/* ======================
   CSS Reset & Base Styles
   ====================== */

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

:root {
  /* Colors - Light Mode */
  --primary-color: #2563eb;
  --secondary-color: #7c3aed;
  --accent-color: #06b6d4;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);

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

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ======================
   Navigation Bar
   ====================== */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.logo:hover {
  color: var(--secondary-color);
}

.nav-menu {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
}

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

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--text-secondary);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  color: var(--primary-color);
  background-color: var(--bg-secondary);
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 0.375rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
}

.mobile-menu-toggle span {
  display: block;
  width: 1.5rem;
  height: 0.125rem;
  background-color: var(--text-primary);
  transition: all var(--transition-base);
}

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

.hero {
  padding: 120px 0 80px;
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.hero-content {
  animation: fadeInUp 0.8s ease-out;
}

.greeting {
  display: block;
  color: var(--text-secondary);
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.name {
  display: block;
  font-size: 3.5rem;
  font-weight: 800;
  background: linear-gradient(
    135deg,
    var(--primary-color),
    var(--secondary-color)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-md);
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  font-weight: 500;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
}

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

.social-links a {
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
}

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

.hero-image {
  animation: fadeIn 1s ease-out 0.3s both;
}

.profile-image-container {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.profile-image {
  width: 100%;
  height: auto;
  display: block;
}

.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.scroll-indicator a {
  color: var(--text-secondary);
  font-size: 1.5rem;
  text-decoration: none;
}

/* ======================
   Sections
   ====================== */

.section {
  padding: var(--spacing-3xl) 0;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: var(--spacing-2xl);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-fast);
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

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

.btn-primary:hover {
  background-color: #1d4ed8;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
  background-color: var(--primary-color);
  color: white;
}

.btn-link {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: all var(--transition-fast);
}

.btn-link:hover {
  color: var(--secondary-color);
  gap: var(--spacing-md);
}

/* ======================
   About Section
   ====================== */

.about-section {
  background-color: var(--bg-secondary);
}

.about-content {
  display: grid;
  gap: var(--spacing-2xl);
}

.about-text {
  max-width: 800px;
  margin: 0 auto;
}

.about-text .lead {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
}

.about-text p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
  line-height: 1.8;
}

.skills-section h3 {
  font-size: 1.75rem;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.skill-category {
  background-color: var(--bg-primary);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.skill-category h4 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.tag {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
}

.knowledge-section h3 {
  font-size: 1.75rem;
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.knowledge-category {
  background-color: var(--bg-primary);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.knowledge-category h4 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  color: var(--primary-color);
}

.knowledge-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.icon-pi {
  display: inline-block;
  width: 1.25em;
  text-align: center;
  font-style: italic;
  font-weight: 600;
  font-size: 1.1em;
  color: var(--primary-color);
  margin-right: 0.2rem;
}

/* ======================
   Research Section
   ====================== */

.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.research-card {
  background-color: var(--bg-primary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow);
  transition: all var(--transition-base);
  border: 1px solid var(--border-color);
}

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

.research-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: var(--spacing-md);
}

.research-header h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
}

.research-status {
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.research-status.current {
  background-color: #dbeafe;
  color: #1e40af;
}

.research-status.completed {
  background-color: #d1fae5;
  color: #065f46;
}

.research-description {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.research-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.research-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

/* ======================
   Blog Section
   ====================== */

.blog-filters {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.filter-btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 500;
  transition: all var(--transition-fast);
}

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

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.blog-card {
  background-color: var(--bg-primary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all var(--transition-base);
  border: 1px solid var(--border-color);
}

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

.blog-image {
  width: 100%;
  height: 200px;
  overflow: hidden;
  background-color: var(--bg-secondary);
}

.blog-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.blog-card:hover .blog-image img {
  transform: scale(1.05);
}

.blog-content {
  padding: var(--spacing-lg);
}

.blog-meta {
  display: flex;
  gap: var(--spacing-md);
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
}

.blog-meta i {
  margin-right: var(--spacing-xs);
}

.blog-content h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.blog-content p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.blog-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

/* ======================
   Gallery Section
   ====================== */

.gallery-section {
  background-color: var(--bg-secondary);
}

.gallery-tabs {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
  flex-wrap: wrap;
}

.gallery-tab {
  padding: 0.5rem 1.5rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.gallery-tab:hover,
.gallery-tab.active {
  background-color: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.gallery-item {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 4/3;
  background-color: var(--bg-tertiary);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.gallery-item:hover img {
  transform: scale(1.1);
}

.gallery-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--spacing-lg);
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
  color: white;
  transform: translateY(100%);
  transition: transform var(--transition-base);
}

.gallery-item:hover .gallery-overlay {
  transform: translateY(0);
}

.gallery-overlay h4 {
  margin-bottom: var(--spacing-xs);
}

.gallery-overlay p {
  font-size: 0.875rem;
  opacity: 0.9;
}

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

.contact-content {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--spacing-3xl);
  max-width: 1000px;
  margin: 0 auto;
}

.contact-info h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-lg);
}

.contact-item {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.contact-item i {
  font-size: 1.5rem;
  color: var(--primary-color);
  width: 2rem;
}

.contact-item h4 {
  font-size: 0.875rem;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.contact-item a {
  color: var(--primary-color);
  text-decoration: none;
}

.contact-item a:hover {
  text-decoration: underline;
}

.contact-form {
  background-color: var(--bg-secondary);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  color: var(--text-primary);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: all var(--transition-fast);
  background-color: var(--bg-primary);
  color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

.footer {
  background-color: var(--bg-tertiary);
  padding: var(--spacing-3xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-3xl);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h3,
.footer-section h4 {
  margin-bottom: var(--spacing-md);
}

.footer-section p {
  color: var(--text-secondary);
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section ul li a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-section ul li a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.footer-bottom p {
  margin-bottom: var(--spacing-sm);
}

/* ======================
   Animations
   ====================== */

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

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

@keyframes bounce {
  0%,
  100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(-10px);
  }
}

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

@media (max-width: 968px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-image {
    order: -1;
    max-width: 400px;
    margin: 0 auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .social-links {
    justify-content: center;
  }

  .contact-content {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .name {
    font-size: 2.5rem;
  }

  .research-grid,
  .blog-grid,
  .gallery-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 480px) {
  .name {
    font-size: 2rem;
  }

  .hero-cta {
    flex-direction: column;
    width: 100%;
  }

  .hero-cta .btn {
    width: 100%;
    justify-content: center;
  }
}