/* =============================================
   GSCI – Global Strategic Corridors Institute
   Main Stylesheet
   ============================================= */

/* ---------- CSS Variables ---------- */
:root {
  --dark:        #0d1b2a;
  --navy:        #1a2f4b;
  --primary:     #1e3a5f;
  --gold:        #c9a227;
  --gold-light:  #e8c547;
  --white:       #ffffff;
  --off-white:   #f8f9fb;
  --bg-alt:      #f0f4f8;
  --text:        #2d3748;
  --text-light:  #6b7a8d;
  --border:      #dde3eb;
  --radius:      8px;
  --radius-lg:   16px;
  --shadow:      0 4px 24px rgba(13,27,42,0.10);
  --shadow-hover:0 8px 40px rgba(13,27,42,0.18);
  --transition:  0.35s ease;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5 {
  font-family: 'Playfair Display', 'Georgia', serif;
  line-height: 1.25;
  color: var(--dark);
}
h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 700; }
h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); font-weight: 600; }
h3 { font-size: 1.2rem; font-weight: 600; }
p  { font-size: 1rem; color: var(--text); }

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.5rem;
}
.section-title {
  margin-bottom: 0.75rem;
}
.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-light);
  max-width: 600px;
  margin: 0 auto 3rem;
}
.section-line {
  width: 48px;
  height: 3px;
  background: var(--gold);
  margin: 0.75rem auto 1.25rem;
  border-radius: 2px;
}
.text-center { text-align: center; }

/* ---------- Layout ---------- */
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}
section { padding: 96px 0; }

/* ---------- Scroll Reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* =============================================
   NAVIGATION
   ============================================= */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0 32px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background var(--transition), box-shadow var(--transition);
}
.nav.scrolled {
  background: rgba(13, 27, 42, 0.97);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.25);
}
.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.nav-logo-main {
  font-family: 'Playfair Display', serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.02em;
}
.nav-logo-en {
  font-family: 'Inter', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--white);
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.nav-logo-zh {
  font-size: 0.78rem;
  font-weight: 400;
  color: rgba(255,255,255,0.65);
  letter-spacing: 0.1em;
  white-space: nowrap;
}
.nav-logo-sub {
  font-size: 0.65rem;
  font-weight: 400;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: rgba(255,255,255,0.82);
  padding: 6px 12px;
  border-radius: 4px;
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover { color: var(--white); background: rgba(255,255,255,0.1); }
.nav-cta {
  background: var(--gold) !important;
  color: var(--dark) !important;
  font-weight: 600 !important;
  padding: 8px 20px !important;
  border-radius: 50px !important;
}
.nav-cta:hover { background: var(--gold-light) !important; }

/* Nav right group */
.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

/* Language toggle */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  background: rgba(255,255,255,0.10);
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: 50px;
  padding: 4px 10px;
}
.lang-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: rgba(255,255,255,0.5);
  padding: 2px 6px;
  border-radius: 50px;
  transition: all var(--transition);
  font-family: 'Inter', sans-serif;
  white-space: nowrap;
  touch-action: manipulation;
}
.lang-btn.active {
  background: var(--gold);
  color: var(--dark);
}
.lang-btn:hover:not(.active) {
  color: var(--white);
}
.lang-sep {
  color: rgba(255,255,255,0.25);
  font-size: 0.7rem;
  user-select: none;
}

/* Chinese font override */
body.lang-zh {
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}
body.lang-zh h1,
body.lang-zh h2,
body.lang-zh h3,
body.lang-zh h4 {
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-weight: 700;
  letter-spacing: 0.04em;
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  touch-action: manipulation;
  cursor: pointer;
  padding: 6px 4px;
  background: none;
  border: none;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: var(--transition);
  transform-origin: center;
}
/* Animated X when open */
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =============================================
   HERO
   ============================================= */
.hero {
  position: relative;
  height: 100vh;
  min-height: 640px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  text-align: center;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?auto=format&fit=crop&w=1920&q=80');
  background-size: cover;
  background-position: center;
  transform: scale(1.05);
  transition: transform 12s ease;
}
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    160deg,
    rgba(10, 22, 40, 0.78) 0%,
    rgba(13, 27, 42, 0.65) 60%,
    rgba(25, 50, 80, 0.55) 100%
  );
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 820px;
  padding: 0 24px;
}
.hero-badge {
  display: inline-flex;
  gap: 12px;
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.65);
  margin-bottom: 24px;
}
.hero-badge span { opacity: 0.4; }
.hero h1 {
  color: var(--white);
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  font-weight: 700;
  margin-bottom: 12px;
  text-shadow: 0 2px 20px rgba(0,0,0,0.4);
}
.hero-chinese {
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  color: rgba(255,255,255,0.72);
  letter-spacing: 0.1em;
  margin-bottom: 20px;
  font-weight: 300;
}
.hero-tagline {
  font-family: 'Playfair Display', serif;
  font-size: clamp(1rem, 2vw, 1.3rem);
  font-style: italic;
  color: var(--gold-light);
  margin-bottom: 40px;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--gold);
  color: var(--dark);
}
.btn-primary:hover { background: var(--gold-light); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(201,162,39,0.35); }
.btn-outline {
  background: transparent;
  color: var(--white);
  border: 1.5px solid rgba(255,255,255,0.5);
}
.btn-outline:hover { background: rgba(255,255,255,0.12); border-color: var(--white); transform: translateY(-2px); }
.hero-scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,0.5);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  animation: bounce 2.5s infinite;
}
.hero-scroll::after {
  content: '';
  display: block;
  width: 1.5px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(255,255,255,0.5), transparent);
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* =============================================
   STATS BAR
   ============================================= */
.stats-bar {
  background: var(--dark);
  padding: 0;
}
.stats-bar .container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  divide-x: 1px solid rgba(255,255,255,0.08);
}
.stat-item {
  padding: 44px 32px;
  text-align: center;
  border-right: 1px solid rgba(255,255,255,0.08);
  position: relative;
}
.stat-item:last-child { border-right: none; }
.stat-number {
  font-family: 'Playfair Display', serif;
  font-size: 3rem;
  font-weight: 700;
  color: var(--gold);
  line-height: 1;
  margin-bottom: 8px;
}
.stat-label {
  font-size: 0.82rem;
  font-weight: 500;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* =============================================
   ABOUT
   ============================================= */
.about { background: var(--white); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
  margin-top: 64px;
}
.about-text h3 {
  font-size: 1.05rem;
  color: var(--gold);
  font-weight: 600;
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-family: 'Inter', sans-serif;
}
.about-text p {
  font-size: 1.0rem;
  color: var(--text);
  margin-bottom: 32px;
  line-height: 1.8;
}
.about-text p:last-child { margin-bottom: 0; }
.about-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.about-card {
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  transition: all var(--transition);
  border-left: 4px solid var(--gold);
}
.about-card:hover {
  box-shadow: var(--shadow);
  transform: translateX(4px);
}
.about-card-title {
  font-family: 'Inter', sans-serif;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}
.about-card p {
  font-size: 0.925rem;
  color: var(--text-light);
  line-height: 1.7;
}

/* philosophy block */
.philosophy-block {
  margin-top: 64px;
  background: linear-gradient(135deg, var(--dark) 0%, var(--primary) 100%);
  border-radius: var(--radius-lg);
  padding: 56px 48px;
  text-align: center;
}
.philosophy-block .quote {
  font-family: 'Playfair Display', serif;
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-style: italic;
  color: var(--white);
  margin-bottom: 12px;
}
.philosophy-block .quote-sub {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.5);
}

/* =============================================
   RESEARCH AREAS
   ============================================= */
.research { background: var(--off-white); }
.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 56px;
}
.research-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}
.research-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}
.research-card-img {
  height: 200px;
  background-size: cover;
  background-position: center;
  position: relative;
}
.research-card-img::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(13,27,42,0.6) 0%, transparent 60%);
}
.research-card-body {
  padding: 24px 24px 28px;
}
.research-card-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 10px;
}
.research-card-body h3 {
  font-size: 1.1rem;
  color: var(--dark);
  margin-bottom: 10px;
}
.research-card-body p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.65;
}

/* Regional Focus */
.regional-focus {
  margin-top: 48px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
  text-align: center;
}
.regional-focus-label {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--text-light);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.regional-tags {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.regional-tag {
  padding: 8px 20px;
  border: 1.5px solid var(--primary);
  color: var(--primary);
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition);
}
.regional-tag:hover {
  background: var(--primary);
  color: var(--white);
}

/* =============================================
   PUBLICATIONS
   ============================================= */
.publications { background: var(--white); }
.pub-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px;
}
.pub-card {
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.pub-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--gold-light));
}
.pub-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-4px);
  border-color: var(--gold);
}
.pub-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--border);
  font-family: 'Playfair Display', serif;
  line-height: 1;
  margin-bottom: 16px;
  transition: color var(--transition);
}
.pub-card:hover .pub-number { color: var(--gold); }
.pub-card h3 {
  font-size: 1.0rem;
  color: var(--dark);
  margin-bottom: 12px;
  line-height: 1.4;
  flex: 1;
}
.pub-tag {
  display: inline-block;
  margin-top: 16px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-light);
  padding: 4px 12px;
  background: var(--border);
  border-radius: 50px;
}

/* =============================================
   EXPERTS
   ============================================= */
.experts { background: var(--off-white); }
.experts-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 56px;
}
.expert-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}
.expert-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.expert-avatar {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--dark));
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Playfair Display', serif;
  font-size: 1.4rem;
  color: var(--gold);
  font-weight: 600;
}
.expert-card h3 {
  font-size: 1rem;
  color: var(--dark);
  margin-bottom: 6px;
}
.expert-card p {
  font-size: 0.82rem;
  color: var(--text-light);
}
.expert-role {
  display: inline-block;
  margin-top: 10px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gold);
}
.expert-note {
  text-align: center;
  margin-top: 32px;
  font-size: 0.875rem;
  color: var(--text-light);
  font-style: italic;
}

/* =============================================
   PARTNERS
   ============================================= */
.partners { background: var(--white); }
.partners-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 56px;
}
.partner-item {
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: all var(--transition);
}
.partner-item:hover {
  border-color: var(--gold);
  box-shadow: 0 4px 16px rgba(201,162,39,0.12);
  transform: translateY(-2px);
}
.partner-item p {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--primary);
  line-height: 1.4;
}

/* =============================================
   EDUCATION
   ============================================= */
.education {
  background: linear-gradient(135deg, var(--dark) 0%, var(--navy) 100%);
  padding: 96px 0;
}
.education-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.education .section-label { color: var(--gold); }
.education h2 { color: var(--white); }
.education .section-line { margin-left: 0; }
.education p {
  color: rgba(255,255,255,0.72);
  font-size: 1rem;
  line-height: 1.85;
  margin-bottom: 20px;
}
.education p:last-child { margin-bottom: 0; }
.edu-feature {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  align-items: flex-start;
  gap: 18px;
  margin-bottom: 16px;
  transition: all var(--transition);
}
.edu-feature:hover { background: rgba(255,255,255,0.1); }
.edu-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: rgba(201,162,39,0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}
.edu-feature h4 {
  color: var(--white);
  font-family: 'Inter', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 6px;
}
.edu-feature p {
  font-size: 0.875rem;
  margin-bottom: 0;
  color: rgba(255,255,255,0.6);
}

/* =============================================
   CONTACT
   ============================================= */
.contact { background: var(--off-white); }
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  max-width: 700px;
  margin: 56px auto 0;
  align-items: start;
}
.contact-info h3 {
  font-size: 1.05rem;
  color: var(--dark);
  margin-bottom: 20px;
}
.contact-info p {
  font-size: 1rem;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 24px;
}
.contact-detail {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 16px;
  padding: 16px 20px;
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.contact-detail-icon {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: rgba(201,162,39,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.contact-detail-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.contact-detail-text strong {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-light);
}
.contact-detail-text a, .contact-detail-text span {
  font-size: 0.95rem;
  color: var(--primary);
  font-weight: 500;
}
.contact-detail-text a:hover { color: var(--gold); }
.contact-message {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow);
}
.contact-message h3 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}
.contact-message p {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-bottom: 28px;
  line-height: 1.7;
}
.email-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.email-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--primary);
  transition: all var(--transition);
}
.email-link:hover {
  border-color: var(--gold);
  background: rgba(201,162,39,0.05);
  color: var(--gold);
}
.email-link::before {
  content: '✉';
  font-size: 1rem;
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
  background: var(--dark);
  padding: 48px 0 32px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 40px;
}
.footer-brand .nav-logo-main { font-size: 1.1rem; margin-bottom: 8px; display: block; }
.footer-brand p {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.45);
  max-width: 300px;
  line-height: 1.7;
  margin-top: 10px;
}
.footer-col h4 {
  font-family: 'Inter', sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 16px;
}
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col ul a {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.55);
  transition: color var(--transition);
}
.footer-col ul a:hover { color: var(--white); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom p {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.35);
}

/* =============================================
   RESPONSIVE
   ============================================= */

/* --- Nav collapses to hamburger at 1080px --- */
@media (max-width: 1080px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 72px; left: 0; right: 0;
    background: rgba(13,27,42,0.98);
    backdrop-filter: blur(12px);
    padding: 20px 16px 28px;
    gap: 4px;
    border-top: 1px solid rgba(255,255,255,0.08);
    z-index: 999;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 16px; border-radius: 8px; font-size: 1rem; }
  .nav-toggle { display: flex; }
  .nav-logo-sub { display: none; }
  .nav-logo-zh { display: none; }
  .nav-logo-en { font-size: 0.82rem; }
}

/* --- Tablet & below layout adjustments --- */
@media (max-width: 1024px) {
  .experts-grid { grid-template-columns: repeat(2, 1fr); }
  .partners-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
  section { padding: 64px 0; }

  /* Shrink nav height; adjust drawer top to match */
  .nav { padding: 0 16px; height: 64px; }
  .nav-links { top: 64px; }

  .nav-right { gap: 10px; }
  .lang-toggle { padding: 3px 8px; }
  .lang-btn { font-size: 0.72rem; padding: 2px 5px; }

  .stats-bar .container { grid-template-columns: repeat(2, 1fr); }
  .stat-item { border-right: none; border-bottom: 1px solid rgba(255,255,255,0.08); }
  .stat-item:nth-child(odd) { border-right: 1px solid rgba(255,255,255,0.08); }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .research-grid { grid-template-columns: repeat(2, 1fr); }
  .pub-grid { grid-template-columns: repeat(2, 1fr); }
  .experts-grid { grid-template-columns: repeat(2, 1fr); }
  .partners-grid { grid-template-columns: repeat(2, 1fr); }
  .education-inner { grid-template-columns: 1fr; gap: 40px; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .philosophy-block { padding: 40px 28px; }
}

@media (max-width: 480px) {
  .research-grid { grid-template-columns: 1fr; }
  .pub-grid { grid-template-columns: 1fr; }
  .experts-grid { grid-template-columns: 1fr; }
  .partners-grid { grid-template-columns: 1fr; }
  .hero-buttons { flex-direction: column; align-items: center; }
}