:root {
  /* Colors - Refined Neutral Palette */
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --border-color: #e5e7eb;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

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

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --max-width: 1100px;
}

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

html {
  scroll-behavior: smooth;
}

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

h1, h2, h3, h4 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.2;
}

a {
  text-decoration: none;
  color: inherit;
  transition: all 0.2s ease;
}

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* Navigation */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  height: 70px;
  display: flex;
  align-items: center;
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.logo span {
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: var(--space-lg);
  align-items: center;
}

.nav-links a {
  font-weight: 500;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

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

.theme-toggle {
  background: var(--bg-tertiary);
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
}

/* Hero Section */
.hero {
  padding: var(--space-2xl) 0;
  min-height: 70vh;
  display: flex;
  align-items: center;
}

.hero-content {
  max-width: 700px;
}

.hero-tagline {
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.85rem;
  margin-bottom: var(--space-sm);
  display: block;
}

.hero h1 {
  font-size: clamp(2.5rem, 8vw, 4rem);
  margin-bottom: var(--space-md);
  letter-spacing: -1px;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  max-width: 600px;
}

.cta-group {
  display: flex;
  gap: var(--space-sm);
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  font-weight: 600;
  transition: all 0.2s;
  cursor: pointer;
}

.btn-primary {
  background-color: var(--accent);
  color: white;
  border: none;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
}

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

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
}

/* Sections General */
section {
  padding: var(--space-2xl) 0;
}

.section-header {
  margin-bottom: var(--space-xl);
}

.section-header h2 {
  font-size: 2.25rem;
  margin-bottom: var(--space-xs);
  position: relative;
  display: inline-block;
}

.section-header h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 40px;
  height: 4px;
  background: var(--accent);
  border-radius: 2px;
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-top: var(--space-sm);
}

/* About & Skills */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: start;
}

.bio p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

.skills-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: var(--space-md);
}

.skill-tag {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* Projects */
.filter-bar {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.filter-btn {
  background: none;
  border: none;
  padding: 0.5rem 1rem;
  cursor: pointer;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.9rem;
}

.filter-btn.active {
  color: var(--accent);
  background: rgba(37, 99, 235, 0.1);
  border-radius: 4px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}

.project-card {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--card-shadow-hover);
}

.placeholder-image {
  width: 100%;
  aspect-ratio: 16/9;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.placeholder-image::before {
  content: attr(data-label);
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.9rem;
}

.project-info {
  padding: var(--space-md);
}

.project-category {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: var(--space-xs);
  display: block;
}

.project-info h3 {
  margin-bottom: var(--space-xs);
  font-size: 1.25rem;
}

.project-info p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: var(--space-md);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.project-footer {
  display: flex;
  gap: var(--space-sm);
}

.project-link {
  font-size: 0.85rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--text-primary);
}

.project-link:hover {
  color: var(--accent);
}

/* Contact */
.contact-container {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--space-2xl);
}

.contact-info h3 {
  margin-bottom: var(--space-md);
}

.contact-info p {
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

.contact-method {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.contact-form {
  display: grid;
  gap: var(--space-md);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-control {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background: var(--bg-secondary);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.form-control:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--bg-primary);
}

textarea.form-control {
  min-height: 150px;
  resize: vertical;
}

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

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

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

.social-link {
  color: var(--text-secondary);
}

.social-link:hover {
  color: var(--accent);
}

.copyright {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .about-grid, .contact-container {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .nav-links {
    display: none; /* In a real app, this would be a hamburger menu */
  }

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

  .hero h1 {
    font-size: 2.5rem;
  }

  .footer-content {
    flex-direction: column;
    gap: var(--space-lg);
    text-align: center;
  }
}

/* Blog Specific Styles */
.blog-header {
  padding: var(--space-2xl) 0 var(--space-xl);
  text-align: center;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.blog-post-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.blog-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  gap: 12px;
}

.blog-title {
  font-size: 1.5rem;
  margin: 0.5rem 0;
}

.blog-excerpt {
  color: var(--text-secondary);
  font-size: 1rem;
}

.read-more {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.95rem;
  margin-top: auto;
}

.nav-link-active {
  color: var(--accent) !important;
}