/* ═══════════════════════════════════════════════
   LENS Lab — Laboratory for Energy and Nanoscale Science
   Stylesheet
   Color Palette (from slide template):
   - Deep Navy:    #0d2b4e
   - Mid Navy:     #0d4a7a
   - Primary Blue: #1e87c4
   - Light Blue:   #4da6d8
   - Accent Cyan:  #5ecce0
   - White:        #ffffff
   - Off-white:    #f0f6fb
   - Slate:        #7a97b3
═══════════════════════════════════════════════ */

/* ─── CSS Variables ─── */
:root {
  --navy-deep:   #0d2b4e;
  --navy-mid:    #0d4a7a;
  --blue-primary:#1e87c4;
  --blue-light:  #4da6d8;
  --blue-pale:   #a8d4ea;
  --cyan-accent: #5ecce0;
  --white:       #ffffff;
  --off-white:   #f0f6fb;
  --surface:     #e8f2f9;
  --slate-500:   #7a97b3;
  --slate-600:   #4e6e8e;
  --slate-700:   #2e4d6e;
  --text-dark:   #0d2b4e;
  --text-body:   #2e4d6e;
  --text-muted:  #7a97b3;
  --border:      #d0e4f0;
  --radius-sm:   6px;
  --radius-md:   12px;
  --radius-lg:   20px;
  --shadow-sm:   0 2px 8px rgba(13,75,122,0.08);
  --shadow-md:   0 6px 24px rgba(13,75,122,0.12);
  --shadow-lg:   0 16px 48px rgba(13,75,122,0.16);
  --transition:  0.3s ease;
  --max-w:       1520px;
}

/* ─── Reset & Base ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', 'Noto Sans KR', sans-serif;
  color: var(--text-body);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ─── Container ─── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 4rem;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
  white-space: nowrap;
}
.btn-primary {
  background: var(--blue-primary);
  color: #fff;
  border-color: var(--blue-primary);
}
.btn-primary:hover {
  background: var(--navy-mid);
  border-color: var(--navy-mid);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(30,135,196,0.35);
}
.btn-outline-white {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.5);
}
.btn-outline-white:hover {
  background: rgba(255,255,255,0.12);
  border-color: #fff;
}
.btn-outline-dark {
  background: transparent;
  color: var(--blue-primary);
  border-color: var(--blue-primary);
}
.btn-outline-dark:hover {
  background: var(--blue-primary);
  color: #fff;
}
.btn-full { width: 100%; justify-content: center; }
.btn-lg { padding: 0.9rem 2rem; font-size: 1rem; }

/* ─── Section base ─── */
.section { padding: 8rem 0; position: relative; }
.section-header { text-align: center; margin-bottom: 3.5rem; }
.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue-primary);
  background: rgba(30,135,196,0.08);
  padding: 0.35rem 1rem;
  border-radius: 999px;
  margin-bottom: 1rem;
}
.section-title {
  font-size: clamp(2rem, 3vw, 3rem);
  font-weight: 800;
  color: var(--navy-deep);
  line-height: 1.25;
  margin-bottom: 1rem;
}
.section-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ─── Gradient Text ─── */
.gradient-text {
  background: linear-gradient(135deg, var(--blue-primary), var(--cyan-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─── Animations ─── */
.fade-up { animation: fadeUp 0.9s ease both; }
.fade-up:nth-child(1) { animation-delay: 0.1s; }
.fade-up:nth-child(2) { animation-delay: 0.25s; }
.fade-up:nth-child(3) { animation-delay: 0.4s; }
.fade-up:nth-child(4) { animation-delay: 0.55s; }
.fade-up:nth-child(5) { animation-delay: 0.7s; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ══════════════════════════════════════
   NAVIGATION
══════════════════════════════════════ */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  transition: background 0.35s ease, box-shadow 0.35s ease;
}
.site-header.scrolled {
  background: rgba(13,27,48,0.97);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.3);
}
.site-header.light-nav {
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 16px rgba(13,75,122,0.1);
}
.site-header.light-nav .nav-link { color: var(--text-body); }
.site-header.light-nav .nav-link:hover,
.site-header.light-nav .nav-link.active { color: var(--blue-primary); }
.site-header.light-nav .nav-logo .logo-abbr { color: var(--navy-deep); }
.site-header.light-nav .nav-logo .logo-full { color: var(--text-muted); }
.site-header.light-nav .hamburger span { background: var(--navy-deep); }

.nav-container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 4rem;
  height: 72px;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}
.logo-text-wrap { display: flex; flex-direction: column; }
.logo-abbr {
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: 0.02em;
  line-height: 1.1;
}
.logo-full {
  font-size: 0.68rem;
  font-weight: 400;
  color: var(--blue-pale);
  letter-spacing: 0.03em;
  line-height: 1.2;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: auto;
}
.nav-link {
  padding: 0.5rem 1.1rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: rgba(255,255,255,0.8);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.nav-link:hover, .nav-link.active {
  color: #fff;
  background: rgba(255,255,255,0.1);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
  margin-left: auto;
}
.hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--transition);
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ══════════════════════════════════════
   HERO
══════════════════════════════════════ */
.hero-section {
  min-height: 100vh;
  background: linear-gradient(160deg, var(--navy-deep) 0%, #0a3560 40%, #0d6ba0 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding-top: 68px;
}

.hero-bg { position: absolute; inset: 0; pointer-events: none; }

.hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(78,166,216,0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(78,166,216,0.07) 1px, transparent 1px);
  background-size: 60px 60px;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.22;
}
.hero-orb-1 {
  width: 900px; height: 900px;
  background: radial-gradient(circle, var(--blue-primary), transparent);
  top: -200px; right: -150px;
}
.hero-orb-2 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, var(--cyan-accent), transparent);
  bottom: 0px; left: -120px;
}

#particle-canvas {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 5rem 2rem 3rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(94,204,224,0.15);
  border: 1px solid rgba(94,204,224,0.3);
  color: var(--cyan-accent);
  padding: 0.4rem 1.2rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 1.8rem;
}

.hero-title {
  font-size: clamp(2rem, 3.8vw, 4.2rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}
/* 70px fixed hero title */
.hero-title-large {
  font-size: 70px;
}
.hero-title-white {
  color: #ffffff;
}
@media (max-width: 1200px) {
  .hero-title-large { font-size: clamp(2.2rem, 5.5vw, 70px); }
}
@media (max-width: 768px) {
  .hero-title-large { font-size: clamp(1.8rem, 6vw, 2.8rem); }
}

/* PI section spacer */
.pi-section-spacer { height: 0.8rem; }

/* Publication meta simple (no citation) */
.pub-meta-simple {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0.4rem 0 0.8rem;
}

/* Publication link button — white bg + blue text by default, filled on hover */
.pub-btn-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 1.1rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--blue-primary) !important;
  background: #fff;
  border: 1.5px solid var(--blue-primary);
  transition: var(--transition);
  text-decoration: none;
  cursor: pointer;
}
.pub-btn-link:hover {
  background: var(--blue-primary);
  color: #fff !important;
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(30,135,196,0.22);
}
/* disabled link (Accepted, no URL yet) */
.pub-btn-nolink {
  color: var(--slate-500) !important;
  background: var(--off-white);
  border-color: var(--slate-500);
  cursor: default;
  pointer-events: none;
  opacity: 0.65;
}

/* Pagination */
.pub-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.4rem;
  margin: 2rem 0 1rem;
  flex-wrap: wrap;
}
.pg-btn {
  min-width: 38px;
  height: 38px;
  padding: 0 0.6rem;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: #fff;
  color: var(--text-body);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
}
.pg-btn:hover {
  border-color: var(--blue-primary);
  color: var(--blue-primary);
  background: rgba(30,135,196,0.05);
}
.pg-btn.active {
  background: var(--blue-primary);
  border-color: var(--blue-primary);
  color: #fff;
  font-weight: 700;
}
.pg-btn:disabled {
  opacity: 0.35;
  cursor: default;
  pointer-events: none;
}

.hero-desc {
  font-size: clamp(1.05rem, 1.5vw, 1.25rem);
  color: rgba(255,255,255,0.72);
  max-width: 760px;
  margin: 0 auto 2.5rem;
  line-height: 1.85;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: var(--radius-lg);
  padding: 2rem 4rem;
  backdrop-filter: blur(8px);
  flex-wrap: wrap;
}
.hero-stat {
  text-align: center;
  padding: 0.75rem 3.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.15rem;
}
.hero-stat > div:first-child {
  display: inline-flex;
  align-items: baseline;
}
.stat-num {
  font-size: 2.8rem;
  font-weight: 800;
  color: #fff;
  line-height: 1;
}
.hero-stat > span {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--cyan-accent);
  margin-left: 2px;
}
.stat-label {
  font-size: 0.82rem;
  font-weight: 500;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-top: 0.3rem;
}
.stat-sep {
  width: 1px;
  height: 40px;
  background: rgba(255,255,255,0.15);
  flex-shrink: 0;
}

/* Scroll indicator */
.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: rgba(255,255,255,0.4);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.scroll-mouse {
  width: 24px; height: 38px;
  border: 2px solid rgba(255,255,255,0.3);
  border-radius: 12px;
  display: flex;
  justify-content: center;
  padding-top: 6px;
}
.scroll-wheel {
  width: 4px; height: 8px;
  background: rgba(255,255,255,0.5);
  border-radius: 2px;
  animation: scrollAnim 2s ease infinite;
}
@keyframes scrollAnim {
  0% { transform: translateY(0); opacity: 1; }
  80% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ══════════════════════════════════════
   MEMBERS
══════════════════════════════════════ */
.members-section { background: var(--white); }

.member-tabs {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}
.m-tab {
  padding: 0.6rem 1.5rem;
  border: 2px solid var(--border);
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: var(--transition);
  background: #fff;
}
.m-tab:hover { border-color: var(--blue-light); color: var(--blue-primary); }
.m-tab.active {
  background: var(--blue-primary);
  border-color: var(--blue-primary);
  color: #fff;
}

.tab-content { display: none; }
.tab-content.active { display: block; }

/* PI Card */
.pi-card {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 4rem;
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 3.5rem;
  max-width: 100%;
  margin: 0 auto;
}
.pi-avatar-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}
.pi-avatar {
  width: 210px; height: 210px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--navy-mid), var(--blue-primary));
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 32px rgba(13,75,122,0.25);
}
.pi-avatar-inner { font-size: 4rem; color: rgba(255,255,255,0.7); }
.pi-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: linear-gradient(135deg, var(--blue-primary), var(--navy-mid));
  color: #fff;
  padding: 0.4rem 1.1rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}
.pi-name {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--navy-deep);
  margin-bottom: 0.25rem;
}
.pi-name-en {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-left: 0.5rem;
}
.pi-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--blue-primary);
  margin-bottom: 0.3rem;
}
.pi-dept {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  line-height: 1.5;
}
.pi-bio p {
  font-size: 0.95rem;
  color: var(--text-body);
  margin-bottom: 0.8rem;
  line-height: 1.75;
}
.pi-interests { margin: 1.5rem 0; }
.pi-interests h4 {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}
.tag-row { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag {
  background: rgba(30,135,196,0.08);
  color: var(--blue-primary);
  border: 1px solid rgba(30,135,196,0.2);
  padding: 0.3rem 0.85rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
}
.pi-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}
.pi-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.88rem;
  color: var(--blue-primary);
  font-weight: 500;
  transition: var(--transition);
}
.pi-link:hover { color: var(--navy-mid); text-decoration: underline; }

/* Member Cards */
.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.75rem;
}
.member-card {
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 1rem;
}
.member-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--blue-light);
}
.mc-avatar {
  width: 72px; height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: #fff;
}
/* PI photo */
.pi-avatar-photo {
  overflow: hidden;
  background: none;
  box-shadow: 0 4px 20px rgba(13,75,122,0.18);
}
.pi-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  border-radius: 50%;
  display: block;
}

/* 1×2 member grid */
.members-grid-2col {
  grid-template-columns: repeat(2, 1fr);
  max-width: 700px;
  margin: 0 auto;
}
@media (max-width: 600px) {
  .members-grid-2col { grid-template-columns: 1fr; }
}

.mc-blue   { background: linear-gradient(135deg, #1e87c4, #0d4a7a); }
.mc-indigo { background: linear-gradient(135deg, #4f46e5, #3730a3); }
.mc-teal   { background: linear-gradient(135deg, #0d9488, #0f766e); }
.mc-cyan   { background: linear-gradient(135deg, #0891b2, #0e7490); }
.mc-gray   { background: linear-gradient(135deg, #94a3b8, #64748b); }

.mc-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy-deep);
}
.mc-name span { font-size: 0.82rem; font-weight: 400; color: var(--text-muted); display: block; }
.mc-role { font-size: 0.82rem; font-weight: 600; color: var(--blue-primary); }
.mc-research { font-size: 0.85rem; color: var(--text-muted); }
.mc-links { display: flex; gap: 0.75rem; justify-content: center; margin-top: 0.25rem; }
.mc-links a {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  color: var(--blue-primary);
  transition: var(--transition);
}
.mc-links a:hover { background: var(--blue-primary); color: #fff; }
.join-card { border-style: dashed; background: rgba(30,135,196,0.02); }
.join-btn { color: var(--blue-primary); font-weight: 600; font-size: 0.9rem; }
.join-btn:hover { text-decoration: underline; }

/* Recruiting Banner */
.members-recruiting {
  text-align: center;
  padding: 3rem 2rem;
  background: linear-gradient(135deg, rgba(30,135,196,0.07) 0%, rgba(94,204,224,0.07) 100%);
  border: 1px solid rgba(30,135,196,0.2);
  border-radius: var(--radius-lg);
  margin-bottom: 2.5rem;
}
.recruiting-inner { max-width: 560px; margin: 0 auto; }
.recruiting-icon {
  width: 68px; height: 68px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-primary), var(--cyan-accent));
  display: flex; align-items: center; justify-content: center;
  font-size: 1.8rem; color: #fff;
  margin: 0 auto 1.25rem;
}
.members-recruiting h3 {
  font-size: 1.4rem; font-weight: 700;
  color: var(--navy-deep); margin-bottom: 0.75rem;
}
.members-recruiting p {
  font-size: 0.95rem; color: var(--text-body);
  line-height: 1.7; margin-bottom: 1.5rem;
}

/* Alumni Table */
.alumni-table-wrap { overflow-x: auto; }
.alumni-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}
.alumni-table th {
  background: var(--navy-deep);
  color: #fff;
  padding: 1rem 1.5rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.88rem;
  letter-spacing: 0.03em;
}
.alumni-table th:first-child { border-radius: var(--radius-sm) 0 0 0; }
.alumni-table th:last-child  { border-radius: 0 var(--radius-sm) 0 0; }
.alumni-table td {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-body);
}
.alumni-table tr:last-child td { border-bottom: none; }
.alumni-table tbody tr { background: var(--off-white); transition: var(--transition); }
.alumni-table tbody tr:hover { background: var(--surface); }
.alumni-table tbody tr:nth-child(even) { background: var(--white); }
.alumni-table tbody tr:nth-child(even):hover { background: var(--surface); }

/* ══════════════════════════════════════
   RESEARCH
══════════════════════════════════════ */
.research-section { background: var(--off-white); }
.research-bg-deco {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 6px;
  background: linear-gradient(90deg, var(--blue-primary), var(--cyan-accent), var(--blue-light));
}

.research-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 4rem;
}
.research-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.research-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-primary), var(--cyan-accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}
.research-card:hover::before { transform: scaleX(1); }
.research-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.rc-icon-wrap {
  width: 60px; height: 60px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  color: #fff;
}
.rc-solar      { background: linear-gradient(135deg, #f59e0b, #d97706); }
.rc-battery    { background: linear-gradient(135deg, var(--blue-primary), var(--navy-mid)); }
.rc-nano       { background: linear-gradient(135deg, var(--cyan-accent), #0891b2); }
.rc-hydrogen   { background: linear-gradient(135deg, #10b981, #059669); }
/* new research area colours */
.rc-mechanism  { background: linear-gradient(135deg, #8b5cf6, #6d28d9); }
.rc-interface  { background: linear-gradient(135deg, #0891b2, #0e7490); }
.rc-tem        { background: linear-gradient(135deg, #0d4a7a, #1e87c4); }

.rc-num {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}
.rc-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--navy-deep);
  margin-bottom: 0.75rem;
  line-height: 1.4;
}
.rc-desc {
  font-size: 0.93rem;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 1.25rem;
}
.rc-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.rc-keywords span {
  background: var(--surface);
  color: var(--slate-600);
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--border);
}

/* Equipment */
.equipment-section {
  background: var(--navy-deep);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}
.equip-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1.5rem;
  text-align: center;
}
.equip-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1.25rem;
}
.equip-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: var(--transition);
}
.equip-item:hover {
  background: rgba(30,135,196,0.2);
  border-color: var(--blue-light);
}
.equip-item i { font-size: 1.5rem; color: var(--cyan-accent); }
.equip-item span { font-size: 0.85rem; font-weight: 600; color: rgba(255,255,255,0.8); text-align: center; }

/* ══════════════════════════════════════
   PUBLICATIONS
══════════════════════════════════════ */
.publications-section { background: var(--white); }

.pub-filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}
.pf-btn {
  padding: 0.5rem 1.2rem;
  border: 2px solid var(--border);
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  background: #fff;
  transition: var(--transition);
}
.pf-btn:hover { border-color: var(--blue-light); color: var(--blue-primary); }
.pf-btn.active { background: var(--blue-primary); border-color: var(--blue-primary); color: #fff; }

.pub-list { display: flex; flex-direction: column; gap: 1.25rem; margin-bottom: 2.5rem; }

.pub-item {
  display: flex;
  gap: 2rem;
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 2rem 2.5rem;
  transition: var(--transition);
}
.pub-item:hover { box-shadow: var(--shadow-md); border-color: var(--blue-pale); }
.pub-item.hidden { display: none; }

.pub-year-badge {
  flex-shrink: 0;
  width: 52px; height: 52px;
  background: linear-gradient(135deg, var(--blue-primary), var(--navy-mid));
  color: #fff;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  text-align: center;
}

.pub-body { flex: 1; }
.pub-journal-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.6rem;
  flex-wrap: wrap;
}
.pub-journal {
  display: inline-block;
  padding: 0.22rem 0.8rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.journal-nature { background: #d4edda; color: #155724; }
.journal-acs    { background: #cce5ff; color: #004085; }
.journal-adv    { background: #fff3cd; color: #856404; }
.journal-nano   { background: #e2d9f3; color: #4a235a; }
.journal-joule  { background: #fde8d8; color: #7c2d00; }

.pub-type {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}
.pub-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy-deep);
  line-height: 1.5;
  margin-bottom: 0.5rem;
}
.pub-authors {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}
.pub-meta {
  display: flex;
  gap: 1.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
}
.pub-meta i { margin-right: 0.3rem; color: var(--blue-light); }
.pub-actions { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.pub-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--blue-primary);
  background: #fff;
  transition: var(--transition);
}
.pub-btn:hover { background: var(--blue-primary); color: #fff; border-color: var(--blue-primary); }

.pub-more { text-align: center; }

/* ══════════════════════════════════════
   NEWS
══════════════════════════════════════ */
.news-section { background: var(--off-white); }
.news-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent, rgba(13,43,78,0.03));
  pointer-events: none;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-template-rows: auto auto;
  gap: 1.75rem;
}
.news-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.news-card::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-primary), var(--cyan-accent));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}
.news-card:hover::after { transform: scaleX(1); }
.news-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.news-featured {
  grid-column: span 7;
}
.news-grid .news-card:not(.news-featured) {
  grid-column: span 5;
}
.news-grid .news-card:nth-child(3) { grid-column: span 5; }
.news-grid .news-card:nth-child(4) { grid-column: span 4; }
.news-grid .news-card:nth-child(5) { grid-column: span 4; }
.news-grid .news-card:nth-child(6) { grid-column: span 4; }

.nc-badge {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}
.nc-badge-new { background: var(--blue-primary); color: #fff; }

.nc-date {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.nc-category {
  display: inline-block;
  background: rgba(30,135,196,0.08);
  color: var(--blue-primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 0.75rem;
}
.nc-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy-deep);
  line-height: 1.45;
  margin-bottom: 0.75rem;
}
.news-featured .nc-title { font-size: 1.3rem; }
.nc-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 1rem;
}
.nc-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--blue-primary);
  transition: var(--transition);
}
.nc-link:hover { gap: 0.7rem; }

/* ══════════════════════════════════════
   GALLERY
══════════════════════════════════════ */
.gallery-section { background: var(--white); }

.gallery-filter {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}
.gf-btn {
  padding: 0.5rem 1.25rem;
  border: 2px solid var(--border);
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  background: #fff;
  transition: var(--transition);
}
.gf-btn:hover { border-color: var(--blue-light); color: var(--blue-primary); }
.gf-btn.active { background: var(--blue-primary); border-color: var(--blue-primary); color: #fff; }

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-auto-rows: 260px;
  gap: 1.25rem;
}
.gallery-item.hidden { display: none; }
.gi-inner {
  border-radius: var(--radius-md);
  overflow: hidden;
  position: relative;
  height: 100%;
  cursor: pointer;
}
.gi-inner.gi-tall { grid-row: span 2; }
.gi-inner.gi-wide { grid-column: span 2; }

.gi-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  transition: transform 0.4s ease;
}
.gi-inner:hover .gi-placeholder { transform: scale(1.04); }
.gi-placeholder i { font-size: 2.5rem; opacity: 0.7; color: #fff; }
.gi-placeholder span { font-size: 0.9rem; font-weight: 600; color: rgba(255,255,255,0.85); }

.gi-color-1 { background: linear-gradient(135deg, #0d4a7a, #1e87c4); }
.gi-color-2 { background: linear-gradient(135deg, #1e87c4, #5ecce0); }
.gi-color-3 { background: linear-gradient(135deg, #0f766e, #0d9488); }
.gi-color-4 { background: linear-gradient(135deg, #0d2b4e, #0d4a7a); }
.gi-color-5 { background: linear-gradient(135deg, #0891b2, #1e87c4); }
.gi-color-6 { background: linear-gradient(135deg, #4f46e5, #1e87c4); }

.gi-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(13,27,48,0.85) 0%, transparent 55%);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.gi-inner:hover .gi-overlay { opacity: 1; }
.gi-text { font-size: 0.95rem; font-weight: 700; color: #fff; }
.gi-sub  { font-size: 0.78rem; color: rgba(255,255,255,0.65); margin-top: 0.2rem; }

/* ══════════════════════════════════════
   CONTACT
══════════════════════════════════════ */
.contact-section { background: var(--off-white); }

.contact-layout {
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 4rem;
  margin-bottom: 3rem;
}

.ci-card {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
}
.ci-icon {
  width: 42px; height: 42px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--blue-primary), var(--navy-mid));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}
.ci-card h4 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.25rem;
}
.ci-card p { font-size: 0.92rem; color: var(--text-body); line-height: 1.6; }
.ci-card a { color: var(--blue-primary); }
.ci-card a:hover { text-decoration: underline; }

.recruitment-box {
  background: linear-gradient(135deg, var(--navy-deep), var(--navy-mid));
  border-radius: var(--radius-md);
  padding: 1.75rem;
  color: #fff;
  margin-top: 1rem;
}
.rb-icon {
  width: 48px; height: 48px;
  background: rgba(94,204,224,0.2);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: var(--cyan-accent);
  margin-bottom: 1rem;
}
.recruitment-box h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}
.recruitment-box p {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.72);
  line-height: 1.7;
  margin-bottom: 1rem;
}
.rb-list { display: flex; flex-direction: column; gap: 0.5rem; }
.rb-list li {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.85);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.rb-list i { color: var(--cyan-accent); font-size: 0.8rem; }

/* Contact Form */
.contact-form-wrap {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}
.form-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-group { margin-bottom: 1.25rem; }
.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-body);
  margin-bottom: 0.4rem;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.93rem;
  font-family: inherit;
  color: var(--text-dark);
  background: var(--white);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  outline: none;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--blue-primary);
  box-shadow: 0 0 0 3px rgba(30,135,196,0.15);
}
.form-group textarea { resize: vertical; }
.form-check {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}
.form-check input { width: auto; }
.form-check label { font-size: 0.88rem; margin-bottom: 0; font-weight: 400; color: var(--text-muted); }

.form-success-msg {
  text-align: center;
  padding: 3rem 1rem;
}
.success-icon { font-size: 3rem; color: #10b981; margin-bottom: 1rem; }
.form-success-msg h4 { font-size: 1.3rem; font-weight: 700; color: var(--navy-deep); margin-bottom: 0.5rem; }
.form-success-msg p  { color: var(--text-muted); }

/* Map */
.map-placeholder {
  background: var(--navy-deep);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.map-inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  color: rgba(255,255,255,0.85);
}
.map-inner i { font-size: 2.5rem; color: var(--cyan-accent); }
.map-inner strong { color: #fff; }
.map-inner p, .map-inner div { font-size: 0.92rem; line-height: 1.65; }

/* ══════════════════════════════════════
   FOOTER
══════════════════════════════════════ */
.site-footer {
  background: var(--navy-deep);
  color: rgba(255,255,255,0.7);
  padding: 3.5rem 0 2rem;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2.5fr 1fr 1fr 1.5fr;
  gap: 4rem;
}
.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.15rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.75rem;
}
.footer-desc {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.55);
  line-height: 1.7;
  margin-bottom: 1rem;
}
.footer-copy { font-size: 0.8rem; color: rgba(255,255,255,0.35); }
.footer-nav-col h5, .footer-contact-col h5 {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--blue-pale);
  margin-bottom: 1rem;
}
.footer-nav-col ul li { margin-bottom: 0.6rem; }
.footer-nav-col ul a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.6);
  transition: var(--transition);
}
.footer-nav-col ul a:hover { color: #fff; }
.footer-contact-col p {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.6);
  margin-bottom: 0.6rem;
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  line-height: 1.5;
}
.footer-contact-col i { color: var(--blue-light); margin-top: 3px; flex-shrink: 0; }
.footer-social {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
}
.footer-social a {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.65);
  font-size: 0.88rem;
  transition: var(--transition);
}
.footer-social a:hover {
  background: var(--blue-primary);
  border-color: var(--blue-primary);
  color: #fff;
  transform: translateY(-2px);
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 2rem; right: 2rem;
  width: 44px; height: 44px;
  background: var(--blue-primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  box-shadow: var(--shadow-md);
  z-index: 500;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}
.back-to-top.visible {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}
.back-to-top:hover {
  background: var(--navy-mid);
  transform: translateY(-3px);
}

/* ══════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════ */
@media (max-width: 1600px) {
  :root { --max-w: 1320px; }
  .container { padding: 0 3rem; }
  .nav-container { padding: 0 3rem; }
  .research-grid { grid-template-columns: repeat(4, 1fr); }
  .equip-grid { grid-template-columns: repeat(6, 1fr); }
  .footer-inner { grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 3rem; }
}

@media (max-width: 1280px) {
  :root { --max-w: 1100px; }
  .container { padding: 0 2.5rem; }
  .nav-container { padding: 0 2.5rem; }
  .research-grid { grid-template-columns: repeat(2, 1fr); }
  .equip-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-inner { grid-template-columns: 2fr 1fr 1.5fr; gap: 2.5rem; }
  .footer-left { grid-column: span 1; }
  .contact-layout { grid-template-columns: 380px 1fr; gap: 3rem; }
}

@media (max-width: 1024px) {
  .pi-card { grid-template-columns: 200px 1fr; gap: 2rem; }
  .contact-layout { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-left { grid-column: span 2; }

  .news-featured { grid-column: span 12; }
  .news-grid .news-card:not(.news-featured) { grid-column: span 6; }
  .news-grid .news-card:nth-child(3) { grid-column: span 6; }
  .news-grid .news-card:nth-child(4) { grid-column: span 4; }
  .news-grid .news-card:nth-child(5) { grid-column: span 4; }
  .news-grid .news-card:nth-child(6) { grid-column: span 4; }
}

@media (max-width: 768px) {
  .section { padding: 4rem 0; }
  .container { padding: 0 1.5rem; }
  .nav-container { padding: 0 1.5rem; }

  .nav-links { display: none; }
  .hamburger { display: flex; }

  /* Mobile menu overlay */
  .mobile-nav-open .nav-links {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: 0;
    background: rgba(13,27,48,0.98);
    backdrop-filter: blur(16px);
    z-index: 999;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    padding-top: 68px;
  }
  .mobile-nav-open .nav-link {
    font-size: 1.4rem;
    padding: 0.5rem 1.5rem;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1rem;
    padding: 1.5rem;
  }
  .stat-sep { display: none; }

  .pi-card { grid-template-columns: 1fr; text-align: center; }
  .pi-avatar-wrap { align-items: center; }
  .pi-links { justify-content: center; }

  .news-grid { grid-template-columns: 1fr; }
  .news-featured { grid-column: span 1; }
  .news-grid .news-card:not(.news-featured),
  .news-grid .news-card:nth-child(3),
  .news-grid .news-card:nth-child(4),
  .news-grid .news-card:nth-child(5),
  .news-grid .news-card:nth-child(6) { grid-column: span 1; }

  .gallery-grid {
    grid-template-columns: 1fr 1fr;
    grid-auto-rows: 160px;
  }

  .form-grid-2 { grid-template-columns: 1fr; }

  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-left { grid-column: span 1; }

  .hero-cta { flex-direction: column; align-items: center; }

  .pub-item { flex-direction: column; gap: 1rem; }
  .pub-year-badge { width: auto; height: auto; padding: 0.3rem 0.75rem; align-self: flex-start; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 2rem; }
  .section-title { font-size: 1.6rem; }
  .gallery-grid { grid-template-columns: 1fr; grid-auto-rows: 200px; }
  .gi-inner.gi-tall { grid-row: span 1; }
  .gi-inner.gi-wide { grid-column: span 1; }
  .equip-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-stats { padding: 1.25rem; }
  .hero-stat { padding: 0.5rem 1rem; }
  .research-grid { grid-template-columns: 1fr; }
}