/* ============================================
   Modern Portfolio Styles
   Inspired by jpwahle.com
   ============================================ */

/* CSS Variables for theming */
:root {
  /* Colors - Light Mode */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #e9ecef;
  --text-primary: #1a1a2e;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --accent-primary: #6366f1;
  --accent-secondary: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
  --border-color: #e2e8f0;
  --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 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Spacing */
  --container-max: 900px;
  --section-gap: 5rem;
  --card-radius: 16px;
  --btn-radius: 8px;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-tertiary: #252542;
  --text-primary: #f7fafc;
  --text-secondary: #cbd5e0;
  --text-muted: #a0aec0;
  --accent-primary: #818cf8;
  --accent-secondary: #a78bfa;
  --border-color: #2d3748;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
}

/* ============================================
   Base Styles
   ============================================ */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
  color: var(--accent-secondary);
  text-decoration: underline;
}

h1, h2, h3, h4 {
  line-height: 1.3;
  font-weight: 600;
}

::selection {
  background: var(--accent-primary);
  color: white;
}

/* ============================================
   Layout
   ============================================ */

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.section {
  margin-bottom: var(--section-gap);
  animation: fadeInUp 0.6s ease backwards;
}

.section:nth-child(1) { animation-delay: 0.1s; }
.section:nth-child(2) { animation-delay: 0.2s; }
.section:nth-child(3) { animation-delay: 0.3s; }
.section:nth-child(4) { animation-delay: 0.4s; }
.section:nth-child(5) { animation-delay: 0.5s; }
.section:nth-child(6) { animation-delay: 0.6s; }

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================
   Theme Toggle - Animated Sun/Moon
   ============================================ */

.theme-toggle {
  --toggle-orbit-size: 36px;
  --toggle-sun-size: 24px;
  --toggle-moon-size: 20px;
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  width: 56px;
  height: 56px;
  border: none;
  border-radius: 50%;
  background: var(--bg-secondary);
  cursor: pointer;
  box-shadow: var(--card-shadow);
  transition: all var(--transition-normal);
  overflow: hidden;
  padding: 0;
}

.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: var(--card-shadow-hover);
}

.theme-toggle-inner {
  position: relative;
  width: 100%;
  height: 100%;
  display: block;
}

.theme-toggle-inner::before {
  content: '';
  position: absolute;
  inset: 0;
  margin: auto;
  width: var(--toggle-orbit-size);
  height: var(--toggle-orbit-size);
  box-sizing: border-box;
  border: 2px solid rgba(148, 163, 184, 0.35);
  border-radius: 50%;
  pointer-events: none;
  transition: border-color var(--transition-normal);
}

/* Sun icon */
.sun-icon {
  position: absolute;
  inset: 0;
  margin: auto;
  width: var(--toggle-sun-size);
  height: var(--toggle-sun-size);
  color: #f59e0b;
  transition: all 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  transform: rotate(0deg) scale(1);
  transform-origin: center center;
  opacity: 0;
}

/* Sun rays - orbit effect */
.sun-icon::before {
  content: none;
}

/* Sun glow pulse */
.sun-icon::after {
  content: '';
  position: absolute;
  inset: 0;
  margin: auto;
  width: calc(var(--toggle-sun-size) + 6px);
  height: calc(var(--toggle-sun-size) + 6px);
  background: radial-gradient(circle, rgba(245, 158, 11, 0.3) 0%, transparent 70%);
  border-radius: 50%;
  animation: sunPulse 2s ease-in-out infinite;
}

@keyframes sunOrbit {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

@keyframes sunPulse {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(1.1); }
}

/* Moon icon */
.moon-icon {
  position: absolute;
  inset: 0;
  margin: auto;
  width: var(--toggle-moon-size);
  height: var(--toggle-moon-size);
  background: linear-gradient(135deg, #e2e8f0 0%, #94a3b8 100%);
  border-radius: 50%;
  transition: all 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  transform: rotate(0deg) scale(1);
  transform-origin: center center;
  box-shadow: inset -3px -2px 0 #64748b;
}

/* Moon craters */
.moon-icon::before {
  content: '';
  position: absolute;
  width: 5px;
  height: 5px;
  background: rgba(100, 116, 139, 0.3);
  border-radius: 50%;
  top: 4px;
  left: 8px;
}

.moon-icon::after {
  content: '';
  position: absolute;
  width: 3px;
  height: 3px;
  background: rgba(100, 116, 139, 0.3);
  border-radius: 50%;
  bottom: 4px;
  left: 4px;
}

/* Stars around moon (visible in dark mode) */
.moon-stars {
  position: absolute;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.moon-stars span {
  position: absolute;
  width: 2px;
  height: 2px;
  background: #fbbf24;
  border-radius: 50%;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.moon-stars span:nth-child(1) { top: 8px; left: 8px; animation: twinkle 2s ease-in-out infinite; }
.moon-stars span:nth-child(2) { top: 12px; right: 10px; animation: twinkle 2s ease-in-out 0.5s infinite; }
.moon-stars span:nth-child(3) { bottom: 10px; left: 10px; animation: twinkle 2s ease-in-out 1s infinite; }
.moon-stars span:nth-child(4) { bottom: 14px; right: 8px; animation: twinkle 2s ease-in-out 1.5s infinite; }

@keyframes twinkle {
  0%, 100% { opacity: 0.3; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.2); }
}

/* Light mode state */
.sun-icon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

.moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* Dark mode state */
[data-theme="dark"] .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .moon-icon {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

[data-theme="dark"] .moon-stars span {
  opacity: 1;
}

[data-theme="dark"] .theme-toggle {
  background: var(--bg-tertiary);
}

[data-theme="dark"] .theme-toggle-inner::before {
  border-color: rgba(245, 158, 11, 0.45);
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
  padding: 4rem 0 3rem;
}

.hero-content {
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
}

.hero-image {
  position: relative;
  flex-shrink: 0;
}

.avatar {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: var(--card-shadow-hover);
  border: 4px solid var(--bg-secondary);
  transition: all var(--transition-normal);
}

.avatar:hover {
  transform: scale(1.05);
}

.avatar-placeholder {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  font-weight: 700;
  color: white;
  box-shadow: var(--card-shadow);
}

.status-indicator {
  position: absolute;
  bottom: 8px;
  right: 8px;
  width: 20px;
  height: 20px;
  background: #10b981;
  border: 3px solid var(--bg-primary);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.hero-text h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.bio {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  max-width: 600px;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  border-radius: var(--btn-radius);
  font-weight: 500;
  font-size: 0.9rem;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
  color: white;
  text-decoration: none;
}

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

.btn-secondary:hover {
  background: var(--bg-tertiary);
  transform: translateY(-2px);
  text-decoration: none;
  color: var(--text-primary);
}

/* ============================================
   Section Titles
   ============================================ */

.section-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.title-icon {
  font-size: 1.3rem;
}

.section-intro {
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

/* ============================================
   News Section
   ============================================ */

.news-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.news-item {
  display: grid;
  grid-template-columns: 80px 30px 1fr;
  gap: 0.75rem;
  align-items: flex-start;
  padding: 1rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.news-item:hover {
  transform: translateX(4px);
  border-color: var(--accent-primary);
}

.news-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

.news-icon {
  font-size: 1.1rem;
}

.news-item p {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.95rem;
}

.news-item.is-hidden {
  display: none;
}

.news-toggle-btn {
  margin: 0.85rem auto 0;
  display: block;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.86rem;
  font-weight: 500;
  padding: 0.15rem 0.35rem;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color var(--transition-fast), opacity var(--transition-fast);
  opacity: 0.8;
}

.news-toggle-btn:hover {
  color: var(--accent-primary);
  opacity: 1;
}

/* ============================================
   Publications Section
   ============================================ */

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat-card {
  text-align: center;
  padding: 1.5rem 1rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.publications-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.publication-item {
  padding: 1.25rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.publication-item:hover {
  border-color: var(--accent-primary);
  box-shadow: var(--card-shadow);
}

.publication-venue {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.publication-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  background: var(--accent-gradient);
  color: white;
  border-radius: 4px;
  font-weight: 500;
}

.publication-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.publication-title {
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.publication-title a {
  color: inherit;
}

.publication-title a:hover {
  color: var(--accent-primary);
}

.publication-authors {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.publication-authors strong {
  color: var(--accent-primary);
}

.publication-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.publication-citations {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* ============================================
   Projects Section
   ============================================ */

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.project-card {
  padding: 1.5rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
  border-color: var(--accent-primary);
}

.project-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.project-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.project-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  flex-grow: 1;
  margin-bottom: 1rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tag {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: 4px;
  font-family: var(--font-mono);
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 500;
}

/* ============================================
   Timeline Section
   ============================================ */

.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
  padding-bottom: 2rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -2rem;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 3px solid var(--accent-primary);
}

.timeline-marker.current {
  background: var(--accent-primary);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.timeline-marker.edu {
  border-color: #10b981;
}

.timeline-content h3 {
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.timeline-org {
  font-size: 0.95rem;
  color: var(--accent-primary);
  margin-bottom: 0.25rem;
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.timeline-content > p:last-child {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ============================================
   Skills Section
   ============================================ */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.25rem;
}

.skill-category {
  padding: 1.25rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
}

.skill-category h3 {
  font-size: 1rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--accent-primary);
}

.skill-category ul {
  list-style: none;
}

.skill-category li {
  padding: 0.35rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
  position: relative;
  padding-left: 1rem;
}

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

/* ============================================
   Contact Section
   ============================================ */

.contact-content {
  text-align: center;
}

.contact-content > p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr));
  gap: 1rem;
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  padding: 1.5rem;
  background: var(--bg-secondary);
  border-radius: var(--card-radius);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.contact-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-primary);
  text-decoration: none;
  color: var(--accent-primary);
}

.contact-card i {
  font-size: 1.5rem;
  color: var(--accent-primary);
}

.contact-card span {
  font-size: 0.9rem;
}

/* ============================================
   Footer
   ============================================ */

.footer {
  text-align: center;
  padding: 3rem 1.5rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.9rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-secret-hint {
  margin-top: 0.35rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  opacity: 0.8;
}

/* ============================================
   Easter Egg Elements
   ============================================ */

#space-interest {
  cursor: pointer;
  transition: all 0.2s ease;
  user-select: none;
}

#space-interest:hover {
  color: var(--accent-primary);
}

.easter-indicator {
  display: inline-block;
  margin-left: 0.25rem;
  color: #fbbf24;
  font-size: 0.8em;
  animation: easterTwinkle 1.8s ease-in-out infinite;
}

@keyframes easterTwinkle {
  0%, 100% { opacity: 0.45; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.12); }
}

.easter-egg-modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  animation: fadeIn 0.3s ease;
}

.easter-egg-modal.active {
  display: flex;
}

.modal-content {
  background: var(--bg-secondary);
  padding: 3rem;
  border-radius: var(--card-radius);
  text-align: center;
  max-width: 400px;
  animation: scaleIn 0.3s ease;
}

.modal-content h2 {
  margin-bottom: 1rem;
}

.modal-content p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.modal-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.modal-buttons .btn {
  min-width: 170px;
}

.modal-buttons .btn-secondary {
  text-decoration: none;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes scaleIn {
  from { transform: scale(0.9); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
  .container {
    padding: 1.5rem 1rem;
  }
  
  .hero-content {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .hero-text h1 {
    font-size: 2rem;
  }
  
  .hero-links {
    justify-content: center;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .news-item {
    grid-template-columns: 60px 24px 1fr;
  }
  
  .theme-toggle {
    top: 1rem;
    right: 1rem;
    width: 40px;
    height: 40px;
    --toggle-orbit-size: 26px;
    --toggle-sun-size: 18px;
    --toggle-moon-size: 16px;
  }
  
  .modal-content {
    margin: 1rem;
    padding: 2rem;
  }
  
  .modal-buttons {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .section-title {
    font-size: 1.25rem;
  }
  
  .stats-grid {
    gap: 0.75rem;
  }
  
  .stat-card {
    padding: 1rem;
  }
  
  .stat-number {
    font-size: 1.5rem;
  }
  
  .projects-grid {
    grid-template-columns: 1fr;
  }
  
  .skills-grid {
    grid-template-columns: 1fr;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   Print Styles
   ============================================ */

@media print {
  .theme-toggle,
  .easter-egg-hint,
  .gamification-bar,
  .achievement-toast,
  .footer-hint {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  a {
    color: inherit;
  }
}