/* ============================================================
   Dark Mode Design System - Personal Website
   ============================================================
   Usage:
   - Import this file in any page: <link rel="stylesheet" href="../css/styles.css">
   - Add .matrix-bg class to a <canvas> element for the animation
   - Use semantic class names: .nav, .nav-link, .hero, .section, .card, etc.
   ============================================================ */

/* ---------- CSS Custom Properties (Design Tokens) ---------- */
:root {
  /* Backgrounds */
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.06);
  --bg-nav: rgba(10, 10, 10, 0.85);

  /* Text */
  --text-primary: #f0f0f0;
  --text-secondary: #a0a0a0;
  --text-muted: #666666;

  /* Accent - Matrix green with modern tint */
  --accent: #00ff88;
  --accent-dim: rgba(0, 255, 136, 0.15);
  --accent-glow: rgba(0, 255, 136, 0.4);

  /* Borders */
  --border: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(0, 255, 136, 0.3);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', monospace;

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

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
  color: #fff;
}

img {
  max-width: 100%;
  display: block;
}

/* ---------- Matrix Background Canvas ---------- */
.matrix-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  opacity: 0.25;
  pointer-events: none;
}

/* ---------- Layout Container ---------- */
.container {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition-base);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.nav-brand {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.5px;
}

.nav-brand:hover {
  color: #fff;
}

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

.nav-link {
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.3px;
  text-transform: uppercase;
  transition: color var(--transition-fast);
  position: relative;
}

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

.nav-link:hover,
.nav-link.active {
  color: var(--text-primary);
}

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

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px;
}

/* ---------- Hero Section ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-2xl) var(--space-md);
}

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

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-md);
  letter-spacing: -1.5px;
}

.hero-title .accent {
  color: var(--accent);
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  font-weight: 400;
}

.hero-cta {
  display: inline-flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  justify-content: center;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 8px;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  font-family: inherit;
}

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

.btn-primary:hover {
  background: #fff;
  color: #000;
  box-shadow: 0 0 30px var(--accent-glow);
}

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

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-accent);
}

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

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

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
  letter-spacing: -0.5px;
}

.section-description {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 600px;
}

/* ---------- Cards Grid ---------- */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-md);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: var(--space-lg);
  transition: all var(--transition-base);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

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

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.card-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

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

.about-avatar {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  margin: 0 auto;
}

.about-text h3 {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
}

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

/* ---------- Skills ---------- */
.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-md);
}

.skill-tag {
  padding: 6px 14px;
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  font-family: var(--font-mono);
}

/* ---------- Blog ---------- */
.posts-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: var(--space-lg);
  transition: all var(--transition-base);
  cursor: pointer;
}

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

.post-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.post-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--text-primary);
}

.post-card:hover .post-title {
  color: var(--accent);
}

.post-excerpt {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.5;
}

.post-tag {
  padding: 3px 10px;
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 500;
}

/* ---------- Blog Post ---------- */
.post-full {
  max-width: 750px;
  margin: 0 auto;
  padding: var(--space-2xl) 0;
}

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

.post-full-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.5px;
}

.post-full-meta {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-family: var(--font-mono);
}

.post-full-content {
  color: var(--text-secondary);
  line-height: 1.8;
}

.post-full-content h2 {
  color: var(--text-primary);
  font-size: 1.5rem;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

.post-full-content h3 {
  color: var(--text-primary);
  font-size: 1.25rem;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-xs);
}

.post-full-content p {
  margin-bottom: var(--space-md);
}

.post-full-content code {
  font-family: var(--font-mono);
  background: var(--bg-card);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--accent);
}

.post-full-content pre {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: var(--space-md);
  overflow-x: auto;
  margin-bottom: var(--space-md);
}

.post-full-content pre code {
  background: none;
  padding: 0;
  color: var(--text-primary);
}

.post-full-content blockquote {
  border-left: 3px solid var(--accent);
  padding-left: var(--space-md);
  margin: var(--space-md) 0;
  color: var(--text-secondary);
  font-style: italic;
}

.post-full-content ul,
.post-full-content ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

.post-full-content li {
  margin-bottom: var(--space-xs);
}

/* ---------- Back Button ---------- */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: var(--space-lg);
  transition: color var(--transition-fast);
}

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

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: var(--space-lg) 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg-nav);
    backdrop-filter: blur(20px);
    padding: var(--space-md);
    border-bottom: 1px solid var(--border);
  }

  .about-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

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

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

.fade-in {
  animation: fadeIn 0.6s ease forwards;
}

.fade-in-delay-1 { animation-delay: 0.1s; }
.fade-in-delay-2 { animation-delay: 0.2s; }
.fade-in-delay-3 { animation-delay: 0.3s; }
.fade-in-delay-4 { animation-delay: 0.4s; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}