/* ===== VARIABLES ===== */
:root {
  --primary:    #1a3a5c;   /* Deep navy */
  --accent:     #2e86c1;   /* Bright blue */
  --accent-light: #aed6f1;
  --text:       #2c3e50;
  --text-light: #7f8c8d;
  --bg:         #ffffff;
  --bg-alt:     #f4f6f9;
  --border:     #dce3ea;
  --success:    #27ae60;

  --font-body:  'Inter', sans-serif;
  --font-head:  'Merriweather', serif;
  --max-width:  960px;
  --radius:     8px;
  --shadow:     0 2px 12px rgba(0,0,0,0.08);
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

/* ===== CONTAINER ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== NAVBAR ===== */
.navbar {
  position: sticky;
  top: 0;
  background: var(--primary);
  z-index: 1000;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}
.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.nav-brand {
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.5px;
}
.nav-links {
  list-style: none;
  display: flex;
  gap: 1.8rem;
}
.nav-links a {
  color: rgba(255,255,255,0.85);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover,
.nav-links a.active {
  color: #fff;
  text-decoration: none;
  border-bottom: 2px solid var(--accent-light);
}
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.3rem;
  cursor: pointer;
}

/* ===== HERO ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #2c5282 100%);
  color: #fff;
  padding: 4rem 0 3rem;
}
.hero-content {
  display: flex;
  gap: 3rem;
  align-items: center;
}
.profile-img-wrapper {
  flex-shrink: 0;
}
.profile-img {
  width: 170px;
  height: 170px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid rgba(255,255,255,0.5);
  box-shadow: var(--shadow);
}
.profile-info h1 {
  font-family: var(--font-head);
  font-size: 2rem;
  margin-bottom: 0.3rem;
}
.profile-info .title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent-light);
}
.profile-info .dept,
.profile-info .university {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.8);
}
.research-interests {
  margin-top: 0.9rem;
  font-size: 0.9rem;
  color: rgba(255,255,255,0.9);
  line-height: 1.6;
}
.social-links {
  display: flex;
  gap: 0.9rem;
  margin-top: 1rem;
}
.social-links a {
  color: rgba(255,255,255,0.8);
  font-size: 1.3rem;
  transition: color 0.2s, transform 0.2s;
}
.social-links a:hover {
  color: #fff;
  transform: translateY(-2px);
  text-decoration: none;
}

/* ===== SECTIONS ===== */
.section { padding: 3.5rem 0; }
.section:nth-child(even) { background: var(--bg-alt); }

.section-title {
  font-family: var(--font-head);
  font-size: 1.5rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--accent);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.see-all {
  font-size: 0.85rem;
  font-family: var(--font-body);
  font-weight: 500;
}

/* ===== ABOUT ===== */
.about p { margin-bottom: 0.9rem; font-size: 0.97rem; }
.announcement {
  background: #eaf4fb;
  border-left: 4px solid var(--accent);
  padding: 0.9rem 1.2rem;
  border-radius: var(--radius);
  margin-top: 1.5rem;
  font-size: 0.9rem;
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
}
.announcement i { color: var(--accent); margin-top: 3px; }

/* ===== NEWS ===== */
.news-list { list-style: none; }
.news-list li {
  display: flex;
  gap: 1.2rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
  align-items: flex-start;
}
.news-date {
  flex-shrink: 0;
  width: 75px;
  color: var(--text-light);
  font-size: 0.82rem;
  padding-top: 2px;
  font-weight: 600;
}

/* ===== PUBLICATION CARD ===== */
.pub-card {
  display: flex;
  gap: 1rem;
  padding: 1.2rem;
  margin-bottom: 1rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: border-color 0.2s, box-shadow 0.2s;
}
.pub-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 16px rgba(46,134,193,0.15);
}
.pub-year {
  flex-shrink: 0;
  width: 48px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  padding-top: 2px;
}
.pub-title {
  font-weight: 600;
  font-size: 0.97rem;
  color: var(--primary);
  margin-bottom: 0.2rem;
}
.pub-authors {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 0.2rem;
}
.pub-authors .me { font-weight: 700; color: var(--text); }
.pub-venue {
  font-size: 0.85rem;
  font-style: italic;
  color: var(--text);
  margin-bottom: 0.5rem;
}
.pub-venue .venue-name {
  font-weight: 600;
  color: var(--primary);
}
.pub-badge {
  display: inline-block;
  padding: 1px 8px;
  font-size: 0.72rem;
  font-weight: 700;
  border-radius: 4px;
  margin-right: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  background: var(--accent);
  color: #fff;
}
.pub-badge.oral { background: #e74c3c; }
.pub-badge.best { background: #f39c12; }
.pub-links { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 0.5rem; }
.pub-link {
  font-size: 0.78rem;
  padding: 2px 10px;
  border: 1px solid var(--accent);
  border-radius: 20px;
  color: var(--accent);
  transition: all 0.2s;
}
.pub-link:hover {
  background: var(--accent);
  color: #fff;
  text-decoration: none;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--primary);
  color: rgba(255,255,255,0.7);
  text-align: center;
  padding: 2rem 1rem;
  font-size: 0.85rem;
}
.footer a { color: rgba(255,255,255,0.85); }
.footer-credit { margin-top: 0.3rem; font-size: 0.75rem; }

/* ===== RESPONSIVE ===== */
@media (max-width: 700px) {
  .hero-content { flex-direction: column; text-align: center; gap: 1.5rem; }
  .social-links { justify-content: center; }
  .nav-links { display: none; flex-direction: column; background: var(--primary); position: absolute; top: 60px; left: 0; right: 0; padding: 1rem 1.5rem; gap: 1rem; }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .pub-card { flex-direction: column; }
}