/* Modern Academic Homepage Stylesheet */
:root {
  --bg-color: #fcfcfd;
  --card-bg: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-light: #e0f2fe;
  --border-color: #e2e8f0;
  --border-subtle: #f1f5f9;
  --badge-bg: #f8fafc;
  --accent: #0ea5e9;
  --code-bg: #f1f5f9;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
}

body.dark-mode {
  --bg-color: #0b0f19;
  --card-bg: #131b2e;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  --primary: #38bdf8;
  --primary-hover: #7dd3fc;
  --primary-light: #082f49;
  --border-color: #1e293b;
  --border-subtle: #172033;
  --badge-bg: #172033;
  --accent: #38bdf8;
  --code-bg: #0f172a;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.65;
  font-size: 15.5px;
  transition: background-color 0.25s ease, color 0.25s ease;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* Typography */
a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease, text-decoration 0.2s ease;
}

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

h1, h2, h3, h4 {
  color: var(--text-main);
  font-weight: 600;
  letter-spacing: -0.02em;
}

/* Floating Dark Mode Toggle */
.dark-mode-toggle {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  transition: all 0.2s ease;
  font-size: 1.1rem;
}

.dark-mode-toggle:hover {
  transform: scale(1.08);
  border-color: var(--primary);
}

/* Hero / Header Section */
.hero-section {
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.hero-content {
  display: flex;
  flex-direction: column-reverse;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .hero-content {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.hero-text {
  flex: 1;
}

.hero-name {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.4rem;
  line-height: 1.15;
}

.hero-title {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1rem;
}

.hero-title strong {
  color: var(--text-main);
}

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

.phd-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(2, 132, 199, 0.2);
  padding: 0.4rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  margin-bottom: 1.25rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-avatar {
  flex-shrink: 0;
  display: flex;
  justify-content: center;
}

.pfp {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  box-shadow: var(--shadow-md);
  transition: transform 0.25s ease;
}

.pfp:hover {
  transform: scale(1.03);
}

/* Academic & Social Links */
.academic-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: 6px;
  background: var(--card-bg);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: all 0.18s ease;
  text-decoration: none;
}

.link-btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: var(--shadow-md);
}

.link-btn i {
  font-size: 0.95rem;
}

.btn-svg-icon {
  display: inline-block;
  vertical-align: middle;
  flex-shrink: 0;
}

.arxiv-mini-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  font-weight: 700;
  color: #b31b1b;
  background: rgba(179, 27, 27, 0.1);
  padding: 0.1rem 0.35rem;
  border-radius: 3px;
}

/* Main Navigation Bar */
.main-nav {
  position: sticky;
  top: 0;
  background: var(--bg-color);
  backdrop-filter: blur(8px);
  z-index: 100;
  padding: 0.75rem 0;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.main-nav ul {
  display: flex;
  gap: 1.25rem;
  list-style: none;
  overflow-x: auto;
  padding: 0.2rem 0;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--text-main);
  text-decoration: none;
  border-bottom-color: var(--primary);
}

/* Section Styling */
.section {
  margin-bottom: 3rem;
  scroll-margin-top: 5rem;
}

.section-title {
  font-size: 1.4rem;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text-main);
  border-bottom: 2px solid var(--border-subtle);
  padding-bottom: 0.4rem;
}

.section-title i {
  font-size: 1.1rem;
  color: var(--primary);
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.4rem;
  box-shadow: var(--shadow-sm);
}

.card p {
  margin-bottom: 0.85rem;
  color: var(--text-main);
}

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

/* Research Interests Grid */
.interests-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .interests-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.interest-tag {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  transition: all 0.2s ease;
}

.interest-tag:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.interest-tag i {
  font-size: 1.25rem;
  color: var(--primary);
  margin-bottom: 0.2rem;
}

.interest-tag strong {
  font-size: 0.95rem;
  color: var(--text-main);
}

.interest-tag span {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* News List */
.news-card {
  padding: 1rem 1.4rem;
}

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

.news-list li {
  display: flex;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border-subtle);
  align-items: flex-start;
}

.news-list li:last-child {
  border-bottom: none;
  padding-bottom: 0.2rem;
}

.news-date {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 500;
  background: var(--badge-bg);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  white-space: nowrap;
}

.news-text {
  font-size: 0.92rem;
  color: var(--text-main);
  line-height: 1.5;
}

/* Publications */
.pub-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary);
  border-radius: 8px;
  padding: 1.4rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease;
}

.pub-card:hover {
  box-shadow: var(--shadow-md);
}

.pub-title {
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.35;
  margin-bottom: 0.4rem;
}

.pub-authors {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.pub-venue {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.venue-badge {
  font-weight: 600;
  color: var(--primary);
}

.pub-abstract {
  font-size: 0.88rem;
  color: var(--text-main);
  line-height: 1.55;
  margin-bottom: 1rem;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pub-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: 4px;
  background: var(--badge-bg);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  cursor: pointer;
  font-family: inherit;
  transition: all 0.18s ease;
  text-decoration: none;
}

.pub-btn:hover {
  text-decoration: none;
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

.bibtex-block {
  margin-top: 1rem;
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  overflow-x: auto;
}

.bibtex-block pre {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--text-main);
  margin: 0;
  white-space: pre-wrap;
}

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .projects-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s ease;
}

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

.project-card.featured {
  border-color: rgba(2, 132, 199, 0.4);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.project-tag {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
}

.project-actions a {
  font-size: 1.1rem;
  color: var(--text-muted);
}

.project-actions a:hover {
  color: var(--primary);
}

.project-card h3 {
  font-size: 1.05rem;
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.project-card p {
  font-size: 0.86rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.85rem;
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.tech-tags span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  background: var(--badge-bg);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
}

/* Timeline (Education & Experience) */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
  padding-left: 1.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
}

.timeline-dot {
  position: absolute;
  left: -1.5rem;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 3px solid var(--primary);
}

.timeline-content {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.1rem 1.25rem;
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
}

.timeline-header h3 {
  font-size: 1.05rem;
}

.timeline-date {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.timeline-degree {
  font-size: 0.92rem;
  color: var(--text-main);
  margin-bottom: 0.35rem;
}

.timeline-role {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--primary);
  margin-bottom: 0.4rem;
}

.timeline-details {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.timeline-content ul {
  padding-left: 1.2rem;
  margin-top: 0.4rem;
}

.timeline-content li {
  font-size: 0.85rem;
  color: var(--text-main);
  margin-bottom: 0.25rem;
  line-height: 1.45;
}

/* Skills Grid */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .skills-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.skill-category {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.1rem;
}

.skill-category h4 {
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.skill-category p {
  font-size: 0.84rem;
  color: var(--text-muted);
  line-height: 1.5;
}

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

.footer-sub {
  font-size: 0.78rem;
  color: var(--text-light);
  margin-top: 0.25rem;
}