/* ============================================================
   Doyun Lee Lab — Main Stylesheet
   ============================================================ */

:root {
  --primary:      #1a3a5c;
  --primary-dark: #0f2238;
  --accent:       #2e7bbf;
  --accent-light: #4a9fd4;
  --text:         #1f2937;
  --text-muted:   #6b7280;
  --bg-light:     #f8fafc;
  --border:       #e5e7eb;
  --white:        #ffffff;
  --font-sans:    'Inter', sans-serif;
  --font-serif:   'Merriweather', serif;
  --radius:       0.5rem;
  --shadow:       0 4px 20px rgba(0,0,0,0.08);
  --shadow-hover: 0 8px 30px rgba(0,0,0,0.14);
}

/* ── Base ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}

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

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.25;
  color: var(--primary);
}

/* ── Navbar ───────────────────────────────────── */
#main-navbar {
  background-color: var(--primary);
  padding: 0.75rem 0;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
  transition: background-color 0.3s;
}

.navbar-brand {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.01em;
}

.brand-sub {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.65);
  font-weight: 400;
}

.nav-link {
  color: rgba(255,255,255,0.85) !important;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.5rem 0.9rem !important;
  border-radius: var(--radius);
  transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--white) !important;
  background: rgba(255,255,255,0.12);
}

/* ── Page Hero (inner pages) ──────────────────── */
.page-hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  padding: 3.5rem 0 2.5rem;
  color: var(--white);
}

.page-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 0.25rem;
}

.page-subtitle {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.8);
  margin: 0;
}

.page-content {
  padding: 3rem 0 5rem;
}

/* ── Section Utilities ────────────────────────── */
.section { padding: 5rem 0; }
.section-alt { background: var(--bg-light); }

.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin-bottom: 0.5rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.section-lead {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-top: 1rem;
  max-width: 680px;
}

/* ── Homepage Hero ────────────────────────────── */
.hero-section {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--accent) 100%);
  color: var(--white);
  min-height: 520px;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('../images/banner_haeundae.jpg') center/cover no-repeat;
  opacity: 0.18;
}

.hero-content { position: relative; z-index: 1; }

.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  color: var(--white);
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero-title .highlight { color: #7dd3fc; }

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: rgba(255,255,255,0.85);
  margin-bottom: 2rem;
  max-width: 580px;
  line-height: 1.6;
}

.hero-badges { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 2rem; }

.hero-badge {
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.3);
  color: var(--white);
  padding: 0.3rem 0.9rem;
  border-radius: 999px;
  font-size: 0.85rem;
  backdrop-filter: blur(4px);
}

.hero-stats {
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.hero-stat-num {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--white);
  line-height: 1;
  display: block;
}

.hero-stat-label {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.7);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: block;
}

/* ── Research Cards ───────────────────────────── */
.research-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 2rem;
  height: 100%;
  border: 1px solid var(--border);
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}

.research-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 4px; height: 100%;
  background: var(--accent);
  transform: scaleY(0);
  transition: transform 0.3s;
  transform-origin: bottom;
}

.research-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: var(--accent-light);
}

.research-card:hover::before { transform: scaleY(1); }

.research-icon {
  width: 52px; height: 52px;
  background: rgba(46, 123, 191, 0.1);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.4rem;
  color: var(--accent);
}

.research-card h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--primary);
}

.research-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin: 0;
}

/* ── Member Cards ─────────────────────────────── */
.member-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: all 0.3s;
  text-align: center;
}

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

.member-photo-wrap {
  width: 140px; height: 140px;
  border-radius: 50%;
  overflow: hidden;
  margin: 1.75rem auto 1rem;
  border: 3px solid var(--border);
}

.member-photo-wrap img {
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center 15%;
}

.member-photo-placeholder {
  width: 100%; height: 100%;
  background: linear-gradient(135deg, #dde6f0, #b8cfe8);
  display: flex; align-items: center; justify-content: center;
  font-size: 2.5rem; color: var(--accent);
}

.member-card-body { padding: 0 1.5rem 1.75rem; }

.member-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.2rem;
}

.member-role {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.6rem;
}

.member-info {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.member-links a {
  color: var(--text-muted);
  margin: 0 0.3rem;
  font-size: 1.1rem;
  transition: color 0.2s;
}

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

/* ── PI Card ──────────────────────────────────── */
.pi-card {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: var(--radius);
  padding: 2.5rem;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.pi-card::after {
  content: '';
  position: absolute;
  right: -40px; top: -40px;
  width: 180px; height: 180px;
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
}

.pi-photo {
  width: 120px; height: 120px;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid rgba(255,255,255,0.4);
  margin-bottom: 1rem;
}

.pi-photo img { width: 100%; height: 100%; object-fit: cover; }

.pi-name { font-size: 1.5rem; font-weight: 700; color: var(--white); margin-bottom: 0.15rem; }
.pi-title { font-size: 0.9rem; color: rgba(255,255,255,0.8); margin-bottom: 1rem; }
.pi-bio { font-size: 0.92rem; color: rgba(255,255,255,0.9); line-height: 1.7; }

/* ── Publication List ─────────────────────────── */
.pub-year-group { margin-bottom: 2.5rem; }

.pub-year-label {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
  border-bottom: 2px solid var(--accent);
  padding-bottom: 0.4rem;
  margin-bottom: 1.25rem;
  display: inline-block;
}

.pub-item {
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 0.75rem;
  background: var(--white);
  transition: all 0.2s;
  position: relative;
  padding-left: 1.75rem;
}

.pub-item::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--accent);
  border-radius: var(--radius) 0 0 var(--radius);
}

.pub-item:hover {
  box-shadow: var(--shadow);
  border-color: var(--accent-light);
}

.pub-title {
  font-size: 0.97rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.35rem;
}

.pub-authors {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}

.pub-authors strong { color: var(--primary-dark); }

.pub-journal {
  font-size: 0.88rem;
  font-style: italic;
  color: var(--accent);
}

.pub-badges { margin-top: 0.6rem; }

.pub-badge {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  margin-right: 0.35rem;
  font-weight: 500;
}

.pub-badge-pdf {
  background: #fef2f2;
  color: #ef4444;
  border: 1px solid #fecaca;
}

.pub-badge-doi {
  background: #eff6ff;
  color: var(--accent);
  border: 1px solid #bfdbfe;
}

/* ── News / Posts ─────────────────────────────── */
.news-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.3s;
  height: 100%;
}

.news-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-3px); }

.news-card-body { padding: 1.5rem; }

.news-date {
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.3rem;
  margin-bottom: 0.5rem;
}

.news-card h5 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
  color: var(--primary);
}

.news-card h5 a { color: inherit; }
.news-card h5 a:hover { color: var(--accent); text-decoration: none; }

.news-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin: 0;
}

.news-card-thumbnail {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
}

.post-meta {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.75);
  margin-top: 0.5rem;
}

.post-body {
  font-size: 1rem;
  line-height: 1.8;
}

.post-body h2, .post-body h3 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

/* ── Positions ────────────────────────────────── */
.position-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all 0.3s;
  height: 100%;
}

.position-card:hover {
  box-shadow: var(--shadow-hover);
  border-color: var(--accent-light);
}

.position-icon {
  width: 56px; height: 56px;
  background: rgba(46, 123, 191, 0.1);
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
  color: var(--accent);
  margin-bottom: 1.25rem;
}

.position-card h4 { font-size: 1.1rem; font-weight: 600; margin-bottom: 0.75rem; }

/* ── Contact ──────────────────────────────────── */
.contact-info-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}

.contact-info-item {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  align-items: flex-start;
}

.contact-icon {
  width: 44px; height: 44px; min-width: 44px;
  background: rgba(46, 123, 191, 0.1);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem; color: var(--accent);
}

.contact-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.contact-value { font-size: 0.95rem; color: var(--text); margin: 0; }

/* ── Footer ───────────────────────────────────── */
.site-footer {
  background: var(--primary-dark);
  color: rgba(255,255,255,0.7);
  padding: 3.5rem 0 1.5rem;
}

.footer-heading {
  color: var(--white);
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.footer-desc, .footer-affil {
  font-size: 0.85rem;
  line-height: 1.6;
  margin-bottom: 0.5rem;
}

.footer-address p {
  font-size: 0.85rem;
  margin-bottom: 0.4rem;
}

.footer-address a { color: rgba(255,255,255,0.7); }
.footer-address a:hover { color: var(--white); }

.footer-links li { margin-bottom: 0.35rem; }

.footer-links a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.6);
}

.footer-links a:hover { color: var(--white); text-decoration: none; }

.footer-divider {
  border-color: rgba(255,255,255,0.1);
  margin: 2rem 0 1.25rem;
}

.footer-bottom p {
  font-size: 0.8rem;
  margin: 0;
  color: rgba(255,255,255,0.45);
}

/* ── Alumni Table ─────────────────────────────── */
.alumni-section .table {
  font-size: 0.9rem;
}

.alumni-section .table th {
  font-weight: 600;
  color: var(--primary);
  border-bottom: 2px solid var(--accent);
  white-space: nowrap;
}

/* ── Alumni Cards ─────────────────────────────── */
.alumni-card {
  display: flex;
  gap: 1.25rem;
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 1.25rem;
  transition: all 0.3s;
  height: 100%;
}

.alumni-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.alumni-photo-wrap {
  flex: 0 0 110px;
  width: 110px; height: 130px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #f3f5f8;
}

.alumni-photo-wrap img {
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center 15%;
}

.alumni-photo-placeholder {
  width: 100%; height: 100%;
  background: linear-gradient(135deg, #dde6f0, #b8cfe8);
  display: flex; align-items: center; justify-content: center;
  font-size: 2rem; color: var(--accent);
}

.alumni-info { flex: 1; min-width: 0; }

.alumni-name {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.15rem;
}

.alumni-role {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.6rem;
}

.alumni-current {
  font-size: 0.88rem;
  color: var(--text);
  margin-bottom: 0.6rem;
  line-height: 1.45;
}

.alumni-section-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0.5rem 0 0.25rem;
}

.alumni-list {
  list-style: disc;
  margin: 0 0 0.5rem 1.1rem;
  padding: 0;
}

.alumni-list li {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.2rem;
}

@media (max-width: 575px) {
  .alumni-card { flex-direction: column; }
  .alumni-photo-wrap { width: 110px; }
}

/* ── Responsive ───────────────────────────────── */
@media (max-width: 768px) {
  .hero-section { min-height: 420px; }
  .hero-stats { gap: 1.5rem; }
  .pi-card { padding: 1.75rem; }
}