:root {
  /* Colors - Dark Theme (Default) */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-primary: #3b82f6; /* Blue for intellect */
  --accent-secondary: #10b981; /* Green for growth/sports */
  --accent-tertiary: #f59e0b; /* Orange for energy */
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  
  /* Typography & Spacing */
  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 48px;
  --max-width: 1200px;
  --nav-height: 70px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0, 0, 0, 0.05);
  --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.05);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 20px);
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Animated Background Mesh */
.bg-mesh {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: float 20s infinite ease-in-out;
}

.blob-1 {
  width: 400px;
  height: 400px;
  background: var(--accent-primary);
  top: -100px;
  right: -100px;
  animation-delay: 0s;
}

.blob-2 {
  width: 300px;
  height: 300px;
  background: var(--accent-secondary);
  bottom: 10%;
  left: -50px;
  animation-delay: -5s;
}

.blob-3 {
  width: 250px;
  height: 250px;
  background: var(--accent-tertiary);
  top: 40%;
  right: 20%;
  animation-delay: -10s;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -50px) scale(1.1); }
  66% { transform: translate(-20px, 20px) scale(0.9); }
}

/* Navigation */
.top-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-sm);
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  transition: all 0.3s ease;
}

.nav-brand {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--accent-primary);
}

.nav-links {
  display: none; /* Hidden on mobile by default */
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
}

.nav-link:hover, .nav-link.is-current {
  color: var(--text-primary);
  background: rgba(59, 130, 246, 0.1);
}

.icon-btn {
  background: transparent;
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.icon-btn:hover {
  background: var(--bg-secondary);
  transform: scale(1.05);
}

.icon-sun { display: none; }
.icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: none; }

.mobile-only { display: block; }

/* Mobile Menu Overlay */
.mobile-menu {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 99;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  transform: translateX(100%);
  transition: transform 0.3s ease;
}

.mobile-menu.is-open {
  transform: translateX(0);
}

.mobile-menu .nav-link {
  font-size: 1.5rem;
  font-family: var(--font-heading);
}

/* Layout */
.site-shell {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: calc(var(--nav-height) + var(--space-md)) var(--space-sm) var(--space-lg);
}

.section {
  margin-top: var(--space-lg);
}

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

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 700;
  margin-bottom: var(--space-xs);
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

/* Hero Section */
.hero-section {
  text-align: center;
  padding: var(--space-lg) 0;
}

.hero-badge {
  display: inline-block;
  background: rgba(59, 130, 246, 0.15);
  color: var(--accent-primary);
  padding: 6px 16px;
  border-radius: 99px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 8vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-xs);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--accent-secondary);
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.hero-text {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--space-md);
  font-size: 1.1rem;
}

.highlight {
  color: var(--accent-tertiary);
  font-weight: 700;
}

.hero-actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--space-md);
}

.btn {
  text-decoration: none;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-primary {
  background: var(--accent-primary);
  color: white;
  border: 1px solid var(--accent-primary);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(59, 130, 246, 0.3);
}

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

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

.hero-tags {
  display: flex;
  gap: 8px;
  justify-content: center;
  flex-wrap: wrap;
}

.tag {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  padding: 6px 12px;
  border-radius: 99px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Cards & Glassmorphism */
.glass-card, .card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  box-shadow: var(--card-shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

/* About Grid */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

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

.card h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
}

.stat-card {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  text-align: center;
}

.stat-number {
  display: block;
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent-primary);
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Portfolio Matrix */
.filter-row {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: var(--space-md);
  scrollbar-width: none;
}

.filter-row::-webkit-scrollbar { display: none; }

.filter-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 99px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.filter-btn.is-active, .filter-btn:hover {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
}

.portfolio-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

.portfolio-card {
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.portfolio-card.hidden {
  display: none;
}

.portfolio-card.locked {
  opacity: 0.6;
  filter: grayscale(0.8);
}

.card-image {
  height: 160px;
  width: 100%;
  background-size: cover;
  background-position: center;
}

/* Placeholder gradients for images */
.academics-bg { background: linear-gradient(135deg, #3b82f6, #1d4ed8); }
.science-bg { background: linear-gradient(135deg, #10b981, #047857); }
.karate-bg { background: linear-gradient(135deg, #f59e0b, #b45309); }
.tt-bg { background: linear-gradient(135deg, #ec4899, #be185d); }
.puzzle-bg { background: linear-gradient(135deg, #8b5cf6, #6d28d9); }
.art-bg { background: linear-gradient(135deg, #64748b, #334155); }

.card-content {
  padding: var(--space-sm);
}

.card-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-primary);
  margin-bottom: 8px;
}

.card-content h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.card-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Timeline */
.timeline {
  list-style: none;
  position: relative;
  padding-left: 24px;
  border-left: 2px solid var(--glass-border);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-md);
  padding-left: var(--space-sm);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -31px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-tertiary);
  border: 2px solid var(--bg-primary);
}

.timeline-item .year {
  display: inline-block;
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--accent-primary);
  font-size: 0.9rem;
  margin-bottom: 4px;
}

.timeline-item h3 {
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.timeline-item p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Goals */
.goal-list {
  list-style: none;
  margin-top: var(--space-sm);
}

.goal-list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--glass-border);
  color: var(--text-secondary);
  font-size: 1rem;
}

.goal-list li:last-child {
  border-bottom: none;
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--space-lg) var(--space-sm);
  color: var(--text-secondary);
  border-top: 1px solid var(--glass-border);
  margin-top: var(--space-lg);
}

.footer .small {
  font-size: 0.85rem;
  margin-top: 8px;
  opacity: 0.7;
}

/* Animations */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Desktop Responsive */
@media (min-width: 768px) {
  .mobile-only { display: none; }
  
  .nav-links {
    display: flex;
    gap: 8px;
  }

  .about-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .portfolio-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-section {
    text-align: left;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    align-items: center;
  }

  .hero-actions, .hero-tags {
    justify-content: flex-start;
  }
}

@media (min-width: 1024px) {
  .portfolio-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .site-shell {
    padding-left: var(--space-md);
    padding-right: var(--space-md);
  }
}