@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;1,9..40,300&display=swap');

:root {
  --primary: #1a2b4a;
  --accent: #4a7fa5;
  --accent-light: #e8f1f7;
  --text: #1e2a3a;
  --text-muted: #5c6b7a;
  --border: #dde4ea;
  --bg: #ffffff;
  --bg-soft: #f5f7fa;
  --nav-height: 68px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'DM Sans', sans-serif;
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.7;
}

/* NAV */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  display: flex;
  align-items: center;
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: 'DM Serif Display', serif;
  font-size: 1.35rem;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.01em;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 400;
  letter-spacing: 0.01em;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}

.nav-links .nav-internal a {
  color: var(--accent);
  font-weight: 500;
  border: 1px solid var(--accent);
  padding: 0.3rem 0.9rem;
  border-radius: 20px;
  transition: all 0.2s;
}

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

/* LAYOUT */
main {
  padding-top: var(--nav-height);
  min-height: 100vh;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

section {
  padding: 5rem 0;
}

/* HERO */
.hero {
  padding: 7rem 0 5rem;
  background: linear-gradient(160deg, #f5f8fb 0%, #ffffff 60%);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 1.2rem;
}

.hero h1 {
  font-family: 'DM Serif Display', serif;
  font-size: 3rem;
  line-height: 1.15;
  color: var(--primary);
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  font-weight: 300;
  margin-bottom: 2rem;
  line-height: 1.8;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2.5rem;
}

.tag {
  background: var(--accent-light);
  color: var(--accent);
  font-size: 0.8rem;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-weight: 400;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}

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

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

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text-muted);
  margin-left: 0.75rem;
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.hero-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.hero-stat {
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem;
  text-align: center;
}

.hero-stat:first-child {
  grid-column: 1 / -1;
  background: var(--primary);
  color: white;
}

.hero-stat .num {
  font-family: 'DM Serif Display', serif;
  font-size: 2.2rem;
  color: var(--accent);
  display: block;
}

.hero-stat:first-child .num {
  color: #a8c8e0;
}

.hero-stat .lbl {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.hero-stat:first-child .lbl {
  color: rgba(255,255,255,0.6);
}

/* SECTION TITLES */
.section-title {
  font-family: 'DM Serif Display', serif;
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--text-muted);
  font-weight: 300;
  margin-bottom: 3rem;
  font-size: 1rem;
}

.section-line {
  width: 40px;
  height: 2px;
  background: var(--accent);
  margin-bottom: 1rem;
}

/* NEWS */
.news-section { background: var(--bg-soft); }

.news-grid {
  display: grid;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.news-item {
  background: white;
  padding: 1.5rem 2rem;
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
}

.news-date {
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  padding-top: 0.15rem;
  min-width: 80px;
}

.news-badge {
  font-size: 0.7rem;
  font-weight: 500;
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  white-space: nowrap;
  margin-top: 0.1rem;
}

.badge-paper { background: #e8f4e8; color: #3a7d3a; }
.badge-award { background: #fef3cd; color: #856404; }
.badge-event { background: var(--accent-light); color: var(--accent); }
.badge-news { background: #f3e8f8; color: #7d3a9e; }

.news-text { font-size: 0.95rem; line-height: 1.6; }

/* MEMBERS */
.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.5rem;
}

.member-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  transition: border-color 0.2s, transform 0.2s;
}

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

.member-avatar {
  width: 100%;
  aspect-ratio: 1;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'DM Serif Display', serif;
  font-size: 2.2rem;
  color: var(--accent);
}

.member-info {
  padding: 1rem;
}

.member-name {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--primary);
  margin-bottom: 0.2rem;
}

.member-role {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.pi-card {
  border-color: var(--primary);
  background: #f8fafc;
}

/* PUBLICATIONS */
.pub-list { display: flex; flex-direction: column; gap: 1.25rem; }

.pub-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem 2rem;
  background: white;
  border-left: 3px solid var(--accent);
  transition: border-color 0.2s;
}

.pub-item:hover { border-left-color: var(--primary); }

.pub-title {
  font-weight: 500;
  font-size: 0.98rem;
  color: var(--primary);
  margin-bottom: 0.4rem;
  line-height: 1.5;
}

.pub-authors {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.pub-venue {
  font-size: 0.82rem;
  font-style: italic;
  color: var(--accent);
}

.pub-year-tag {
  float: right;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-soft);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}

/* PROJECTS */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.project-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  transition: border-color 0.2s, transform 0.2s;
}

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

.project-icon {
  width: 44px;
  height: 44px;
  background: var(--accent-light);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 1.2rem;
}

.project-title {
  font-weight: 500;
  font-size: 1rem;
  color: var(--primary);
  margin-bottom: 0.6rem;
}

.project-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* INTERNAL */
.internal-section {
  background: var(--primary);
  color: white;
  text-align: center;
  padding: 6rem 0;
}

.internal-section .section-title { color: white; }
.internal-section .section-subtitle { color: rgba(255,255,255,0.6); }

.lock-icon {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.btn-internal {
  background: var(--accent);
  color: white;
  padding: 0.9rem 2.5rem;
  border-radius: 4px;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  display: inline-block;
  transition: background 0.2s;
}

.btn-internal:hover { background: #3a6a8a; }

/* FOOTER */
footer {
  background: #0d1b2e;
  color: rgba(255,255,255,0.5);
  padding: 3rem 0;
  font-size: 0.85rem;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-logo {
  font-family: 'DM Serif Display', serif;
  font-size: 1.1rem;
  color: white;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .hero-inner { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero h1 { font-size: 2.2rem; }
  .footer-inner { flex-direction: column; gap: 1rem; text-align: center; }
  .nav-links { gap: 1rem; }
  .news-item { flex-direction: column; gap: 0.5rem; }
}