/* Header: sticky BUE-style topbar and Bootstrap navbar adjustments. */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.topbar {
  display: flex;
  justify-content: flex-end;
  gap: 1.25rem;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.35rem 1rem;
  color: var(--muted);
  font-size: 0.82rem;
}

.nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1rem;
}

.brand img {
  width: 190px;
}

.nav-links {
  font-size: 0.94rem;
  font-weight: 700;
}

.nav-links .nav-link {
  padding: 0.5rem 0.75rem;
  color: var(--navy);
  text-decoration: none;
}

.nav-links .nav-link:hover,
.nav-links .nav-link:focus-visible {
  color: var(--red);
}

.menu-toggle {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--white);
  box-shadow: none;
}

.menu-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(197, 18, 48, 0.18);
}

.navbar-toggler-icon {
  display: block;
  width: 20px;
  height: 20px;
  margin: 0 auto;
  background-image: linear-gradient(var(--navy), var(--navy)), linear-gradient(var(--navy), var(--navy)), linear-gradient(var(--navy), var(--navy));
  background-position: center 4px, center 10px, center 16px;
  background-repeat: no-repeat;
  background-size: 20px 2px;
}

@media (max-width: 900px) {
  .nav-links {
    padding-top: 1rem;
  }

  .nav-links .navbar-nav {
    gap: 0.25rem;
  }
}

@media (max-width: 640px) {
  .topbar {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .brand img {
    width: 150px;
  }
}