:root {
  /* Colors */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b80;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-primary: #38bdf8;
  --accent-secondary: #818cf8;
  --border-color: #334155;
  
  /* Spacing */
  --container-width: 900px;
  --header-height: 70px;
  
  /* Fonts */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  line-height: 1.2;
}

h1 { font-size: 3rem; font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: 2rem; font-weight: 700; margin-bottom: 2rem; border-bottom: 2px solid var(--border-color); padding-bottom: 0.5rem; display: inline-block; }
h3 { font-size: 1.3rem; font-weight: 600; color: var(--accent-primary); margin-bottom: 0.5rem; }
h4 { font-size: 1rem; font-weight: 500; color: var(--text-secondary); margin-bottom: 1rem; }

p { color: var(--text-secondary); margin-bottom: 1rem; }

a { color: var(--accent-primary); text-decoration: none; transition: all 0.2s ease; }
a:hover { color: var(--accent-secondary); }

/* Layout */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

section {
  padding: 80px 0;
}

/* Header/Hero */
header {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding-top: 80px; /* Offset for potential fixed nav */
}

.hero-content {
  max-width: 600px;
  animation: fadeUp 0.8s ease-out;
}

.hero-title {
  font-size: 4rem;
  background: linear-gradient(to right, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 1rem;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--accent-primary);
  margin-bottom: 2rem;
}

.social-links {
  display: flex;
  gap: 20px;
  margin-top: 2rem;
}

.social-links a {
  padding: 10px 20px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-secondary);
  font-weight: 500;
}

.social-links a:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

/* Timeline/Experience */
.timeline-item {
  position: relative;
  padding-left: 30px;
  margin-bottom: 40px;
  border-left: 2px solid var(--border-color);
}

.timeline-item::after {
  content: '';
  position: absolute;
  left: -6px;
  top: 5px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent-primary);
  box-shadow: 0 0 0 4px var(--bg-primary);
}

.job-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.job-date {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-family: monospace;
}

.job-list {
  list-style: none;
}

.job-list li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.job-list li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent-secondary);
}

/* Projects Grid */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.card {
  background: var(--bg-card);
  padding: 30px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  transition: transform 0.2s, border-color 0.2s;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-primary);
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: auto;
  padding-top: 20px;
}

.tag {
  font-size: 0.8rem;
  padding: 4px 12px;
  border-radius: 20px;
  background: var(--bg-primary);
  color: var(--accent-primary);
  border: 1px solid var(--border-color);
}

/* Skills */
.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

.skill-pill {
  background: var(--bg-secondary);
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 500;
  border: 1px solid transparent;
}

.skill-pill:hover {
  border-color: var(--accent-primary);
  background: var(--bg-card);
}

/* Animations */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Utilities */
.text-highlight { color: var(--accent-primary); }
.mt-2 { margin-top: 2rem; }

/* Responsive */
@media (max-width: 768px) {
  h1 { font-size: 2.5rem; }
  .hero-title { font-size: 3rem; }
  .job-header { flex-direction: column; }
  section { padding: 40px 0; }
}