/* ── Sections (shared) ── */
section {
  position: relative;
  z-index: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: 7rem 6vw;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: .65rem;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}
.section-tag::before {
  content: '';
  display: block;
  width: 30px; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 2px;
}
.section-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(2rem, 4.5vw, 3.1rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 3.5rem;
}
.section-title em {
  font-style: normal;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: gradientShift 5s linear infinite;
}

/* Decorative section number */
.section-num { display: none; }

/* ── Glass card (premium) ── */
.glass {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(22px);
  -webkit-backdrop-filter: blur(22px);
  transition: border-color .35s, box-shadow .35s;
  overflow: hidden;
}

/* Shimmer sweep on hover */
.glass::before {
  content: '';
  position: absolute;
  top: 0; left: -110%;
  width: 55%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255,255,255,0.028), transparent);
  transition: left .65s ease;
  z-index: 1;
  pointer-events: none;
  border-radius: inherit;
}
.glass:hover::before { left: 155%; }

.glass:hover {
  border-color: rgba(0,240,255,.22);
  box-shadow:
    0 28px 80px rgba(0,0,0,.55),
    0 0 50px rgba(0,240,255,.065),
    inset 0 1px 0 rgba(255,255,255,0.09);
}

/* ── Sliding top accent bar (shared across all cards) ── */
.card-accent-bar {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s ease;
  border-radius: var(--radius) var(--radius) 0 0;
  z-index: 2;
}
.glass:hover .card-accent-bar { transform: scaleX(1); }

/* ── Divider ── */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(0,240,255,.22), rgba(191,0,255,.16), transparent);
  margin: 0 6vw;
}

/* ── Animations ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-in {
  opacity: 0;
  transform: translateY(38px);
  transition: opacity .8s ease, transform .8s ease;
}
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ── Responsive ── */
@media (max-width: 900px) {
  nav { top: .75rem; padding: .5rem .5rem .5rem 1.1rem; }
  .nav-links a { padding: .36rem .68rem; font-size: .75rem; }
  .about-grid { grid-template-columns: 1fr; }
  .research-grid { grid-template-columns: 1fr; }
  .section-num { display: none; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
  #hero { padding: 7rem 6vw 4rem; }
  .hero-stats { gap: 2rem; }
  .hero-name { font-size: clamp(3rem, 12vw, 4.5rem); }
}