/* ============================================
   ACADEMIC WEBSITE - STYLESHEET
   Clean, Minimal, Elegant Design
   ============================================ */

/* ---------- CSS Variables / Theming ---------- */
:root {
  /* Colors - Light Mode */
  --color-bg: #fafafa;
  --color-bg-alt: #ffffff;
  --color-text: #2d2d2d;
  --color-text-muted: #6b6b6b;
  --color-accent: #4a6fa5;
  --color-accent-hover: #3d5d8a;
  --color-border: #e5e5e5;
  --color-card-bg: #ffffff;
  --color-code-bg: #f4f4f4;
  --color-nav-bg: rgba(250, 250, 250, 0.85);

  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-heading: 'Playfair Display', Georgia, serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2.5rem;
  --spacing-xl: 3rem;

  /* Sizing */
  --max-width: 1100px;
  --nav-height: 70px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-medium: 0.3s ease;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.1);
}

/* Dark Mode */
[data-theme="dark"] {
  --color-bg: #1a1a1a;
  --color-bg-alt: #242424;
  --color-text: #e8e8e8;
  --color-text-muted: #a0a0a0;
  --color-accent: #7da0ca;
  --color-accent-hover: #9ab8da;
  --color-border: #333333;
  --color-card-bg: #242424;
  --color-code-bg: #2d2d2d;
  --color-nav-bg: rgba(26, 26, 26, 0.85);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
}

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

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

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

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; margin-bottom: var(--spacing-sm); }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }

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

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

a:hover {
  color: var(--color-accent-hover);
}

/* ---------- Utility Classes ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

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

.section-title {
  position: relative;
  display: inline-block;
  margin-bottom: var(--spacing-md);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 40px;
  height: 3px;
  background-color: var(--color-accent);
  border-radius: 2px;
}

.text-muted {
  color: var(--color-text-muted);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Fade-in animation */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background-color: var(--color-nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: background-color var(--transition-medium), border-color var(--transition-medium);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

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

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--spacing-xs) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-text);
}

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

/* Dark Mode Toggle */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  color: var(--color-text-muted);
  font-size: 1.2rem;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  color: var(--color-text);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  transition: opacity var(--transition-fast);
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

[data-theme="light"] .theme-toggle .icon-sun,
:root:not([data-theme]) .theme-toggle .icon-sun {
  display: none;
}

[data-theme="light"] .theme-toggle .icon-moon,
:root:not([data-theme]) .theme-toggle .icon-moon {
  display: block;
}

/* Mobile Menu */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- Hero / About Section ---------- */
.hero {
  padding-top: calc(var(--nav-height) + var(--spacing-lg));
  padding-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--spacing-lg);
  align-items: center;
}

.hero-text h1 {
  margin-bottom: var(--spacing-sm);
}

.hero-tagline {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
}

.hero-bio {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: var(--spacing-md);
}

.hero-image {
  position: relative;
}

.hero-image img {
  width: 100%;
  max-width: 280px;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-medium), box-shadow var(--transition-medium);
}

.hero-image img:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

/* Social Links */
.social-links {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background-color: var(--color-bg-alt);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.social-link:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  transform: translateY(-2px);
}

.social-link svg {
  width: 20px;
  height: 20px;
}

/* ---------- News Section ---------- */
.news {
  background-color: var(--color-bg-alt);
}

.news-list {
  list-style: none;
}

.news-item {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
}

.news-item:last-child {
  border-bottom: none;
}

.news-date {
  flex-shrink: 0;
  width: 100px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent);
}

.news-content {
  flex: 1;
}

.news-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: var(--spacing-md);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-accent);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  transition: color var(--transition-fast);
}

.news-toggle:hover {
  color: var(--color-accent-hover);
}

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

/* ---------- Publications Section ---------- */
.publications-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.pub-card {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: box-shadow var(--transition-medium), transform var(--transition-medium);
}

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

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

.pub-content {
  flex: 1;
  min-width: 0;
}

.pub-image {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

.pub-image img {
  height: 160px;
  width: auto;
  border-radius: 6px;
  object-fit: contain;
}

.pub-title {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  line-height: 1.4;
}

.pub-title a {
  color: var(--color-text);
}

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

.pub-authors {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xs);
}

.pub-authors .me {
  font-weight: 600;
  color: var(--color-text);
}

.pub-venue {
  font-size: 0.9rem;
  font-style: italic;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-accent);
  background-color: transparent;
  border: 1px solid var(--color-accent);
  border-radius: 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pub-link:hover {
  background-color: var(--color-accent);
  color: white;
}

/* Publication Filters */
.pub-filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.pub-filter {
  padding: 6px 16px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-muted);
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pub-filter:hover,
.pub-filter.active {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.pub-filter.active {
  background-color: var(--color-accent);
  color: white;
}

/* ---------- Blog Section ---------- */
.blog {
  background-color: var(--color-bg-alt);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-md);
}

.blog-card {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--spacing-md);
  transition: box-shadow var(--transition-medium), transform var(--transition-medium);
}

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

.blog-card-date {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xs);
}

.blog-card-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  margin-bottom: var(--spacing-xs);
}

.blog-card-title a {
  color: var(--color-text);
}

.blog-card-title a:hover {
  color: var(--color-accent);
}

.blog-card-excerpt {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
  line-height: 1.6;
}

.blog-card-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.9rem;
  font-weight: 500;
}

.blog-card-link:hover {
  gap: 8px;
}

/* ---------- Contact Section ---------- */
.contact-content {
  max-width: 600px;
}

.contact-content p {
  font-size: 1.1rem;
  margin-bottom: var(--spacing-md);
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--color-accent);
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: all var(--transition-fast);
}

.contact-email:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-sm);
}

/* ---------- Footer ---------- */
.footer {
  padding: var(--spacing-md) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

.footer-social {
  display: flex;
  gap: var(--spacing-sm);
}

.footer-social .social-link {
  width: 36px;
  height: 36px;
}

.footer-social .social-link svg {
  width: 16px;
  height: 16px;
}

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

.footer-tagline {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ---------- Modal ---------- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-medium), visibility var(--transition-medium);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  background-color: var(--color-card-bg);
  border-radius: 12px;
  padding: var(--spacing-md);
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  transform: scale(0.9);
  transition: transform var(--transition-medium);
}

.modal-overlay.active .modal {
  transform: scale(1);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-sm);
}

.modal-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 0;
  line-height: 1;
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--color-text);
}

.modal-content pre {
  background-color: var(--color-code-bg);
  padding: var(--spacing-sm);
  border-radius: 8px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-sm);
}

.btn {
  padding: 8px 20px;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-accent);
  color: white;
  border: none;
}

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

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

.btn-secondary:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

/* ---------- Blog Post Page ---------- */
.blog-post {
  padding-top: calc(var(--nav-height) + var(--spacing-md));
  padding-bottom: var(--spacing-lg);
}

.blog-post-header {
  max-width: 750px;
  margin: 0 auto var(--spacing-lg);
  text-align: center;
}

.blog-post-date {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

.blog-post-title {
  font-size: 2.5rem;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

.blog-post-meta {
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

.blog-post-content {
  max-width: 750px;
  margin: 0 auto;
}

.blog-post-content h2 {
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.blog-post-content h3 {
  margin-top: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.blog-post-content p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: var(--spacing-md);
}

.blog-post-content ul,
.blog-post-content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-md);
}

.blog-post-content li {
  margin-bottom: var(--spacing-xs);
  line-height: 1.7;
}

.blog-post-content blockquote {
  margin: var(--spacing-md) 0;
  padding: var(--spacing-sm) var(--spacing-md);
  border-left: 4px solid var(--color-accent);
  background-color: var(--color-bg-alt);
  font-style: italic;
  color: var(--color-text-muted);
}

.blog-post-content blockquote p:last-child {
  margin-bottom: 0;
}

.blog-post-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 2px 6px;
  background-color: var(--color-code-bg);
  border-radius: 4px;
}

.blog-post-content pre {
  margin: var(--spacing-md) 0;
  padding: var(--spacing-md);
  background-color: var(--color-code-bg);
  border-radius: 8px;
  overflow-x: auto;
}

.blog-post-content pre code {
  padding: 0;
  background: none;
  font-size: 0.9rem;
  line-height: 1.6;
}

.blog-post-content img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: var(--spacing-md) 0;
}

.blog-post-content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.blog-post-nav {
  max-width: 750px;
  margin: var(--spacing-lg) auto 0;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-border);
}

.blog-post-nav a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-weight: 500;
}

/* ---------- Responsive Design ---------- */
@media (max-width: 768px) {
  :root {
    --spacing-lg: 2rem;
    --spacing-xl: 2.5rem;
  }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.6rem; }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    flex-direction: column;
    justify-content: center;
    background-color: var(--color-bg);
    border-left: 1px solid var(--color-border);
    padding: var(--spacing-md);
    transform: translateX(100%);
    transition: transform var(--transition-medium);
  }

  .nav-links.active {
    transform: translateX(0);
  }

  .nav-link {
    font-size: 1.1rem;
    padding: var(--spacing-sm) 0;
  }

  .nav-toggle {
    display: flex;
  }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-image {
    order: -1;
    display: flex;
    justify-content: center;
  }

  .hero-image img {
    max-width: 200px;
  }

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

  .news-item {
    flex-direction: column;
    gap: var(--spacing-xs);
  }

  .news-date {
    width: auto;
  }

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

  .blog-post-title {
    font-size: 1.8rem;
  }

  .pub-filters {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }

  .pub-card {
    flex-direction: column-reverse;
    padding: var(--spacing-sm);
  }

  .pub-image {
    width: 100%;
    margin-bottom: var(--spacing-xs);
    justify-content: center;
  }

  .pub-image img {
    height: 120px;
    width: auto;
    max-width: 100%;
  }

  .pub-links {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .pub-link {
    text-align: center;
    justify-content: center;
  }
}

/* Print styles */
@media print {
  .nav,
  .theme-toggle,
  .social-links,
  .pub-links,
  .news-toggle,
  .footer-social {
    display: none;
  }

  body {
    background: white;
    color: black;
  }

  .hero {
    min-height: auto;
    padding-top: var(--spacing-md);
  }
}