}

.project-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
}

@media (max-width: 768px) {
  .project-grid {
    grid-template-columns: 1fr;
  }
}

.project-block h4 {
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.project-block p, .project-block ul {
  font-size: 1rem;
  color: var(--text-primary);
}

.stat-highlight {
  color: var(--text-accent);
  font-weight: bold;
}

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  background: rgba(255,255,255,0.05);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  border: 1px solid transparent;
}

.tag:hover {
  border-color: var(--text-accent);
  color: #fff;
}

/* Footer */
footer {
  text-align: center;
  padding: 4rem 0;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-subtle);
  margin-top: 4rem;
}

/* Animation Utilities */
.fade-in-section {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  will-change: opacity, visibility;
}

.fade-in-section.is-visible {
  opacity: 1;
  transform: none;
}