:root {
  --primary: #38bdf8;         /* Sky Blue */
  --primary-dark: #0ea5e9;
  --primary-light: #7dd3fc;
  --secondary: #14b8a6;       /* Teal */
  --accent: #f472b6;          /* Keep for visual contrast */
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --bg-primary: #0f172a;      /* Keep for deep dark base */
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --border: #475569;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.2);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.2);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4), 0 4px 6px -4px rgb(0 0 0 / 0.3);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.45), 0 8px 10px -6px rgb(0 0 0 / 0.35);
  --gradient-primary: linear-gradient(135deg, #38bdf8 0%, #7dd3fc 100%);
  --gradient-secondary: linear-gradient(135deg, #14b8a6 0%, #67e8f9 100%);
  --gradient-accent: linear-gradient(135deg, #f472b6 0%, #fb7185 100%);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  scroll-behavior: smooth;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(15, 23, 42, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: all 0.3s ease;
}

.nav-scrolled {
  background: rgba(15, 23, 42, 1);
  box-shadow: var(--shadow-md);
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
}


.logo {
  display: flex;
  align-items: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  gap: 0.5rem;
}

.logo-icon {
  height: 40px;
  width: auto;
  display: block;
}


.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
}

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

.nav-links a:hover::after {
  width: 100%;
}


.particles-canvas-wrapper {
  position: absolute;
  inset: 0;
  z-index: 1;
  overflow: hidden;
}

#particles-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: block;
  z-index: 1;
}




/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(to right, #0e1526, #0a1120);
  color: var(--text-primary);
  position: relative;
  overflow: hidden;
}


.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.hero-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 50px;
  padding: 0.75rem 1.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 2rem;
  color: var(--text-secondary);
  backdrop-filter: blur(6px);
}

.hero-title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.hero-subtitle {
  font-size: clamp(1.125rem, 2.5vw, 1.375rem);
  color: var(--text-secondary);
  opacity: 0.9;
  margin-bottom: 3rem;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  padding: 1rem 2rem;
  border-radius: 0.75rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

/* Sections */
.section {
  padding: 6rem 0;
}

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

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-badge {
  display: inline-block;
  background: var(--primary);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
}

/* About Section */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 3rem;
  margin-top: 4rem;
}

.feature-card {
  background: var(--bg-primary);
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: all 0.3s ease;
  border: 1px solid var(--border);
}

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

.feature-icon {
  width: 3rem;
  height: 3rem;
  border-radius: 0.75rem;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
  color: white;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.feature-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Research Section */
.research-areas {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 3rem;
}

.research-tag {
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.5rem;
  text-align: center;
  transition: all 0.3s ease;
  cursor: pointer;
}

.research-tag:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.research-tag:hover h4 {
  color: white;
}

.research-tag:hover p {
  color: rgba(255, 255, 255, 0.9);
}

.research-tag h4 {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.research-tag p {
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* Publications Section */
.publications-grid {
  display: grid;
  gap: 2rem;
  margin-top: 3rem;
}

.publication-card {
  background: var(--bg-primary);
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
  transition: all 0.3s ease;
  display: flex;
  gap: 1.5rem;
}

.publication-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.publication-icon {
  width: 3rem;
  height: 3rem;
  border-radius: 0.5rem;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
}

.publication-content {
  flex: 1;
}

.publication-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  line-height: 1.4;
}

.publication-title a {
  color: var(--primary);
  text-decoration: none;
}

.publication-title a:hover {
  text-decoration: underline;
}

.publication-meta {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.publication-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.publication-link {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: 2rem;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.3s ease;
}

.publication-link:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-1px);
}

/* Contact Section */
.contact {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.contact .section-title {
  color: var(--text-primary);
}

.contact .section-subtitle {
  color: var(--text-secondary);
}

.contact-cta {
  margin-top: 2rem;
  text-align: center;
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: 0.75rem;
  padding: 1.25rem 2rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.125rem;
  transition: all 0.3s ease;
}

.contact-email:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
  justify-content: center;
}

.contact-box {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 1.5rem;
  text-align: center;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  backdrop-filter: blur(10px);
}

.contact-box:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
  border-color: var(--primary);
}

.contact-box .icon {
  color: var(--primary-light);
}

.contact-box .label {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}


/* Footer */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border);
  padding: 3rem 0;
  text-align: center;
}

.footer-content {
  color: var(--text-primary);
  font-size: 0.95rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--primary);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  opacity: 1;
  transform: translateY(0);
  transition: all 0.8s ease;
}

.fade-in.animate {
  opacity: 0;
  transform: translateY(30px);
}

.fade-in.animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 1rem;
  }

  .nav-inner {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem 0;
  }

  .nav-links {
    gap: 1rem;
  }

  .hero {
    min-height: 80vh;
    text-align: center;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .section {
    padding: 4rem 0;
  }

  .about-grid,
  .research-areas {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .publication-card {
    flex-direction: column;
  }

  .publication-icon {
    margin-bottom: 1rem;
  }
}

.pub-year {
  display: inline-block;
  font-weight: 700;
  color: var(--primary-light);
  margin-right: 0.5rem;
}


.career-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2.5rem;
  margin-top: 4rem;
}

.career-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: all 0.3s ease;
}

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

.career-role {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.career-meta {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.career-description {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.career-link {
  color: var(--primary-light);
  text-decoration: none;
  transition: color 0.3s ease;
}

.career-link:hover {
  color: white;
  text-decoration: underline;
}