/* ═══════════════════════════════════════════════════════════
   NAVIGATION — Tab Bar
   ═══════════════════════════════════════════════════════════ */

.nav {
  display: flex;
  align-items: center;
  background: rgba(10, 14, 22, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0 var(--space-2);
  height: var(--nav-h);
  position: sticky;
  top: 0;
  z-index: var(--z-map-controls);
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}

.nav::-webkit-scrollbar {
  display: none;
}

.nav-btn {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0 var(--space-4);
  height: calc(var(--nav-h) - 2px);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
  border-radius: var(--radius-sm);
  transition: color var(--duration-fast) var(--ease-out),
              background var(--duration-fast) var(--ease-out);
}

.nav-btn:hover {
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.03);
}

.nav-btn.active {
  color: var(--accent-primary);
}

.nav-btn.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: var(--space-3);
  right: var(--space-3);
  height: 2px;
  background: var(--accent-primary);
  border-radius: var(--radius-full) var(--radius-full) 0 0;
  box-shadow: 0 0 12px var(--accent-glow);
}

.nav-btn__icon {
  width: 15px;
  height: 15px;
  opacity: 0.7;
}

.nav-btn.active .nav-btn__icon {
  opacity: 1;
}

/* ── Responsive ── */
@media (max-width: 767px) {
  .nav {
    padding: 0;
    gap: 0;
  }

  .nav-btn {
    flex: 1;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 0;
    gap: 2px;
    min-height: 40px;
  }

  .nav-btn__label {
    display: block;
    font-size: 8px;
    letter-spacing: 0.04em;
  }

  .nav-btn__icon {
    width: 16px;
    height: 16px;
  }

  .nav-btn.active::after {
    left: var(--space-2);
    right: var(--space-2);
  }
}