@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

/* Color Variables - Dark Theme (Default) */
:root {
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Theme colors - Dark */
  --bg-color: hsl(222, 47%, 10%);
  --bg-gradient: radial-gradient(circle at 10% 20%, hsl(222, 47%, 12%) 0%, hsl(222, 47%, 8%) 90%);
  --surface-color: hsl(222, 40%, 15%);
  --surface-hover: hsl(222, 35%, 18%);
  --border-color: hsl(222, 30%, 22%);
  --border-focus: hsl(195, 100%, 40%);
  
  --text-primary: hsl(210, 40%, 98%);
  --text-secondary: hsl(215, 20%, 75%);
  --text-muted: hsl(215, 15%, 55%);
  
  --primary: hsl(195, 100%, 50%);
  --primary-hover: hsl(195, 100%, 40%);
  --primary-light: hsla(195, 100%, 50%, 0.1);
  --secondary: hsl(270, 95%, 68%);
  --secondary-light: hsla(270, 95%, 68%, 0.1);
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.3);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --sidebar-width: 320px;
}

/* Light Theme overrides */
@media (prefers-color-scheme: light) {
  :root {
    --bg-color: hsl(210, 40%, 98%);
    --bg-gradient: linear-gradient(135deg, hsl(210, 40%, 98%) 0%, hsl(214, 32%, 95%) 100%);
    --surface-color: hsl(0, 0%, 100%);
    --surface-hover: hsl(210, 30%, 99%);
    --border-color: hsl(214, 32%, 90%);
    --border-focus: hsl(210, 100%, 50%);
    
    --text-primary: hsl(222, 47%, 12%);
    --text-secondary: hsl(215, 25%, 35%);
    --text-muted: hsl(215, 16%, 50%);
    
    --primary: hsl(210, 100%, 50%);
    --primary-hover: hsl(210, 100%, 40%);
    --primary-light: hsla(210, 100%, 50%, 0.08);
    --secondary: hsl(262, 80%, 55%);
    --secondary-light: hsla(262, 80%, 55%, 0.08);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 40px rgba(220, 225, 235, 0.6);
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 2rem;
}

body {
  font-family: var(--font-body);
  background: var(--bg-color);
  background-image: var(--bg-gradient);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-color);
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.25;
}

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

a:hover {
  color: var(--primary-hover);
  text-decoration: none;
}

/* Layout Structure */
.app-container {
  display: flex;
  min-height: 100vh;
  position: relative;
  max-width: 1440px;
  margin: 0 auto;
}

/* Sidebar Styling */
.sidebar {
  width: var(--sidebar-width);
  position: fixed;
  top: 0;
  bottom: 0;
  left: max(0px, calc((100vw - 1440px) / 2));
  background: var(--surface-color);
  border-right: 1px solid var(--border-color);
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  z-index: 100;
  overflow-y: auto;
}

.sidebar-profile {
  text-align: center;
  margin-bottom: 2rem;
}

.profile-avatar-container {
  position: relative;
  width: 140px;
  height: 140px;
  margin: 0 auto 1.5rem;
}

.profile-avatar {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.profile-avatar-container:hover .profile-avatar {
  border-color: var(--primary);
  transform: scale(1.03);
}

.profile-name {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 0.25rem;
  letter-spacing: -0.5px;
}

.profile-title {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 1rem;
}

/* Nav Menu */
.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  border-radius: 8px;
  border: 1px solid transparent;
  transition: var(--transition);
}

.nav-link svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
  opacity: 0.8;
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
  background: var(--primary-light);
  border-color: hsla(195, 100%, 50%, 0.15);
}

.nav-link:hover svg, .nav-link.active svg {
  transform: translateX(2px);
  opacity: 1;
}

/* Sidebar Contact & Socials */
.sidebar-footer {
  margin-top: auto;
}

.contact-info {
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.contact-item svg {
  width: 16px;
  height: 16px;
  fill: var(--text-muted);
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
}

.social-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--surface-hover);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  transition: var(--transition);
}

.social-btn svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.social-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-light);
  transform: translateY(-3px);
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 3.5rem;
  max-width: calc(1440px - var(--sidebar-width));
}

/* Section Styling */
.section {
  margin-bottom: 4rem;
}

.section-title {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  letter-spacing: -0.5px;
  position: relative;
}

.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-color);
}

.section-title svg {
  width: 24px;
  height: 24px;
  fill: var(--primary);
}

/* About Section Specifics */
.about-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.about-text {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  text-align: justify;
}

.about-text p {
  margin-bottom: 1.25rem;
}

.about-text p:last-child {
  margin-bottom: 0;
}

/* Experience Timeline / Cards */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.timeline-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 1.5rem;
}

.timeline-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

.timeline-meta {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.timeline-dates {
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.timeline-location {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
}

.timeline-location svg {
  width: 14px;
  height: 14px;
  fill: var(--text-muted);
}

.timeline-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.timeline-org {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

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

.timeline-desc p {
  margin-bottom: 0.75rem;
}
.timeline-desc p:last-child {
  margin-bottom: 0;
}

/* Research Projects */
.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.project-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  transition: var(--transition);
}

.project-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

.project-img-container {
  position: relative;
  background: hsl(222, 47%, 6%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  border-right: 1px solid var(--border-color);
}

.project-img {
  width: 100%;
  height: 100%;
  max-height: 240px;
  object-fit: contain;
  border-radius: 8px;
}

.project-body {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.project-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.project-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.project-links {
  display: flex;
  gap: 1rem;
  margin-top: auto;
}

/* Buttons / Badges */
.btn-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border-color);
  background: var(--surface-hover);
  color: var(--text-secondary);
  transition: var(--transition);
}

.btn-pill svg {
  width: 14px;
  height: 14px;
  fill: currentColor;
}

.btn-pill:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-light);
}

/* Publications List */
.publications-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pub-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  transition: var(--transition);
}

.pub-card:hover {
  transform: translateX(4px);
  border-color: var(--border-focus);
}

.pub-icon-wrapper {
  background: var(--primary-light);
  color: var(--primary);
  padding: 0.65rem;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.pub-icon-wrapper svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.pub-content {
  flex: 1;
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.pub-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
  line-height: 1.4;
}

.pub-venue {
  font-size: 0.85rem;
  font-style: italic;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.pub-links {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.pub-link {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.pub-link svg {
  width: 12px;
  height: 12px;
  fill: currentColor;
}

/* Awards List */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.award-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  transition: var(--transition);
}

.award-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-focus);
}

.award-icon-wrapper {
  background: var(--secondary-light);
  color: var(--secondary);
  padding: 0.65rem;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.award-icon-wrapper svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.award-content {
  flex: 1;
}

.award-dates {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--secondary);
  margin-bottom: 0.25rem;
}

.award-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.award-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Responsive Styles */
@media (max-width: 991.98px) {
  .sidebar {
    width: 100%;
    position: relative;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding: 2rem;
    left: auto;
  }
  
  .sidebar-profile {
    display: flex;
    text-align: left;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
  }
  
  .profile-avatar-container {
    width: 100px;
    height: 100px;
    margin: 0;
  }
  
  .profile-name {
    font-size: 1.4rem;
  }
  
  .nav-menu {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 1.5rem;
    gap: 0.35rem;
  }
  
  .nav-link {
    padding: 0.5rem 0.75rem;
    font-size: 0.85rem;
  }
  
  .contact-info {
    border-top: none;
    padding-top: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 1.5rem;
  }
  
  .contact-item {
    margin-bottom: 0;
  }
  
  .app-container {
    flex-direction: column;
  }
  
  .main-content {
    margin-left: 0;
    padding: 2rem;
    max-width: 100%;
  }
  
  .timeline-card {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  
  .project-card {
    grid-template-columns: 1fr;
  }
  
  .project-img-container {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding: 1rem;
  }
}

@media (max-width: 575.98px) {
  .sidebar-profile {
    flex-direction: column;
    text-align: center;
  }
  
  .profile-avatar-container {
    margin: 0 auto;
  }
  
  .contact-info {
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
  }
  
  .main-content {
    padding: 1.25rem;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .about-card, .project-body, .timeline-card, .pub-card, .award-card {
    padding: 1.25rem;
  }
}

/* Footer Styling */
.footer {
  margin-top: 5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer a {
  color: var(--primary);
  font-weight: 600;
  transition: var(--transition);
}

.footer a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}