/* Academic Personal Website - Haoli Bai */

:root {
  --color-bg: #f7f9fc;
  --color-text: #080b10;
  --color-text-secondary: #1a2130;
  --color-accent: #2563a8;
  --color-accent-light: #60a5c8;
  --color-border: #d8e3ed;
  --color-card-bg: #ffffff;
  --color-tag: #e8f1f8;
  --font-serif: 'Playfair Display', Georgia, serif;
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --max-width: 960px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: 19px;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: 
    radial-gradient(circle at 15% 25%, rgba(37, 99, 168, 0.04) 0%, transparent 45%),
    radial-gradient(circle at 85% 75%, rgba(96, 165, 200, 0.03) 0%, transparent 45%);
  pointer-events: none;
  z-index: -1;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

/* Header */
header {
  padding: 4rem 0 3rem;
  animation: fadeInUp 0.8s ease-out;
}

.header-content {
  display: flex;
  gap: 3rem;
  align-items: flex-start;
}

.profile-image {
  width: 400px;
  height: auto;
  border-radius: 8px;
  margin-top: 25px;
  object-fit: contain;
  flex-shrink: 0;
  box-shadow: 
    0 4px 6px rgba(0, 0, 0, 0.07),
    0 10px 20px rgba(0, 0, 0, 0.06),
    0 20px 40px rgba(37, 99, 168, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.profile-image:hover {
  transform: translateY(-6px);
  box-shadow: 
    0 8px 16px rgba(0, 0, 0, 0.1),
    0 18px 35px rgba(0, 0, 0, 0.08),
    0 30px 55px rgba(37, 99, 168, 0.15);
}

.header-info h1 {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0rem;
}

.affiliation {
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

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

.contact-email {
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin-bottom: 1.25rem;
}

/* Social Links */
.social-links {
  display: flex;
  gap: 0.75rem;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 6px;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  transition: all 0.2s;
}

.social-links a:hover {
  border-color: var(--color-accent-light);
  box-shadow: 0 4px 12px rgba(37, 99, 168, 0.2);
  transform: translateY(-2px);
}

.social-links img { width: 22px; height: 22px; }

/* Navigation */
nav {
  position: sticky;
  top: 0;
  background: rgba(247, 249, 252, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  margin-bottom: 2rem;
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 0;
}

nav a {
  display: block;
  padding: 0.5rem 1.1rem;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

nav a:hover, nav a.active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* Sections */
section {
  margin-bottom: 3.5rem;
  animation: fadeInUp 0.6s ease-out backwards;
}

h2 {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent-light);
  display: inline-block;
}

h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  margin: 1.5rem 0 0.75rem;
}

/* Bio */
.bio {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
}

.bio a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.bio a:hover { border-bottom-color: var(--color-accent); }
.bio p + p { margin-top: 1rem; }

.hiring-notice {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, #eff6ff, #e0f0ff);
  border: 1px solid #a5c8e8;
  border-radius: 8px;
  padding: 0.75rem 1rem;
  margin-top: 1rem;
  font-size: 1rem;
}

/* News */
.news-list { list-style: none; }

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

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

.news-date {
  flex-shrink: 0;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-tag);
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  height: fit-content;
}

.news-content {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

.news-content a { color: var(--color-accent); text-decoration: none; }
.news-content a:hover { text-decoration: underline; }

/* Publications */
.pub-note {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  font-style: italic;
  margin-bottom: 1.5rem;
}

.publication {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
  transition: all 0.2s;
}

.publication:hover {
  border-color: var(--color-accent-light);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.pub-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  line-height: 1.45;
}

.pub-title a { color: var(--color-text); text-decoration: none; transition: color 0.2s; }
.pub-title a:hover { color: var(--color-accent); }

.pub-authors {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.55;
}

.pub-venue {
  font-size: 0.95rem;
  font-style: italic;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

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

.pub-links a {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  text-decoration: none;
  padding: 0.3rem 0.85rem;
  background: var(--color-tag);
  border-radius: 4px;
  transition: all 0.2s;
}

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

/* Talks */
.talks-list { list-style: none; }

.talk-item {
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.talk-item:last-child { border-bottom: none; }
.talk-item a { color: var(--color-accent); text-decoration: none; }
.talk-item a:hover { text-decoration: underline; }

/* Projects */
.project {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.75rem;
  gap: 1rem;
}

.project-title { font-size: 1.05rem; font-weight: 600; }
.project-links { display: flex; gap: 0.5rem; flex-shrink: 0; }

.project-links a {
  font-size: 0.85rem;
  color: var(--color-accent);
  text-decoration: none;
  padding: 0.25rem 0.7rem;
  background: var(--color-tag);
  border-radius: 4px;
  transition: all 0.2s;
}

.project-links a:hover { background: var(--color-accent); color: white; }
.project-desc { font-size: 1rem; color: var(--color-text-secondary); line-height: 1.65; }

/* Services */
.service-category { margin-bottom: 1rem; }
.service-title { font-weight: 600; font-size: 1rem; margin-bottom: 0.25rem; }
.service-content { font-size: 1rem; color: var(--color-text-secondary); }

/* Timeline */
.timeline-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
}

.timeline-item:last-child { border-bottom: none; }
.timeline-title a { color: var(--color-accent); text-decoration: none; }
.timeline-title a:hover { text-decoration: underline; }
.timeline-year { color: var(--color-text-secondary); flex-shrink: 0; margin-left: 1rem; }

/* Footer */
footer {
  margin-top: 4rem;
  padding: 2rem 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-content { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 1.5rem; }
.footer-content a { color: var(--color-accent); text-decoration: none; }
.footer-content a:hover { text-decoration: underline; }
.visitor-map { max-width: 300px; margin: 0 auto; }

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

/* Large Desktop */
@media (min-width: 1200px) {
  :root { --max-width: 1000px; }
  body { font-size: 20px; }
  .header-info h1 { font-size: 3.1rem; }
  .profile-image { width: 230px; }
  h2 { font-size: 1.85rem; }
}

/* Tablet */
@media (max-width: 1023px) {
  :root { --max-width: 720px; }
  body { font-size: 18px; }
  .container { padding: 0 1.5rem; }
  .header-info h1 { font-size: 2.35rem; }
  .profile-image { width: 180px; }
}

/* Mobile */
@media (max-width: 767px) {
  body { font-size: 17px; }
  .container { padding: 0 1rem; }
  header { padding: 2.5rem 0 2rem; }
  
  .header-content {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.5rem;
  }

  .header-info h1 { font-size: 1.85rem; }
  .affiliation { font-size: 1rem; }
  .location, .contact-email { font-size: 0.95rem; }
  .profile-image { width: 140px; min-height: 140px; height: auto; }
  .social-links { justify-content: center; }
  .social-links a { width: 38px; height: 38px; }

  nav ul { justify-content: flex-start; padding: 0.6rem 0; gap: 0; overflow-x: auto; }
  nav a { padding: 0.4rem 0.75rem; font-size: 0.85rem; }
  
  section { margin-bottom: 2.5rem; }
  h2 { font-size: 1.35rem; }
  h3 { font-size: 1.05rem; }
  .bio { font-size: 0.95rem; }
  
  .hiring-notice { flex-direction: column; align-items: flex-start; font-size: 0.9rem; padding: 0.75rem; }
  .news-item { flex-direction: column; gap: 0.5rem; padding: 0.85rem 0; }
  .news-date { align-self: flex-start; font-size: 0.8rem; padding: 0.2rem 0.6rem; }
  .news-content { font-size: 0.92rem; }
  
  .publication { padding: 1rem 1.15rem; }
  .pub-title { font-size: 0.98rem; }
  .pub-authors, .pub-venue { font-size: 0.88rem; }
  .pub-links a { font-size: 0.8rem; padding: 0.25rem 0.65rem; }
  
  .talk-item { font-size: 0.92rem; padding: 0.85rem 0; }
  .project { padding: 1rem 1.15rem; }
  .project-header { flex-direction: column; gap: 0.5rem; }
  .project-title { font-size: 0.98rem; }
  .project-links { align-self: flex-start; }
  .project-desc { font-size: 0.92rem; }
  .service-title, .service-content { font-size: 0.92rem; }
  
  .timeline-item { flex-direction: column; gap: 0.2rem; font-size: 0.92rem; padding: 0.65rem 0; }
  .timeline-year { margin-left: 0; font-size: 0.85rem; }
  
  footer { margin-top: 2.5rem; padding: 1.5rem 0; }
  .footer-content { font-size: 0.85rem; }
  .visitor-map { max-width: 250px; }
}

/* Small Mobile */
@media (max-width: 374px) {
  body { font-size: 15px; }
  .header-info h1 { font-size: 1.7rem; }
  .profile-image { width: 120px; min-height: 120px; }
  nav a { padding: 0.35rem 0.6rem; font-size: 0.85rem; }
}